Category Archives: Skoda

Timing Belt Replacement on Mk7 Golf 1.0 TSI

Out of Touch, Out of Time – Tips on Timing Belt Replacement on the Mk7 Golf 1.0 TSI.

In this article, our friends over at Gates explain to us why the VW 1.0TSI range has it’s own unique challenges.

VW added the 1L three-cylinder petrol engine to its flagship Golf range in 2015. It’s also a feature of many other VW, Audi, Seat and Skoda models.

The new engine featured non-round pulleys in the Synchronous Belt Drive System (SBDS). The combination helped make significant contributions towards lower overall weights, quieter engines, reduced CO2 emissions and improved driving dynamics.

Now that the new car warranty periods have started to expire, car owners are seeking fresh providers of service and general maintenance work. This means these models are beginning to roll through the doors of many independent garages.

Replacing the timing belts presents new challenges for drive systems specialists. For many, it’s a first encounter with non-round pulleys. For all, it’s a procedure that must not be attempted without the correct set of tools.

Tools required and points to note

As the drive system positioning of the non- round pulleys is extremely important, specific tools are vital to the success of the belt replacement procedure. The Gates timing tool kit (GAT 5140) is required to complete this job correctly. An appropriate camshaft pulley holding tool is required (for example, GAT4844). A crankshaft holding tool is also essential (for example, GAT 5169). When replacing the timing belt, it is good workshop practice to replace the associated metal components at the same time. Gates PowerGrip Kits include belts as well as any appropriate tensioners and idlers.

The water pump is driven by a separate small timing belt without a tensioner. Gates supplies separate belt kits for both the timing belt and the water pump. Note that not all timing belts have a synchronising function.

Twelve-step procedure

1. The first step is to put the engine’s first cylinder at top dead centre (TDC), then lock the crankshaft (locking pin on the side) and the camshaft at the rear.

2. Holding the pulleys in place, loosen the camshaft pulley bolts (right bolt behind plug). Loosen the exhaust camshaft pulley (left) from the conical axle; loosen the belt tensioner pulley bolt while holding the tensioner in place; rotate anti-clockwise (till the retaining lug is situated at the bottom of the slotted hole).

3. Remove the belt.

4. Replace the tensioner and the idler and fit the camshaft pulley locking tool. This will secure the location of the two camshaft pulleys. It is important that they remain in the exact position at which their non-roundness will work to the advantage of the engine (otherwise they will increase belt tension fluctuation rather than reduce it). Note that the dots on both pulleys (at +/- 3 and 9 o’clock (and 12 o’clock) will not line up perfectly.

5. Install the new belt (crankshaft, tensioner, camshafts and idler). Ensure that it is taut on the left side.

6. Remove the little camshaft pulley locking tool. Rotate the tensioner clockwise. The pointer must be 10mm past the notch (window).

7. Bring the pointer back to the middle of the window and torque the bolt to 25Nm.

8. Holding the camshaft bolts in place, lock them to 50Nm. Holding the bolts is a crucial part of the procedure. Install the crankshaft Micro-V pulley. Set a torque of 150Nm and then turn it through another 180 ̊ using the crankshaft holding tool.

9. Remove the locking tools. Rotate the engine, by hand, through two complete revolutions to TDC. Reinstall the locking tools (crankshaft and rear camshaft).

10. If reinstalling the tools proves impossible, restart the procedure from step 1.

11. If this does prove feasible, hold the camshaft sprockets in place and torque a further 90 ̊.

12. Bring the tensioner pointer back to the middle of the notch (25Nm).

Non-round benefits

The non-round pulley design is, initially, difficult to spot. It only becomes obvious when slowly rotating the loosened pulley with your finger or rolling it across a flat surface. The design is vital to the ‘belt dynamic tension optimisation’ process, which is the key to the high performance and low emission qualities of this particular three- cylinder engine. During the intake or suction phase, the piston is moving down, while at the next stroke (compression), it compresses the mixture of air and fuel.

This is followed by strokes three and four – combustion and exhaust. These different strokes cause significant belt tension variation throughout the combustion cycle. This tension variation is countered by means of the non-round pulley design, which delivers a defined amplitude and phasing. The result: optimised belt tension.

