Major trouble bleeding brakes!

[Wesleyvr6 10]

Now I have everything on the abs side running without any faults I started to bleed the brakes! Me and my friend(Audi mechanic) have tried 4 times now to bleed the brakes! The problem we have is the pedal seems fine after pumping the brakes once, but the next time you come to press the brake they seem to go to the floor! We definitely have no leaks and have pumped at least 1.5 litres through each caliper! We have also bled the abs pump! Where are we going wrong? Everything worked fine before I did the 312 upgrade and new rear mk4 calipers? I know a lot of fluid may have leaked out of the system as we were upgrading everything over a couple of days! Thanks in advance

[davidwort 0]

did the system/ABS unit run dry, as you have changed hoses so can't have clamped them to stop fluid draining?

Is the pedal behaviour totally different with the engine on/off, could be servo related.

Not sure if you can cycle the ABS unit with diagnostics kit to remove air, perhaps someone else can confirm.

[quicky1980 0]

i had a nightmare bleeding my brakes after fitting mk4 rear callipers. Just went round everysingle bleed nipple, on the calipers, abs module and servo and still wasnt great but useable. over time it settled itself. good luck mate

[Wesleyvr6 10]

did the system/ABS unit run dry, as you have changed hoses so can't have clamped them to stop fluid draining?

Is the pedal behaviour totally different with the engine on/off, could be servo related.

Not sure if you can cycle the ABS unit with diagnostics kit to remove air, perhaps someone else can confirm.

I think it may of done yes, we've been trying again all night and still no joy! I'm slowly loosing it with them now as I've spent weeks and lots of cash bringing this car back to like new! Just need the brakes sorted then it's not time and a drive in the beast after owning it for nearly 10 months!

[C5 OEM 0]

I took mine to vw in hyde mate, cost me £50 and they drained it all,put new fluid in and bleed the system...

[fla 9]

as quicky has mentioned, over time they should settle. After bleeding, did you allow any final 'gravity bleeding' from each caliper - just opening the nipple enough to let fluid and air trickle out into a sealed container and closing after a few minutes?

[RW1 0]

If the ABS block has been allowed to drain, then you will not be able to purge through without a special test harness & control box to open the various valves.

 

The test harness & control box hooks upto the Valve Block's 15 pin front face connector and uses the valve control wires (10 wires). While the system is under pressure, the internal valves are then opened via the Test Control box to purge out the air pockets.

 

The kit is (was?) available in the USA but wasn't VW, iirc it was for Rovers. The VW workshop advises to cap off the hyraulics conections when the Valve Block is disconnected but there is not "tool" to rectify an internal drain/air pocket problem. The Valve Block is replaced as a whole.

 

VCDS & VW Diagnostics VAS system do not have this capability. This because there is no Output Test - 03 option programmed into the Teves 04 - ABS ECU firmware to operate the ABS pump & Valve block valves.

 

(Unlike my Scirocco Mk3 where I can go in and make the ABS pump run & all the ABS/EDL valves operate.)

 

.

 

---------- Post added at 10:44 AM ---------- Previous post was at 10:33 AM ----------

 

The VW workshop advises to cap off the hyraulics conections when the Valve Block is disconnected but there is not "tool" to rectify an internal drain/air pocket problem. The Valve Block is replaced as a whole.

 

I don't think you have got to this situation with the Valve Block. Re-look at the calipers you have fitted.

 

.

 

---------- Post added at 11:39 AM ---------- Previous post was at 10:44 AM ----------

 

Maybe worth taking note of this, particularly the last post. Very similar to this topic's problem.

 

http://www.clubgti.com/forum/showthread.php?t=200566

 

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[james153 0]

I bled my abs unit through even though i had all new pipes and calipers and the unit had been dry for 2 years.

Have you bled the master cylinder??

[elliott 10]

Just a thought but are you using a gunson eezibleed kit? It's worth buying one and giving it a go, it's saved me hours of pumping pedals and saves a lot of head aches.

