Brake Problem

[jonmadrid]

just changed all pads on galaxy 2003 diesel , but now the brake pedal almost goes to floor , I have bled all corners but no difference, when you pump the pedal up and push the pedal fades away when engine running, when engine off pedal pumps up hard , can anyone advise please thanks Jon

[RADIOTWO]

just changed all pads on galaxy 2003 diesel , but now the brake pedal almost goes to floor , I have bled all corners but no difference, when you pump the pedal up and push the pedal fades away when engine running, when engine off pedal pumps up hard , can anyone advise please thanks Jon

 

Hi Jon

 

First of all, why did you need to bleed all four corners ?

 

but if you have replaced all pads, it will take a few miles to bed in

 

Radiotwo

[NikpV]

assuming that this a 2003 so a mk2 - post moved to technical form from mk3

[Saif Rehman]

I seem to recall that my older brother had a similar problem you are encountering in his 2001 mark 2 Ghia 1.9tdi - it turned out that the guy (cowboy!) who fitted the pads, forced the pistons back to hard and quickly causing the seals in the master cylinder to invert. The result was the same as yours and he had to get frauds to fit a new cylinder.

 

So can i ask - How did you push the pistons back in the caliper?

[Bigjeeze]

I would be interested to hear the solution to this one. I have often read that pushing the piston back in too far or too fast, causes the seals to invert - but if that is the case why does the pedal pump up fine when the engine isn't running? Surely the problem would be there regardless of the engine running as it has an hydraulic issue?

 

Could it be something to with the ABS system? maybe it has air in it or a valve in that is not seated properly?

[sparky Paul]

I would be interested to hear the solution to this one. I have often read that pushing the piston back in too far or too fast, causes the seals to invert - but if that is the case why does the pedal pump up fine when the engine isn't running? Surely the problem would be there regardless of the engine running as it has an hydraulic issue?

 

Could it be something to with the ABS system? maybe it has air in it or a valve in that is not seated properly?

 

If the engine isn't running, it's hard to shift anything as the hydraulic pump for the abs system stops.

 

If the symptom is a soft pedal, and there being much more pedal travel when the engine is running, it sounds like something is being compressed - either something is not fitted in the caliper properly and is springing, or there's air in the system. Also check the flexible hoses carefully whilst someone pushes the brake pedal, especially if they've been clamped when pushing the pistons back in.

 

However, if you are saying that you can pump the pedal until it is hard, then it subsequently sinks absolutely to the to the floor, that indicates fluid is passing a seal which could well be a damaged or contaminated, as the other guys say. If fluid has been pushed back into the abs hydraulic unit when changing the pads, it could be a distinct possibility.

 

Check the obvious bits first, where the flexible pipes have been clamped, and that the calipers are correctly assembled.

Edited October 14, 2007 by sparky Paul