How to Fit a Clutch on a Skoda Octavia

Schaeffler Automotive Aftermarket (UK) provides a full replacement guide for the 2006 1.6 petrol model

Recommended fitting time: 3 hours LuK P/N: 622333200

Skoda introduced the Octavia in 1996, before releasing the the generation 3 in 2013. The Octavia has been a popular car since it was launched and is especially liked by taxi drivers due to its low CO2 cost, space and reliability. This model shares the same platform as other VAG group ‘A’ models with a  transverse engine/transmission construction, so there is a good chance this will look quite familiar when the bonnet is raised.

In this guide we’re changing the clutch on a 2006 Skoda Octavia 1.6 petrol that had covered over 95,000 miles and the clutch had started slipping under full load. We used a two-post ramp and two transmission jacks for the repair.

On the ramp

With the vehicle positioned on the ramp, disconnect the air temperature sensor and breather pipe from the engine cover/air box assembly and remove the assembly. Now remove the battery covers, battery and battery tray to gain access to the top of the gearbox. Remove the two “C” clips that secure the gear linkage cables to the linkage (see Fig 1).

fig1
Fig1

Remove the three mounting plate bolts before removing the gear cable assembly and stowing by the ABS unit.

fig2
Fig 2.

Now remove the clutch slave cylinder (the hydraulics don’t have to be disconnected) and unclip the flexible hydraulic pipe from the retaining bracket and swivel up (see Fig 2) – this will give better access to the two bolts. Remove the bolts, then the cylinder and then stow by the ABS unit (see Fig 3).

fig3
Fig 3.

Now disconnect the wiring from the starter motor, pull back the rubber cover, release the red tab from the solenoid multiplug and then release the multi-plug. Now remove the main battery live cable from the
starter motor. The top starter motor bolt can also be removed at this point as well as the two top bell housing bolts.

With the car still on the floor, slacken the N/S/F hub bolt, raise the car and remove the engine under tray. Lower the car to waist height, remove the N/S/F wheel and then the lower section of the wheel arch liner. Now unbolt the N/S driveshaft flange (we used a long extension operating through the wheel arch area), disconnect the driveshaft from the gearbox and raise it above the gearbox casing.

Then remove the hub bolt and slide it out from the hub before removing the driveshaft. Raise the car and unbolt the O/S inner driveshaft flange. Now disconnect the reverse light switch multi-plug and remove the bottom starter bolt and bracket. Remove the bottom gearbox mounting/stabiliser assembly and then the two bolts at the bottom of the bell housing (see Fig 4); these bolts can’t be fully removed (as the exhaust is in the way), but the final threads can be released as the gearbox is being removed.

fig4
Fig 4.

Engine support

We now need to support the engine and gearbox assembly. The problem we have with this vehicle (and we’ll probably see more of it) is that there is no inner wing to locate an engine support beam on. The tool of choice would be an engine support that locates on the front subframe but this was not available to us so we instead supported the engine with a transmission jack and used a second transmission jack for the gearbox. Now remove the gearbox mounting and lower the engine and gearbox until clearance is available for gearbox removal. Remove the final two bell housing bolts and ease the gearbox out, remembering to release the two bottom bell housing bolts. With the gearbox removed, the clutch can now be removed.

The solid flywheel was inspected and the glaze removed from the surface with an emery cloth. Remove the clutch release fork, bearing and snout from the gearbox bell housing and clean the bell housing. Replace the gearbox snout, release fork and bearing, applying a smear of high melting point grease
to the pivot points of the release fork and the input shaft splines.

Clutch assembly

Check the clutch plate fits the input shaft splines correctly. This will also give even distribution of the lubrication and then allow you to wipe off any excess (see Fig 5).

fig5
Fig 5.

Fit the new clutch assembly with a clutch alignment tool and torque to the manufacturer’s specification. Refit the gearbox, starting with the bottom two bell housing bolts during installation and, once bolted tight on the bell housing, refit the gearbox mounting and secure.

At this point we can check whether there is slight ‘freeplay’ on the release fork to confirm correct installation. Refit all components in reverse order and torque to the manufacturer’s specifications. You also need to ensure all electrical items are reset and working correctly as the battery has been disconnected. On start-up the ABS, ESP and electric steering warning lights were illuminated but, by turning the steering lockto-lock we were able to reset the steering. We could then reset the ABS and ESP by taking the vehicle for a short road test.