Edited March 3, 2012 by elliott

[Wesleyvr6 10]

If the ABS block has been allowed to drain, then you will not be able to purge through without a special test harness & control box to open the various valves.

 

The test harness & control box hooks upto the Valve Block's 15 pin front face connector and uses the valve control wires (10 wires). While the system is under pressure, the internal valves are then opened via the Test Control box to purge out the air pockets.

 

The kit is (was?) available in the USA but wasn't VW, iirc it was for Rovers. The VW workshop advises to cap off the hyraulics conections when the Valve Block is disconnected but there is not "tool" to rectify an internal drain/air pocket problem. The Valve Block is replaced as a whole.

 

VCDS & VW Diagnostics VAS system do not have this capability. This because there is no Output Test - 03 option programmed into the Teves 04 - ABS ECU firmware to operate the ABS pump & Valve block valves.

 

(Unlike my Scirocco Mk3 where I can go in and make the ABS pump run & all the ABS/EDL valves operate.)

 

.

 

---------- Post added at 10:44 AM ---------- Previous post was at 10:33 AM ----------

 

 

I don't think you have got to this situation with the Valve Block. Re-look at the calipers you have fitted.

 

.

 

---------- Post added at 11:39 AM ---------- Previous post was at 10:44 AM ----------

 

Maybe worth taking note of this, particularly the last post. Very similar to this topic's problem.

 

http://www.clubgti.com/forum/showthread.php?t=200566

 

.

Thanks for your info buddy.

I bled my abs unit through even though i had all new pipes and calipers and the unit had been dry for 2 years.

Have you bled the master cylinder??

Yes once but going to try again tomorrow

 

Just a thought but are you using a gunson eezibleed kit? It's worth buying one and giving it a go, it's saved me hours of pumping pedals and saves a lot of head aches.

no just the old fashioned way, I think my friend has one of these, I'll see if I can get hold of it.

[RW1 0]

UK brakes should be vacuum bled as I've written on here before. VW don't use a pressure bleeder system. They instruct to vacuum bleed.

 

Pumping the master cylinder can lead to over heating of the old seals in the master cylinder and failure. There will be no real warning other than the pedal feels a little jittery as you press it (seal rubbing on the master cylinder wall). Do slowly and give rests every 4th pump action to let the master cylinder seals to cool, about 10 mins rest time.

 

.

 

---------- Post added at 11:47 PM ---------- Previous post was at 11:41 PM ----------

 

Have vacuum bled mine every two years for the last 14 years and the brakes have never given problems afterwards.

 

The other tip is never reverse the caliper pistons inward as back pressure can blown the ABS valve block valves. Always open the caliper bleed nipple to let out the brake fluid if you have to push back the caliper piston. Known more than one owner ABS valve block ruined before now.

 

.

[Wesleyvr6 10]

UK brakes should be vacuum bled as I've written on here before. VW don't use a pressure bleeder system. They instruct to vacuum bleed.

 

Pumping the master cylinder can lead to over heating of the old seals in the master cylinder and failure. There will be no real warning other than the pedal feels a little jittery as you press it (seal rubbing on the master cylinder wall). Do slowly and give rests every 4th pump action to let the master cylinder seals to cool, about 10 mins rest time.

 

.

 

---------- Post added at 11:47 PM ---------- Previous post was at 11:41 PM ----------

 

Have vacuum bled mine every two years for the last 14 years and the brakes have never given problems afterwards.

 

The other tip is never reverse the caliper pistons inward as back pressure can blown the ABS valve block valves. Always open the caliper bleed nipple to let out the brake fluid if you have to push back the caliper piston. Known more than one owner ABS valve block ruined before now.

 

.

Would ou recommend I use the eazibleed pro bit of kit then as this uses suction rather than pressure? Thanks again for all your help! I will get there eventually I promised myself haha!

[RW1 0]

Seems a bit expensive plus you need an air line.

 

Mine is a hand pumped vacuum/drain reservoir in a tower system with a separte feed bottle topping up continuously as the reservoir drains.

