Brake probs on 1.9 TDi passat 2003

[Gadge]

Hi,

I recently replaced the front pads on my Passat, as I have done on many many cars before (near side wheel off, calliper off, pads out, push piston back with "G" clamp, reassemble, repeat for off side). Once fitted I started the car to find the brake padal spongy and traveled slowly all the way to the floor. I turned off the engine and brake pedal again travelled slowly (10 secs) to the floor. Jabbing the brake firms them up but if continuous pressure is applied it will soften and travels to the floor.

A VW Tech claimed I had damaged the Master cylinder and that I should have it replaced. I therefore purchased one and, after MUCH ado, fitted it.
A new fault then apeared whereby I could get the break pedal behaving normally with the engine off but as soon as the engine came on the pedal again travelled all the way to the floor.

I then took the car to a garage, who then took it to VW to bleed the remaining air out of the ABS pump - "Special" tool required apparently.

I have just got the car back and although the garage claim the brakes are fine they are pitiful (spongy) compared to what they were, and the pedal now travels 2-3 inches before the brakes come on.

The bill is now at £450 and the problem is still not fixed.

can anyone help?

[adamss24]

Hi, think you dammaged one of the brake piston seals when you wound them back into the caliper and/or you did not have enough fluid in the brake reservoir or the piston was corroded so did not seal properly. I think the master cylinder was replaced for no reason and a simple 20 pounds interface+obd 2 lead of ebay+ vag-com(check Emule, bit torent sites for cracked version of the program !) would have done the same ABS bleeding as the dealer but without the astronomical cost ! Its a good ideea to bleed the brakes again with the help of a friend who knows what to do. Not very difficult but time consumming .For 500 pounds i would have had Brembo/Porsche calipers fitted on me motor !

[Gadge]

Hi Adamss24,

Thanks for the info.

The brake fluid reservoir was half full at the start of the job.
After the master cylinder was replaced the car was bled with a high pressure bleeder prior to VW getting involved and bleeding the ABS pump.

After dismantling the "defective" master cylinder, I agree with you that it was never defective and the original fault must have been elsewhere (£130 quid totally wasted). Anybody need/want a used master cylinder?

You lost me on

a simple 20 pounds interface+obd 2 lead of ebay+ vag-com(check Emule, bit torent sites for cracked version of the program !

The VW guy claimed that he had to use a high pressure bleed valve on the ABS pump to remove the air.

Out of interest what method would you use to bleed a system following a master cylinder change?

Today I have had the car up on stands and checked each corner for leaks and calliper function and all seems OK.

cheers,

Gadge

[adamss24]

See www.rosstech.com and under car procedures, see Abs bleeding. Basically, you connect diagnostic equipment, select ABS module and this will turn the ABS pump on for a couple of sec. several times and thats it, the pump will expell out the air by itself ! Follow the website and look for the Support link.

[Teutonic_Tamer]

See www.rosstech.com and under car procedures, see Abs bleeding. Basically, you connect diagnostic equipment, select ABS module and this will turn the ABS pump on for a couple of sec. several times and thats it, the pump will expell out the air by itself ! Follow the website and look for the Support link.

This is not necessary on Bosch 5.7 ABS/ESP systems, which the Passat has. Don't let a dealer try to baffle you with this piffle either.

Your ABS modulator will be activated, and therefore fluid pumped, every time the traction control, ABS, ESP, or electronic diff lock works. To make sure all channels of the system are activated, find a wet grassy field somewhere and activate the ABS repeatedly a few times, by braking hard until the buzzing pedal is felt.

Rgds

[Teutonic_Tamer]

Hi,

I recently replaced the front pads on my Passat, as I have done on many many cars before (near side wheel off, calliper off, pads out, push piston back with "G" clamp, reassemble, repeat for off side). Once fitted I started the car to find the brake padal spongy and traveled slowly all the way to the floor. I turned off the engine and brake pedal again travelled slowly (10 secs) to the floor. Jabbing the brake firms them up but if continuous pressure is applied it will soften and travels to the floor.

You might want to have a look at my museings at post#5 in the following thread: https://www.vwaudiforum.co.uk/forum/s...ead.php?t=3877

Rgds

[Gadge]

Hi T-Tamer,

Thanx for the info,

It looks like we had exactly the same problem after the pad change.

I'll follow this up with a VW specialist in the next few days and let you know how I get on.

Thanx again,

Gadge

[Teutonic_Tamer]

Hi Gadge

Any updates?

Rgds