VW Golf lV, Bora, Jetta IV; AUDI A3, SEAT Leon, Toledo; SKODA Octavia Front Suspension

VW Golf lV, Bora, Jetta IV; AUDI A3, SEAT Leon, Toledo; SKODA Octavia Front Suspension

Fitting video showing correct fitment of shock absorbers and coil springs to the front of:
Audi A3 2WD (09.96-05.03)
Seat Leon (11.99-06.06)
Seat Toledo II (04.99-05.06)
Volkswagen Golf IV 2WD, Variant (08.97-06.06)
Volkswagen Bora, Variant (10.98-09.05)
Volkswagen Jetta IV (10.98-09.05)
Skoda Octavia, Combi (09.96-06.04)

AUDI, SEAT, SKODA, VW – Front Suspension

AUDI, SEAT, SKODA, VW – Front Suspension

Video to show correct fitment of shock absorbers to FRONT of:

AUDI A3/A3 Sportback (05.03-)
SEAT Leon II (05.05-)
Alhambra II (06.10-);
Altea/Altea XL (03.04-)
Toledo III (04.04-05.09)

What is DSG clutch technology?

Since 2008, many new VAG models have been equipped with the new seven-speed dual clutch gearbox (DSG) with an LuK dry double clutch (2CT) system, or – since 2004 – a six-speed wet clutch version which also features an LuK dual mass flywheel (DMF). You will find the six-speed version mostly fitted to larger, high powered vehicles, such as the Passat CC, whilst the seven-speed is being fitted to the ever more popular range of smaller vehicles throughout the range, such as the Polo and Golf.

Best of both worlds
These high-tech state-of-the-art transmissions are designed to incorporate the best advantages of both automatic and manual gearboxes. Automatic transmissions are able to offer superb driving comfort thanks to an automated gear shift and uninterrupted traction, whilst manual transmissions are sporty, fun and economical. A twin clutch system therefore combines the comfort of an automatic with the agility of a manual, along with incredibly smooth and fast gearshifts.

Technically, a DSG is an automated shift gearbox featuring two gear sets which operate independently of each other, thereby enabling fully automatic gear change without traction interruption. There is no clutch pedal and the conventional gear lever has been replaced with a lever with integrated Tiptronic function.

The image below shows a cutaway shot of an LuK Dry Double Clutch

As gear changes are fully computer controlled, it is much more difficult for poor or aggressive drivers to cause damage or premature wear to the system, which should help to optimise the expected service life of the clutch and gearbox components. Like conventional singledisc clutches, the dry double clutch of the seven-speed DSG is also located in the gearbox housing.

There are no drag losses as it is not oilimmersed, increasing engine and fuel efficiency whilst also making repairs less complex. From a technician’s point of view, the gearbox and clutch electronics (mechatronics) are diagnosable, so the system can be read using suitable diagnostic equipment. A full system reset – which puts the mechatronics unit into ‘Learn Mode’ – is required after every clutch replacement, again a simple function as long as you are using the correct equipment.

Since the clutch fitted to the Volkswagen six-speed DSG is oil-immersed (known as a wet clutch) it tends to wear at a much slower rate than equivalent dry clutches. However, there is the possibility that the DMF could wear and require replacement, especially as this transmission has been fitted to Volkswagen Group vehicles for more than 10 years. Fortunately, in a twin clutch transmission – and for the Volkswagen Group DSG in particular – this can be a much simpler task than for a conventional system, as the clutch is not bolted directly to the DMF.

No special tooling or training should be required for experienced clutch mechanics to be able to manage a twin clutch DMF replacement, and as the original equipment manufacturer of the dual mass flywheel for the six-speed Volkswagen DSG, LuK is on hand to supply the replacement DMF unit to the aftermarket as required.

The LuK Dry Double Clutch in-situ

The LuK designed and manufactured seven-speed dry clutch system also features a DMF that is not directly bolted to the flywheel and is just as simple to replace when worn. LuK engineers have also been investigating the potential for a complete replacement twin clutch kit solution for the UK aftermarket.