 

Unfortunately tonight at the mo, the www USA links for me are not working so I can't locate examples on Ebay to show you.

 

.

[davidwort 0]

UK brakes should be vacuum bled as I've written on here before. VW don't use a pressure bleeder system. They instruct to vacuum bleed.

Apologies if you've explained before, but why can't you pressure bleed from reservoir? I've used an ezibleed with good results on various abs cars, worried now if it can cause a problem!

[RW1 0]

This is the unit I have. Hand pumped, no air line needed. How prices have gone up since EuroCarParts sold it 14 years ago for £30. It will be in the region of £60 - £75. Known as Brake Fluid Changer CJ236.

 

[ATTACH=CONFIG]54321[/ATTACH]

 

In use on my Sciroccco. Can't remember why I went through the engine bay to the front left caliper that day 12 years ago. It may have just been to get the colour of the fluid against the car body background as thats the next photo in the sequence that day. It hadn't been changed by the previous owners since new (10 years at the time).

 

[ATTACH=CONFIG]54317[/ATTACH]

 

Has a lot of uses. The hand pump doesn’t touch the waste fluid chamber, so it doesn’t matter what is sucked in, brake fluid, gear oil, engine oil.

 

Bit hard to find as the whole kit including the reservoir feed bottle that sits on top of the brake/clutch reservoir these days. The kit seems to be available still through Taiwan if you put in Google “Brake Fluid Changer CJ236” it comes up and can sometimes be found on Ebay. There's a 6 litre version for sale now from Wolverhampton but I can't see the Brake Reservior (blue container above) with it. The Ebayer is selling several in the current auction. http://www.ebay.co.uk/itm/SEALEY-Bra...item3cbd0ab7a9

 

----------------------------------

 

The VW manual (European) makes a distinct remarks about bleeding. But they would not put it in the manual unless it was necessary.

 

“When the system is open, avoid working with compressed air and avoid moving the vehicle”

 

plus this warning also appears in VW's manuals....

 

[ATTACH=CONFIG]54313[/ATTACH]

 

Hence why I use a vacuum method.

 

Yes, VW workshops do use pressure bleeding but their equipment feeds brake fluid with no risk of compressed air. So pressure bleed is OK if done correctly.

 

But with Eazibleed don’t you run the risk of running dry unless care is taken. Eazibleed handbook warning.......

 

NOTE: The pressure vessel should hold enough fluid to complete the bleeding operation. If the level in the pressure vessel approaches the minimum level line, disconnect from the tyre and refill, proceed again.

 

Plus Eazibleed recommend a max. working pressure of 20 psi typically which exceeds the workshop manual warning about bleeding/changing brake fluid. So you probably been below the 15psi (1 bar) level, so no need to be concerned, just more cautious in future.

 

Also, during the first brake fluid change I had done at the dealers in 1997, they managed to flood the engine bay with brake fluid in the rear right side and into the fuel pipe body channel on the underside of the floor pan. Presumably the cap connection had come off the brake fluid reservoir and the resulting situation flowed brake fluid out all over the place. Fortunately no real damage to the engine bay paintwork was done as I managed to get the area soaked in water to flash it all away. Call it natural aversion to pressure bleeding. Once bitten, never again!

 

I just avoided the whole issue and at £30 back then in 1998 for a 4ltr vacuum system collection reservoir and 1litre header bottle to top up the reservoir fluid, I am covered not to push/suck air into the system while flushing through one calliper.

 

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[VW_OwneR_85 1]

sorry i havent read all the comments, so you have fitted new calipers? and bled the calipers but still spongy?

i had that when i fitted mk4 golf rear calipers,{i didnt drain down the system neither did i let it draw in air} i needed to use them so that the pads can wear square with the disc, after useing my car for awhile my brakes are now fine,work and feel as they should, but thats just my take on my brakes, and may or may not be related to what problems you may or may not have....

[Critical_Mass 10]

The other tip is never reverse the caliper pistons inward as back pressure can blown the ABS valve block valves. Always open the caliper bleed nipple to let out the brake fluid if you have to push back the caliper piston. Known more than one owner ABS valve block ruined before now.

