Brakes

[andygill]

Hi

Can anyone help.

Last week my brakes failed. On checking there was no brake fluid and no evidence of a leak. I topped up the reservoir and the brakes now work although you have to press the peddle quite far down. Over the weekend we examined all the brake pads for leaks etc but all seem ok. We thenbleed each wheel and this brought up quite a few air bubbles. The front drivers side has bubbles each time we try to bleed it which seems to suggest a hole somewhere letting in air, however as I say we can't find any evidence of a leak (no brake fluid on the floor and the reservoir is still topped up).

Does anyone have any idea what it could be or what I should look at next.

Thanks
Andy

[ampwhu]

do you have a servo fitted? if so, it's possible that it's going in there and being burnt.

[andygill]

No I don't have a servo fitted.

[chickenjohn]

Unscrew the plate that covers the master cylinder and have a good look down the chassis leg. If there is brake fluid seeping out of the master cylinder then it is on the way out and needs replacing and that is the cause of your lost brake fluid.

[bmcecosse]

There IS a leak if you lost the fluid - so you MUST find it. Did you have all 4 drums off ? You mention 'pads' which suggests disc brakes ? Drum brakes have 'shoes'. As CJ says - it may well be the master cylinder that's leaking - but do run your hand along each and every brake pipe to check for a leak.

[charlie_morris_minor]

i always find kitchen paper for detecting leaks.. as even small amounts appear as very large patches on kitchen paper.

as only the front right has the air bubbles in it, does that not rule out the master cylinder... because if it was at the master cylinder would the air not come out at all slave cylinders?

how long did you pump the brakes for? could it just be that you still have not pushed through all the fluid yet?

[andygill]

how long did you pump the brakes for? could it just be that you still have not pushed through all the fluid yet?

Thanks, I must have pumped the brake at least 20 times

[bmcecosse]

The reason I asked if you had 'discs' is because if you only have the standard fluid reservoir in the master cylinder - it's easy for the disc caliper pistons to move out as the pads wear - and use up all your fluid. So - there may not be a leak - but you have now ingested air into the system - and you need to expel it all to get a good pedal. If using discs - you really should fit a remote mounted reservoir to allow for this fluid 'retention'!