A range of original equipment components, specific tools and bespoke training programmes have already been designed and developed, and LuK is currently assessing the size of the opportunity for independents to offer the owners of vehicles coming out of the warranty period a viable aftermarket option when it comes to buying a replacement twin-clutch.

Due to its success with the DSG, the Volkswagen Group has already announced that more than 40% of the cars they produce will be fitted with a dual clutch system by 2012, and this has not gone unnoticed in the automotive world. With the improved fuel economy and lowered emission levels it can help provide, many other vehicle manufacturers are now beginning to specify twin clutch transmission systems to help keep in line with ever more stringent Government legislation.

Vehicle producers that are currently using twin clutch systems, or who are developing new versions to use in their range include: Audi, Ford, Honda, Hyundai, Mercedes-Benz, Renault, Seat and Skoda. LuK, as ever, will be at the forefront of this rapidly growing market, thanks to its ongoing commitment to innovation, technology and quality.

The benefits of a dual clutch system

• Combines the ease of an automatic transmission with the responsiveness of a manual gearbox
• Similar to an automatic transmission, but with excellent fuel efficiency
• No power interruption during torque transfer
• Significant reduction in CO2 emissions

Clutch replacement – Skoda Octavia

The Octavia has proved a popular purchase in the UK after gaining a reputation for reliability and qualit yand, as a result, it is now a popular sight in the aftermarket scene. Nothing out of the ordinary is needed to complete the job, the only special tools required are a transmission jack, an engine support cradle and a long axle stand. A two-post ramp was used in this example however a four-post ramp may not provide enough clearance.

For safety reasons its considered best practice to disconnect the battery earth lead before commencing work. If the vehicle has alloy wheels it may be fitted with anti-theft wheel bolts, so make sure you have the key before you start.

Open the bonnet and lift off the engine cover. Remove the battery cover and disconnect the battery terminals. Unplug the Mass Airflow Sensor (MAF) and remove the air filter housing (pictured below) attached to the front slam panel.

Continue to remove the remainder of the housing and the air filter assembly connected to the inlet manifold. Remove the clamp holding the battery in place and lift the battery out of the tray.

Remove the front part of the battery surround and undo the fixing bolts (pictured below) on the base of the battery tray.

 

Remove the tray and disconnect the gear linkage cables (pictured below) and the securing bracket.

Undo the small gearbox steady bracket and remove the slave cylinder. Remove the earth connection (pictured below) from the starter motor bolt head and remove the bolt.

Unplug the reverse light switch (pictured below) and undo the upper bell-housing bolts.

Use the engine cradle to support the engine and remove the gearbox mounting bracket. Raise the vehicle and remove both front road wheels. Undo both front hub nuts and remove the intercooler pipe (pictured below) for better clearance.

Undo and release the lower arm nuts and the gearbox rear steady bar. Undo the lower starter motor bolt and stow the unit to one side. Remove the nearside wheel arch liner and remove both driveshafts. Remove the inspection back plate on the gearbox and remove the exhaust manifold support bracket (pictured below).

While supporting the gearbox remove the final lower bell housing bolts and lower the gearbox carefully to the floor. DMF inspection With the clutch removed, check the dual mass flywheel (DMF) for signs of heat stress and evidence of grease loss. The DMF should also be tested for freeplay and rock between the primary and secondary masses (LuK tool number 400 0080 10 is specifically designed for this purpose on all LuK manufactured DMFs). Full instructions and tolerance data for all LuK DMFs are contained on a CD which comes with this special tool.

Clean the first motion shaft splines and any debris from the bell housing (especially important when a release bearing has failed). Put a small dab of high melting point grease (not a copper-based product) on the first motion shaft splines and make sure the new driven plate slides freely back and forth. This not only spreads the grease evenly but also makes sure you have the correct kit. Wipe any excess grease off the shaft and driven plate hub. Using a universal alignment tool and checking the driven plate is the correct way round (note “Getriebe Seite” is German for “Gearbox Side”) the clutch can be bolted to the flywheel evenly and sequentially.

Before fitting the gearbox make sure the locating dowels are in place and not damaged. Refit any that have become dislodged and refit the gearbox. Make sure the gearbox bell housing bolts are secured before lowering the jack. Refitting is the reverse of the removal.