 

.

 

I didnt know this. Ive only just changed the front pads on my car and had to push the piston all the way back. I did not open the bleed nipple when i did this.

[davidwort 0]

I didnt know this. Ive only just changed the front pads on my car and had to push the piston all the way back. I did not open the bleed nipple when i did this.

 

 

 

I wouldn't worry too much,I've done it before on newer vw abs systems too, but It's just something worth remembering that reduces the risk of damaging something, you don't want to keep the old fluid low down in the system by the pistons anyway as that's where dirt and moisture settles anyway.

[elliott 10]

Blow or suck it's all good :) Eezibleed kit is cheap and efficient but if you run the reservoir dry then well... you've only yourself to blame. I'd imagine sucking the reservoir dry would result in the same problem? Also i'd advise you use a bike wheel and not the one on your car, that way you'll not risk putting too much pressure into the system and secondly you'll not end up with a flat tyre on the car.

 

Good luck

[RW1 0]

Due to problems with the board postings. My post above has missing photos....

 

54321 is this

 

[ATTACH=CONFIG]54337[/ATTACH]

 

54317 is this

 

[ATTACH=CONFIG]54341[/ATTACH]

 

54313 is this

 

[ATTACH=CONFIG]54345[/ATTACH]

 

.

[DriverVR6 11]

Wesleyvr6 - Hopefully my first post here may be of help to you. I've owned my VR6 for 12 years and done all of the servicing/repairs myself. I had a similar problem when I overhauled/renewed my braking system (new front calipers, new complete set of braided hoses, new brake proportioning valve, etc) To get rid of the "soft/spongey" brake pedal I bled the system using Eezibleed in the following order: Calipers- Rear Right, Rear Left, Front Right, Front Left. I then bled the brake master cylinder in the old fashioned way by getting a friend to depress the brake pedal. Start the car and use the brakes which should work but with a spongey/soft pedal (NOT ON THE ROAD!! I went up and down my drive for about 1/2 hour). Turn car off and allow the system to settle overnight. Then repeat the bleeding procedure, and hopefully you will get a hard pedal and efficient brakes! I did not touch the bleed nipples on the ABS unit at all. Don't forget to make sure there is load on the rear wheels to ensure the brake proportioning valve allows pressure to the rear calipers.

 

RW1 - Really excellent posts/information. I think I must have just got lucky that the ABS unit did not completely drain of all fluid, as I only found out about that potential problem sometime later!! I agree with you that care is needed when using the Eezibleed equipment and pumping the pedal too much.

[Wesleyvr6 10]

Thanks everyone for all your inputs, going to have another bash tomorrow night and hopefully with success this time, only problem I have is I can't really drive the car as its not mot'd or taxed yet! Just the brakes to sort then that willbe done! I will keep you all updated. Thanks again Wes

[fla 9]

Used an easibleed for my brakes. Made it nice a and easy. I stripped,cleaned and greased the brakes after bleeding each corner in sequence and also sanded the front pads.

But they're still spongey and take a while to stop the car, which is a bit nerve wracking, although its not been driven far yet.

I bled the master cylinder and abs block by just opening the bleed nipples and letting some fluid drain onto a rag. Both were absolutely clean, there were a few bubbles from the mc.

 

Any other suggestions to get proper braking?

Rear brakes when reversing are really great, better than they be ever been but fronts are lousy. I've got 288s BTW.

Thanks

[VW_OwneR_85 1]

when i replaced my rear brake lines they still felt spongey, even with every nipple being bled to perfection! the abs pump was also making a skreetchy noise upon start up so i would hold down the brake pedal frimly upon starting , weather or not that helped push air out of the abs system ? idk, but the spongey feeling and that skreetchy abs noise ended up going on its own...

[Jon_vr6 1]

Yeah mine were sh!t after bleeding 3 times..just drove it carefully and ended up firming up. Thought if they were still bad the mot would flag it up but they came up perfect.