Brakes/ABS Problems

[Roddy the Dog]

Here we go

We have been running this Transit minibus for the better part of 2 years and the brakes have never been right on it,always feels like it has air in the system and you have to pump the pedal just once to get a good brake.
I replaced a few brake pipes for last years MOT and stripped all the brakes off it just to be sure nothing was seized or out of adjustment no probs there,bled the system manually,then with a pressure bleeder but just the same crap pedal.
Took it into work today,called at the parts shop on the way to get a master cylinder for it,but they have no listing for an R reg transit with ABS,it seems to be a bit of an oddball being a Ford factory built bus,however I took the one they had that matched the one fitted and went to work to fit it,only when I had stripped the old one off did I notice the only difference was the size of the ports the brake pipes go into.

So nothing ventured etc I stripped the old MC but could only manage to remove the front [rear] piston assy,cleaned it all up and shoved it back on,bled it as far as the ABS unit and took it up the road,top banana,pedal at the top and stops on a sixpence,hit the brake hard enough and the ABS cuts in

Happy as a sandboy I set off on the 20 mile journey home only to get about 2 miles before the front brakes are binding for England,managed to limp far enough to a friends house to blag a 13 mill spanner and crack the pipes on the MC and let the pressure off and drive home on the handbrake only,also pulled the fuse on the ABS just for if!

What do you folks reckon to this problem?

Cheers Rod

[rover]

I would say its probably just a case of re adjusting the back brakes and or handbrake cable, if the MC was crappy before and now you have fixed it then the pressure needs somewhere to go.... Thats not explained very well is it?? If you just flick the adjusters down on the back brakes and then pump the pedal to adjust them back up you probably wont have the problem again, it was probably just a case of the fluid expanding now that you have repaired the MC...

I'm gona put this beer down now


Rover.

[Nighthawk]

My guess is that you've killed the master cylinder if the brakes are binding since you stripped it.

Did you put new seals on the piston you got out? if not they'll have swelled as soon as they made contact with the air.

[Roddy the Dog]

Hi again
Got a new MC,had to come via a Ford dealer £120 genuine Bosch part,stuck it on tonight,outside the house in a blizzard!
My wife is desperate for her bus back so it had to be done

Anyhow we are back to square one...crap pedal

I am now considering ripping out the ABS and piping it up like a stock Transit,nice and simple,apart from the mass of wiring I will have left over.
A job for another day I think!

Rod

[Nighthawk]

If i'm reading you right, your saying you have a poor pedal feel but the brake performance is Ok.

Transits after 97 had a softer pedal feel by design, it feels like a long pedal travel but it doesn't go to the floor.

When subjected to a brake test, it'll pass the MOT spec with ease and on the readout you can watch the brakes react pretty much as soon as the pedal is touched.

Also, dealers had the facility to perform a service bleed on the ABS using wds, that runs the ABS pump each time a bleed nipple is opened to ensure that no air has been trapped in the modulator.

hope some of that helps, aside from the above, make sure the wheel bearings and brake adjusters are ok as they can both affect pedal feel.