Accessory Belt Drive System maintenance – Various models

Vehicle make(s): Various, including Audi, SEAT, Skoda and VW models
Engine: 1.9 TDi 8V

Developments at OE level mean that different models in the same vehicle range may be equipped with different Synchronous Belt Drive Systems that require specific sets of tools to complete the job. While this requires additional garage investment that must be recovered, it is the introduction of new drive system components in the ABDS that is likely to add significantly to the overall cost of drive system repairs.

When it comes to ABDS maintenance, things are tight and not just in relation to the tension on the belt. Garage customers have rarely been more aware about the price of parts and the cost of vehicle repairs, but it’s hard to convince them to spend now and save later.

Gates, one of the world’s largest manufacturers of OE belts and tensioners, argues that if a symptom is cured but the cause of the problem remains undetected, the vehicle will be back for a rectification job. And next time, the problem may be more serious.

Vibration control
In order to deal with a lot of vibrations in the ABDS, modern engines are equipped with technology such as Overrunning Alternator Pulleys (OAPs) and Torsional Vibration Dampers (TVDs). Until recently, these components were rarely encountered in the aftermarket, let alone considered parts for inspection at belt replacement time. Now found in models in increasing numbers, they are expensive to replace, but even more expensive if not replaced as part of a preventive maintenance schedule.

Function and role
TVDs have important roles to play inside modern cars. In order to extend the operational lifetime of components powered by the belt, they absorb vibrations from the crankshaft. If the TVD fails, or its ability to dampen vibrations reduces through wear, there is a significant risk of damage to the belt and possibly the driven accessories. If left unchecked, a broken crankshaft becomes a very real possibility.

OAPs are more recent additions to ABDS technology. These have been designed to overcome variations in different component speeds within the drive. OAPs are special kinds of pulleys, which allow alternators to continue to run on when the engine speed decreases. This reduces the potential for belt slippage on the alternator pulley. Reduced Noise/Vibration/Harshness (NVH) and increased component life are important benefits.

Consequence of failure
By absorbing vibration and allowing the engine to perform to its true potential, OAPs and TVDs are inevitably subject to wear and begin to fail.

For example, an OAP that is underperforming generates vibrations that adversely affect the smooth running of the belt. The cumulative affect is to increase stress on the tensioner bracket, which begins to experience material fatigue. The ultimate consequence is the rupture of the tensioner bracket.

Analyses of examinations by Gates Inspectors on the aforementioned models show that rupture related to OAP wear will always take place at the same point: shearing takes place just above the connection of the tensioner bracket with the hydraulic damper. In such cases, shearing of the tensioner bracket is a symptom of the additional vibrations generated by the worn OAP and not the cause of the premature belt failure.

Mistaken identity
Unfamiliar with the components, mechanics often confuse the symptoms that are generated by wear of these components as problems with the belt. This is especially true in the wake of scheduled maintenance, where the OAP has not been considered for replacement at the same time as the belt.

Customers should be advised of the potential risks to the drive system if not replaced.

Conclusion and recommendations
OAPs as well as TVDs are not designed to operate for the lifecycle of the car. They are service items. So, it makes sense to replace them at the same time as the ABDS belt.

Wheel bearing replacement – Skoda Fabia

The Skoda Fabia was introduced in 1999 and was built until it was face-lifted in 2007. During this time the Fabia forged itself a reputation for high reliability and quality. The MK1 has sold over 170,000 models in the UK and as a result we are seeing a lot of these models coming into the aftermarket scene. The type of bearing used on the Fabia can be a little tricky to fit because it has to be pressed into the hub and during this process, if done incorrectly, you can damage the bearing prematurely. But don’t worry because the bearing experts at FAG will make it much easier for you with this handy guide.

Firstly, check to see if the vehicle has alloy wheels fitted, if it has it may be fitted with anti-theft bolts so you’ll need to find the key. Raise the vehicle on a ramp (although the job could be done on the ground if necessary) and remove the wheel on the relevant side. When possible we recommend that you replace bearings in pairs, as chances are the bearing on the opposite side could be just as worn as the one you are replacing.

Removing the hub
Undo the large hub nut securing the driveshaft and release the shaft from the hub. Undo the two bolts securing the calliper to the hub and remove the assembly and secure it out of the way. Remove the brake disc and the metal bracket securing the brake pipe to the hub.

