BadBoy03

A Mk1 Is For Life, Not Just For Fun
Sep 6, 2016
859
712
Somerset
Hi all.
Following a stint in the garage for braking diagnosis, I've been advised that it 'could' be the abs pump.
The symptoms are:- Front brakes bind on when warming up (within 10-15 mins they are seizing on), the brake pedal is firm when ignition on & before long, it's almost rock hard to press.
I had new brake lines, braided hoses & front pads replaced last year, leaving me with an un-driveable car.
I believe it's fully down to fluid pressure not returning, & all search results point towards a master cylinder compensation-port issue so I'm not sure about the conclusion. I feel like I can't get these tests done, just get possible ideas. The braking system was immaculate before the work, flawless braking, so could the abs pump be responsible if it was fine before?
I am more than happy to have a professional opinion, but it all seems like guess work. The garage said it wouldn't flag up on a diagnostic, it's too old, but I find this unusual (am I wrong?).
If anyone could help me in any way, is be so grateful. I don't want to fork out for an expensive pump, only to find that it's made no difference at all. Also, doesn't an abs pump need to be programmed to the car?
I'm very confused, so if you folks have any advice or questions, please throw them at me. Thank you!
 
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It seems a vaccum line problem. Try this: with your engine off brake 4 to 5 times and probably your brake pedal will get hard as a rock - and with your foot still braking the car, START the engine and check if the brake pedal goes down a little. If it doesn't softens a little then it would be the servo brake = vacuum booster.
 
Check the vaccum line from the servo brake until the intake manifold. Also check on that hose the anti-return valve. It has to be pretty well tight with no air leaks and no damage or fenders. Also check if the valve is on the correct direction (it is a one way valve).
 
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Hi all.
Following a stint in the garage for braking diagnosis, I've been advised that it 'could' be the abs pump.
The symptoms are:- Front brakes bind on when warming up (within 10-15 mins they are seizing on), the brake pedal is firm when ignition on & before long, it's almost rock hard to press.
I had new brake lines, braided hoses & front pads replaced last year, leaving me with an un-driveable car.
I believe it's fully down to fluid pressure not returning, & all search results point towards a master cylinder compensation-port issue so I'm not sure about the conclusion. I feel like I can't get these tests done, just get possible ideas. The braking system was immaculate before the work, flawless braking, so could the abs pump be responsible if it was fine before?
I am more than happy to have a professional opinion, but it all seems like guess work. The garage said it wouldn't flag up on a diagnostic, it's too old, but I find this unusual (am I wrong?).
If anyone could help me in any way, is be so grateful. I don't want to fork out for an expensive pump, only to find that it's made no difference at all. Also, doesn't an abs pump need to be programmed to the car?
I'm very confused, so if you folks have any advice or questions, please throw them at me. Thank you!
I dont really know what the issue is here, but its been said if the brakes are bled by pumping the pedal itll ruin the master. The garage you're speaking too seems to be fobbing you off saying its too old to flag on the ECU, that is not something that happens. . .
 
Check the vaccum line from the servo brake until the intake manifold. Also check on that hose the anti-return valve. It has to be pretty well tight with no air leaks and no damage or fenders. Also check if the valve is on the correct direction (it is a one way valve).
Thanks mate, I really appreciate it!
Unfortunately the car is still laid up at the garage, hoping to bring it back home at the end of the week. I'm not having any work done because I don't trust it.
I'll have a go when I get it home. Thanks again 👍
 
I dont really know what the issue is here, but its been said if the brakes are bled by pumping the pedal itll ruin the master. The garage you're speaking too seems to be fobbing you off saying its too old to flag on the ECU, that is not something that happens. . .
I think they are mate, just giving me BS.
I've now booked it in with my local VAG garage on 22nd. It's driving me crazy, can't get anyone to be thorough & honest with me.
 
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Hey mate, sorry to hear about the issues. I don't really see any way that those symptoms could be the ABS pump, plus i know the cars are getting on, but the ABS pumps are usually pretty reliable. The chances of it developing a fault when they have just done your brakes is highly unlikely.

I agree with what the other lads said, sounds like either a problem with the servo side of things, or they damaged the master cylinder trying to bleed the brakes. From the way it binds after 10 mins that does sound like classic compensation port symptoms. If they were pumping the brakes hard then it could have caused some debris to have come loose and block the compensation port.

The ABS pump can be bled with VCDS, although from the symptoms i can't see that helping, but if they haven't done that, then it may be worth a go to see if it helps in any way. If it does get to the point of replacing the pump, then yes it has to be coded to the car. You will need to write down the long coding from your existing module and transfer it to the new one.
 
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Hey mate, sorry to hear about the issues. I don't really see any way that those symptoms could be the ABS pump, plus i know the cars are getting on, but the ABS pumps are usually pretty reliable. The chances of it developing a fault when they have just done your brakes is highly unlikely.

I agree with what the other lads said, sounds like either a problem with the servo side of things, or they damaged the master cylinder trying to bleed the brakes. From the way it binds after 10 mins that does sound like classic compensation port symptoms. If they were pumping the brakes hard then it could have caused some debris to have come loose and block the compensation port.

The ABS pump can be bled with VCDS, although from the symptoms i can't see that helping, but if they haven't done that, then it may be worth a go to see if it helps in any way. If it does get to the point of replacing the pump, then yes it has to be coded to the car. You will need to write down the long coding from your existing module and transfer it to the new one.
Thanks mate, I really appreciate your help.
I think it's a master cylinder issue & I put this to the original garage last year, trying to make sense of how they'd bled it & the damage that might have been done. Unfortunately it got abusive when I complained about the result (two failed attempts to get home, after 'they'd fixed it').
I honestly don't mind having to get something sorted, but when I get abuse for protecting my property, fed endless bs & threatened with 'i know where you live', it turns it into a saga that I don't need. I only got my car back last year when I tricked the dude into taking it for a quick test drive & I took it home with seized brakes.
I'm collecting my car tomorrow & even though these dudes had done a good job on my Ibiza previously, this is not the garage for my Leon. It's going to a vag garage on 22nd & once I've got it home I can tinker with it a bit.
I am very much a novice with cars, but enjoy working on it, however with the braking system, I just want someone competent to make it safe & ready for MOT. 😣
 
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Thanks mate, I really appreciate your help.
I think it's a master cylinder issue & I put this to the original garage last year, trying to make sense of how they'd bled it & the damage that might have been done. Unfortunately it got abusive when I complained about the result (two failed attempts to get home, after 'they'd fixed it').
I honestly don't mind having to get something sorted, but when I get abuse for protecting my property, fed endless bs & threatened with 'i know where you live', it turns it into a saga that I don't need. I only got my car back last year when I tricked the dude into taking it for a quick test drive & I took it home with seized brakes.
I'm collecting my car tomorrow & even though these dudes had done a good job on my Ibiza previously, this is not the garage for my Leon. It's going to a vag garage on 22nd & once I've got it home I can tinker with it a bit.
I am very much a novice with cars, but enjoy working on it, however with the braking system, I just want someone competent to make it safe & ready for MOT. 😣

Yeah i've been there before when my brother had a dispute with a dodgy garage/car dealer. Went down there to try and mediate a solution and things escalated and one of the mechanics implied he was going to stab me with a screwdriver lol.

Hopefully the VAG garage can diagnose the problem easy enough. Master cylinders are pretty cheap, so if everything else they did looks ok, then probably the best course of action would be to replace it.