New Brake Pipes - Brake Pedal Soft

[rustychain]

Hi

 

I replaced all the brake pipes on my '99 Tdi the other week.

 

I'm now struggling to get the brakes to work properly, despite bleeding them several times. The pedal goes spongy after a while and even when it stiffens up, the stopping power isn't like it was before.

 

The car got through it's MOT, but the tester mentioned the brake pedal was spongy.

 

I wonder if I've managed to get air in the ABS block? If I have, any suggestions on how to correct this please without taking the car to a Ford main dealer (as suggested in the Haynes manual).

 

For info I've not replaced anything else eg pads etc (that's next weeks job!).

 

Thanks

Sean

[seatkid]

Could be air in the ABS block as you say. Possibly crack the unions on the ABS block one by one while someone has some pressure on the pedal?

 

Also maybe try forcing the ABS to operate (emergency skid - somewhere safe though!) to purge it out the block and then rebleed..

 

I checked the TIS cd and even if the abs unit is replaced, it says conventional bleeding only is necessary, have you pumped plently of new fluid through? (Several strokes of the pedal, closing the bleed valve every time you (slowly) release the pedal)

Edited April 15, 2013 by seatkid

[nicebutdim]

Kwik fit are really helpful with brake bleeding. I don't normally take the car anywhere to have any work done but I struggled getting a small amount of air out of the system. Took it there and for a small outlay they bled it perfectly. 

[rustychain]

Thanks for the responses.

 

I'll try flushing through some more fluid in the first instance to see if that works - might be all it needs.

 

I would try activating the ABS, but the ABS light came on out of nowhere after the car had been sat on the drive for the last two weeks. Haven't started working on that problem yet.

 

The car is 12+ years old so I shouldn't complain, but it seems to be needing lots of TLC at the moment.....

[f0ster]

it might be the master cyl failing, when I have this asort of problem I back bleed the system, get a good oil squirty type oil can full of fluid, put on it the bleed nipple with hose and pump away till your harts content, this method is very good small volume systems as well like motor bikes,

[seatkid]

it might be the master cyl failing, when I have this asort of problem I back bleed the system, get a good oil squirty type oil can full of fluid, put on it the bleed nipple with hose and pump away till your harts content, this method is very good small volume systems as well like motor bikes,

 

Back bleeding should never be done as it can push debris into the abs block and ruin it.