Undo the lower ball joint bolt (pictured below) and release the lower arm from the hub.

Undo the nut securing the steering rack to the hub and release it. Undo the bolt securing the hub to the suspension strut (pictured below) and release it from the strut.

For easier access you can undo the anti-roll bar link attached to the suspension strut as it will enable you to manipulate the strut better.

With the hub removed the bearing can now be pressed out of the hub. In this article we are using a special tool which is able to extract the bearing from the hub and press it back in. For safety reasons it’s a good idea to reattach the lower arm if you are using the tool on the vehicle, this will ensure that the hub is more secure. Place the pressing pins into the correct five or four stud arrangement and slide the two-piece collar (pictured below) around the bearing.

Bolt the tool to the hub (pictured below) and start to tighten the tool using a socket or spanner.

This will start to pull the bearing out of the hub (pictured below).


Important checks
Once the bearing has been removed, take time to check that the hub profile is perfectly round and not damaged. The outer race of a bearing will always take the shape of the hub its being pressed into, so if the hub has been damaged and is not perfectly round this could prematurely wear the bearing over time. You will also notice that the old bearing had a locking ring around the outside which has now broken (pictured below).

This is completely normal as the new bearing will have a new clip fitted to it. But don’t forget you will need to make sure that all the remnants of the old clip are removed from the hub.

When you fit the bearing into the hub, make sure you press on the outer race and not on the flange. By doing this you ensure that the pressing force is not transmitted through the balls or rollers in the bearing but only through the outer race. In our case, we are using the tool to ensure this happens. To fit the bearing, install the collar around the new bearing and mount the pressing pins onto the ring through the holes in the flange. Offer the bearing up to the hub and bolt the assembly in place (pictured below).

The tightening of the tool will now press the bearing into the hub and you will hear a loud ‘click’ as the locking ring locates into the hub assembly. Fitment of the remainder is the reverse of the removal.

Winter coolant servicing – profit opportunities and tips

Contemporary coolants have become every bit as ‘vehicle specific’ as engine oil. There are now three very distinct technologies used as ‘original fill’ by vehicle manufacturers. These coolants all perform the same essential functions – i.e. prevent freezing and overheating, while simultaneously protecting engine and cooling system components against corrosion and erosion. But their chemical additive formulations  – also called ‘packages’ – are entirely different, one from another, and can’t be mixed or substituted.

It means that for technicians to protect warranties, vehicles presented for servicing must be re-filled or topped up with the exact type of OE coolant that went in on-line. And that makes winter servicing with manufacturer-approved coolants a significant profit opportunity; an opportunity that switched-on independent workshops should be quick to grasp.

The most recent research conducted for Comma’s Professional Partner Programme revealed that franchised dealers typically charge £120 – and more – for a coolant drain and refill. Yet with the latest coolant re-filling equipment, the job can be done professionally, using the correct, manufacturer-approved coolants, in under half an hour at a charge-out rate around half that figure. In fact, three vehicles an hour could easily be serviced, making this a viable ‘while you wait’ proposition with high returns. The equipment is readily available, easy to use, requires no special training, and eliminates the need for thermo recycling – i.e. running the engine hot and cold to bleed off air.

Coolant technologies – What’s the difference?

For the European passenger car and LCV market, the three types of coolant specified by vehicle manufacturers are:

1) Silicate based technology.

2) OAT (Organic Acid Technology) based technology.

3) The most recently developed technology, based on a combination of both Silicate and OAT, and known as Si-OAT.

Silicate products have a 2/3 year service life before replacement; OAT and Si-OAT products have a longer, 5 year service life.

BASF Glysantin® coolants are the original equipment (OE) fill to most European VMs. These are designated either G48® (Silicate) G30® (OAT) and G40® (Si-OAT). The last of these – G40® – was specially developed in collaboration with VAG Group, and is  manufacturer-approved for all VAG (Audi, Bentley, Bugatti, Lamborghini, SEAT, Skoda and Volkswagen) models from 2005 onwards, plus selected Mercedes Benz and Porsche models..

Finding the right coolant

Comma’s coolant application data covers the entire UK vehicle park, dating back over 30 years (visit the VRN look-up at www.CommaOil.com) with every one of the 7,000+ recommended applications being covered by a 100% guarantee of compatibility and quality.

