Lcr brake bleeding

Gunson eezibleed is your best bet for self bleed.

Rear right
Rear left
Front left
Front right
Clutch
Master cylinder x 2

Going by the horror stories I'd never manually bleed through the pedal, loads of people have damaged the seal in the master cylinder doing so.

Pressure or vacuum bleed and in the order James said above.

Also your ABS modulator may need bled too through a VAG COM.

If you're not sure it might be worth paying the 50 quidish and get the dealer to do it

Whether its a misconception i dont really know.


It wasnt the mastercylinder that failed when i pedal bled my brakes, more i killed the servo either by splitting the diaphragm or splitting an internal seal to the pedal,


new servo fitted and used gunson easybleed but still didnt clear the lines fully


2 man job, with engine running one person to bleed one to pump. but by no means exceed half pedal travel ive bled up 3 times this way since, and never had an issue, !

it was a good 6 hours changing a brake servo with engine in situ!

start at furthest from the M/C and work opposite corner to corner , and bleed both sides of the MC before and after,

I've used Gunson eezibleed and I break everything but this was successful...

O I did round all my bleed nipples and had to file them down a size

As I've said before:


Brake and clutch bleeding on the Golf Mk.4 platform

Hydraulic fluid should be changed at intervals of two years or less. The fluid deteriorates by absorbing water over time: mileage is not a factor. If it's more than two years since it was done, aim to change the whole contents of the system. I've not done this on a Mk.4 and don't know the quantity; the change is performed by bleeding in the correct sequence until the fluid coming out of the caliper changes colour. Use Dot 4 hydraulic fluid.

Always keep the fluid level in the reservoir at or near the full mark. If you let air into the system you have to start all over again.

You should run at least 0.25 litres of fluid from each caliper or slave cylinder. You will need more than 1 litre of fluid to complete a full bleed of the system.

It is not recommended to bleed by pumping the pedal, as there have been many instances of master cylinder seals being damaged using this method. If the master cylinder seals are damaged the master cylinder must be replaced.

I understand that people have succeeded in using the pedal method, without damaging the seals, by not pushing the pedal all the way to the floor.

The failure seems to be that the seals are caught and flipped round, so they fail to seal any more. I assume that there is a ridge worn in the master cylinder at the bottom of its normal stroke, which you go past once the resistance of the caliper or slave cylilnder is removed by opening a bleed nipple.

Use a pressure bleeding kit (Gunson Easibleed or equivalent).

The Clutch System
The clutch is fed from the same hydraulic reservoir as the brake system. Its master cylinder is fed from a pipe coming off the reservoir side, a small distance up from the brake connection which is in the bottom. This means that the clutch will fail first if you have a hydraulic leak. This can be a warning sign - if you get clutch disengagement problems, check the hydraulic fluid level.

The clutch will need to be bled if you change the slave cylinder on the gearbox or if air gets in by letting the level get too low. There is only one bleed nipple, at the slave cylinder end.

For cars with a five speed gearbox the slave cylinder is on the outside of the gearbox with an obvious bleed nipple.

The six speed gearbox has the slave cylinder integrated with the release bearing, inside the bellhousing and mounted around the gearbox input shaft. There is a bleed nipple on the outside of the bellhousing, close to the gearshift mechanism. Pressure bleed, then with the pressure kit still in place, push the pedal down and release it quickly to get any small bubble out of the long pipe to the middle of the bellhousing. Now bleed some more fluid through.

After bleeding, pump the clutch pedal up to pressure before starting the car again.


The Brake System

If you have any doubt at all about there being air in the master cylinder, bleed it first. There are two bleed nipples, one for each circuit. You should then bleed the front left and right calipers simultaneously, then the rear left and right calipers. This is to get any air out of the master-cylinder-to-ABS-unit pipes.

All the manuals say that the correct bleeding sequence depends on the type of ABS system you have installed.

The two possibilities are Mk.20 or Mk.60.

The Mk.20 unit is mounted flat, with the hydraulic unit on top, and has six hydraulic pipe connections on the left-hand face of the hydraulic unit. The two topmost are from the two halves of the master cylinder.

My 2001 Toledo TDI 110 SE had a Mk.20 unit.

The bleeding sequence for the Mk.20 unit is

This is furthest-to-nearest, as the ABS unit is on the nearside of the engine compartment.



The Mk.60 is mounted on the nearside wing with the hydraulic unit towards the engine. The two pipes from the master cylinder enter the uppermost side of the hydraulic unit and two pipes go to the rear brakes from the top of the hydraulic unit just below. The pipes to the front brakes are attached to the opposite side of the unit, and can only be seen from the bottom of the engine bay.

My 2004 Toledo TDI 150 Sport has a Mk.60 unit.

The bleeding sequence for the Mk.60 unit is

I assume that this is because the unit is mounted vertically and the front brakes are fed from pipes attached to the lowest part of the unit.

If air has got into the ABS pump then VCDS or a dealers diagnostic computer may be needed to exercise the ABS unit and remove the air bubbles.

I tried bleeding my LCR using the pedal - never again. It was the biggest ballache. In the end I took it to my local mechanic and paid for the bloody thing to be pressure bled. Just pay mate, the hassle is really not worth £20.

As for the damage to the master cylinder, this is due to the brake pedal never being fully depressed under normal usage. With no pressure in the system, the pedal can go to the floor, and therefore the piston in the master cylinder can move along its full length. Where the problem comes in is here the piston doesn't normally move along its full length, the seals dry out/crack/rot - you name it. When the piston moves past these seals, it disturbs them causing the damage.

I'm not sure if its me or I did actually read some where that you can activate the abs by starting the engine with the esp on put it in gear then press brake pedal should kick the esp in.

Someone with greater knowledge will be able to say ya or nay.