[Big Al]

Just something to test or look out for. brakes work fine and not spongy. Start engine and press firmly but not too hard on the brake pedal, does the pedal creep slowly down to the floor release pedal and it returns to working normally. this happens when the seal passes in the master cylinder, normally faulty rubber seal or scratched or corrosion on cylinder bore, no leaks it is just one of the two pressurising seals passing back to the tank. Do not know how long mine has been faulty for maybe from new. Fitting a new one at weekend, dealership supply only £140. And flushing system with fresh fluid.

 

[K.L.Richards]

Cheers for the info Big Al...


Is this a test that would be carreid out during an MOT. Seems like it is something you wouldn't normally do, so how did you suspect you had a fault.



Fortunatly, I have a local garage who is 120% dependable and doesn't take the p!ss. Really trust the garage. They did my MOT and didn't report anything. So just trying to work out wether this is something they would have checked for, or whether I should be looking for a tell tale sign.



Cheers...

 

[Big Al]

Mine past the mot fine, braking figures on the rolling road where fine. [do not believe they check further than rolling road test regarding the pedal, unless it shot down quickly]It showed up while in drive with the auto holding on the foot brakeat some traffic lights, lights took ages to change while sat there realised the pedal was going lower and lower. when I got home tried it again and the pedal kept going till it got to the floor.if you lift off and re-apply the pedal returns to the top, but not very good when towing a caravan down a long decent. There is quite a bit of data about the problem on the net but usually on old units this is why I wonder if mine has been a faulty unit from new but never noticed. There is no after market seal kits made yet or even complete units so had to get one from the dealers, when I fit the new one I will strip the old one to see where the problem lies.

 

[K.L.Richards]

Thanks for the update.


I'll do a check on mine. Mine is not an auto, but I'll give it a test as you suggested.



Anything you do find out will be welcomed here as always....

 

[Big Al]

Fitted master cylinder OK and bled the lines, but need to bleed the ABS unit. Require help from any of you out there with a manual, firstly does it tell you which unitthe captiva uses, is it Bosh and if so which model, also is there a bleed on it or do you need a scan tool to cycle the valves any information would be appreciated. Al.