Technicians’ tips

For best coolant practise, follow these guidelines……and don’t forget to inform your customer about what you have done, and why.

  • When the additive package is ‘spent’, replace all coolant to restore full protection.
  • Check the vehicle handbook and always fill with the correct, manufacturer-approved or OE compliant coolant.
  • Never mix coolant types – it cancels out their individual protective properties and could actually lead to mechanical damage.
  • Use only de-ionised/distilled water – never tap water – to dilute concentrated coolants.
  • Flush old or dirty systems with cleaner before re-filling.
  • Visually check the entire coolant system for leaks after re-filling.

Brush up your engine coolant knowledge by visiting the Comma online training academy at

Why you should never compromise on the quality of brake hoses

Perhaps less publicised, but of no less importance to a vehicle’s braking system, is the humble brake hose. These perform a simple yet deeply important function: the transfer of brake fluid to the brake caliper or wheel cylinder, forcing a brake pad onto disc. In other words, the behind-the-scenes work between the depression of the brake pedal and the vehicle stopping.

Why the requirement for a hose change?
Car owners generally expect to replace brake discs and pads during a vehicle’s lifetime, in general, due simply to wear. Thankfully the deterioration of brake discs and pads is usually associated with very clear, tangible signals, such as noise on application, reduced performance and visible disc and pad abrasion.

However, the majority of vehicle owners are simply unaware that ‘wear’ also applies to brake hoses, with numerous reports stating that many owners will never change, or even think to replace the component. Perhaps this is not solely the fault of the end user; it would appear that very few garages and mechanics regularly recommend hose replacement before its absolutely necessary, or prior to some degree of failure. As a general rule brake hoses have a life cycle of around five years, and while this can change dependent upon use and climatic conditions, at some stage all will require replacement.

Warning signs

Fitting-picThere are a number of reasons why brake hoses deteriorate, which includes a multitude of factors such as the temperature of the caliper and brake drum, the aggressive nature of braking fluid, the consistent movement of the hoses during driving, a hose’s susceptibility to varying weather conditions and changes in temperature and the corrosion associated with road salt. The fact is brake hoses lead a hard life, and as such, must be viewed as wear and tear items in the same vein as the other major components of the braking system.

When a brake hose deteriorates it will start to allow water permeation due to the hydroscopic nature (attracting water) of brake

fluid. As the water ratio increases within the brake fluid, the boiling point of that fluid lowers dramatically; in fact just 4% of water content within the brake fluid could cause the fluid to boil, which in turn switches to a gas state. As gas is less dense and more compressible than liquid, so drivers will feel their brake pedal start to travel further while braking performance is reduced or eliminated entirely. This could happen progressively or (if a crack or tear appears) instantaneously – the effects of which does not bear thinking about.

This condition, known as ‘Vapour Lock’, can prove to be extremely dangerous and the signs that lead to it are visible only through a detailed visual and physical inspection.

Signs of impending failure include wet or pasty areas (usually around the back of the fitting ends), bubbles or blistering across the surface of the hose, small cracks on the outer layer as well as chafe marks. Less obvious signals also include soft or easy to bend as well as hard or brittle hoses, and, from the driver’s seat, a spongy or less resistant brake pedal feel.

Aftermarket challenges
In recent times both the VAG group (Volkswagen, Audi Seat and Skoda) and Vauxhall have adopted increasingly elaborate brake line systems that run in parallel along each side of the vehicle’s axle and these use a veritable jigsaw of pre-bent steel metal piping within their construction.

In essence this is in order to deter aftermarket brake specialists from replicating the design, and while Apec is one of the few who has been able to integrate this more detailed specification and production into its manufacturing process and product range, supplying brake lines that match this new OE specification precisely, there are some companies that are unable to do so, instead supplying flexible tubing (or even metal tubing) that requires alteration and bending on site.

 

Apec’s alternative
Hose-ImageManufactured on advanced, automated production lines to exacting tolerances, all Apec hoses feature a multi-layered construction to offer exceptional resistance to heat, the ozone and weather conditions. Additionally, rigorous testing procedures include assessment of corrosion within the brake hose itself, as well as analysis of leakage, whip and burst pressure trials up to 200 bar, volumetric expansion and brake fluid compatibility testing.