fitted new pads and discs now rubbish brake and clutch pedal

[deac666]

Hi all, I fitted new discs and pads to my 2002 a3 tqs today. been trying to bleed the brakes through and have a rubbish pedal now. I left the front calipers of for a day whilst cleaning them up. this made the system lose loads of fluid, I connected my gunson bleeder and it fired almost a whole bottle into the system. so I then set about bleeding the brakes pas rear, driver rear, pas front, driver front, clutch slave, then master cylinder.

Took the car for a drive and lost clutch pedal totally and brake pedal travel was a long way don't and brakes were not that sharp (I understand new pads and discs will affect this) So I bled everything through again but turned the engine on before doing the clutch slave and master cylinder loads of air came out of the clutch slave.

Took car out again out again and the clutch pedal was the best its been but then got worse and worse. brakes stayed about the same.

The clutch was not the best to begin with and I have previously lost the pedal on the drive home from picking it up. with the ignition off the brake pedal goes hard but as soon as you start the car the pedal drops a fair way to the floor. braking hard whilst driving you can feel the abs starting to kick in. checking the fluid level there is no noticeable drop

So any ideas on the problem, am I doing something wrong or is there a part at fault, forgot to say that the bite point of the clutch is low down in the pedal stroke.

any help advice would be a big help

Cheers jon

 

[AJC]

Hi Jon, welcome to the forum.

Sounds like you may have been unlucky and blown the seals in either the master cylinder or slave cylinder? You've bled the system correctly using a bleeding kit (pushing the pedal manually can cause problems) but sometimes when replacing the old fluid in the clutch lines this can happen.... same thing happened to me (clutch pedal on the floor) and culprit was the master cylinder.... nothing you can do to prevent it really, just bad luck.

Replacing either part is a bit of a pain.....master cylinder is harder to get at on RHD cars and slave cylinder is a gearbox out job....Audi quoted me just 1hr to replace a master cylinder!! They also offered a significant discount to owners of older cars and guaranteed the price...didn't know of anyone else who could change a MC in 1 hr so I went with them.....job actually took 5 hrs (1hr was for LHD cars) but they honoured the price quoted....cost me £90 labour and £80 for the MC and part is guaranteed by Audi for 2yrs.

Hope that helps?

Andy

 

[hoffmanvp3]

Sounds like there's still air in the system. have you tried using a vacuum pump?
don't know how you did your brakes but whenever I change the pads/disc I just put a hose on the callipers bleed nipple and open the bleed nipple and move the piston back till it nogo's. Then close the bleed nipple and open the master cylinder and pump the brakes and top up the cylinder where necessary

 

[Lewis583]

Have you bled the ABS pump? If you have totally drained the system, I bet there will be a pocket of air in the ABS contributing to the poor pedal feel.

You can put the ABS pump into a bleed procedure with a capable diagnostic machine. VCDS being the most accessible to enthusiasts and is a very good price. If you are interested in buying a VCDS cable yourself then drop a pm to Nige/NHN LINK TO NHN PROFILE Having bought my cable from him, I can vouch for him :icon_thumright: As can countless others on the forum.

Failing that, you can view the VCDS Users map, in the VCDS section, and see if there is anyone local to you who is willing to give up some of their time to help you. Though the map currently appears to be not working for me, same for anyone else?

 

[deac666]

thanks for the replys. there is no fluid leek that I can see anywhere. so would that mean that seals could be fine?? just meaning that there is air in the system somewhere??

lewis as I left the calipers off on the front and forgot to clamp the lines the system drained a fair amount of fluid could this have drained as far as the abs pump causing an air bubble/ lock.

do you have to buy the software to be able to do this abs bleed procedure or can you download it and just buy the cable???

 

[Lewis583]

When you buy it, you are paying for the cable and a full license including support from Ross-tech. The software is free to download from the Ross-tech site.

There are fake VCDS cables available on eBay which work with out of date Ross-tech software which are a lot cheaper, but whether the fakes offer the option of ABS bleeding procedure I can't tell you. Maybe someone who owns a fake can chime in?

Yes, the master cylinder supplies fluid/braking pressure to the ABS pump solenoid block, which via channels inside the pump, is distributed around the braking system.

 

[deac666]

would this also affect the clutch if there is a pocket of air in the abs pump??

 

[AJC]

thanks for the replys. there is no fluid leek that I can see anywhere. so would that mean that seals could be fine?? just meaning that there is air in the system somewhere???

If the seals have gone there will be no fluid leak as it will be retained in the system....the piston simply won't be able to exert any pressure in the system. If you haven't bled the clutch for a while (easily overlooked) you normally get some pretty black fluid which when replaced can cause the seals to go. I am suggesting your clutch master cylinder may have gone and not your brake master cylinder.

 

[deac666]

Will the clutch slave going affect the brakes though??

im going to bleed the whole lot one more time today how much fluid through each line would people think would be enough to flush each line??

Cheers jon