clutch bleed after clutch change

chrissgoduk

Active Member
Jun 22, 2011
179
0
somerset
Hi all just put a new clutch in my leon fr mk1 tdi
do i have to bleed the clutch through
cheers guys no its a dumb question but thought id ask any way
 

chrissgoduk

Active Member
Jun 22, 2011
179
0
somerset
No just pedal seems high bit worried its gunna slip ..
Also i changed it beacuse it was hard to go in gear its alot better but dont feel perfect.
 

Muttley

Catch that diesel!
Mar 17, 2006
4,987
31
North Kent
You've taken the gearbox out. Did you somehow manage to do that without disconnecting the slave cylinder? If so then no. Otherwise, yes.
 

Seatmann

Rough around the edges
Sep 16, 2010
5,575
10
Scotlanda
You disconnected the pipe? And yes, you bleed it through that little nipple but it sounds like it's working.
 

Muttley

Catch that diesel!
Mar 17, 2006
4,987
31
North Kent
You have a six-speed gearbox with the slave cylinder integrated into the release bearing, round the gearbox input shaft.

Here is a cut-and-paste of a previous answer covering both clutch and brake systems.


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 bubbles 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

Right (offside) rear
Left rear
Right front
Left front.

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


The Mk.60 unit 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

Left (nearside) front.
Right front
Left rear
Right rear

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.
 
Last edited:

BenG

Ben
Oct 26, 2011
484
0
Cove Bay, Aberdeen
Thanks Muttley, that's useful information for next time I have to do this job.

I've tried the Gunson Easibleed but every time I use it it just fills the brake fluid reservoir with fluid which then pisses out of the cap all over the engine [:@], even when using a tyre pressure of just 10psi to supply the kit...

The seals in the various reservoir caps supplied kit don't seem to work. I think the answer is maybe to run it 'dry', with no fluid in the bottle, and just keep topping up the fluid reservoir...
 

Muttley

Catch that diesel!
Mar 17, 2006
4,987
31
North Kent
If fluid is leaking out of the cap under pressure then the cap isn't sealing onto the reservoir. Check the reservoir top doesn't have any nicks or bits of plastic flash sticking up. You must get an airtight seal on the reservoir or it won't work.
 

chrissgoduk

Active Member
Jun 22, 2011
179
0
somerset
Cheers guys went to bleed system but now got no pedal at all just keep getting air bubbles and no pedal.
im not using a pressureised system though is that my problem????
 
sometimes master cylinders go tits up after puttting clutch in. also check the rubber seal is still in the bit where nipple comes out where the pipe clicks in the box mate if that seal is missing it wont bleed up but i must have done over a hundred clutches on pd's and have know the master under pedal in car go wrong
 

Seatmann

Rough around the edges
Sep 16, 2010
5,575
10
Scotlanda
Get a pressure bleeder on it, I fitted a new master cylinder to a focus last year and it took forever to bleed. I had to keep putting the fluid back through till eventually it just worked.
 
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