loss of brake fluid

[keefers]

The brake fluid top up reservoir is completly empty. There are no leaks anywhere on the car, so where is the brake fluid going?
Any ideas please.
Keefers

[GDPR]

Either your front pads have worn excessively since you last looked at the fluid, or, more likely, its leaking from the master cylinder into the servo.....

[stagling]

stagling

the previous reply is almost certainly the answer to your broblem suggest an exchange, or new master cylinder to cure fault/

[Staggard]

the previous reply is almost certainly the answer to your broblem suggest an exchange, or new master cylinder to cure fault/

I hope he has it sorted by now as the post was 2012

[SteveD]

I've just had the same situation as keefers; the car has been standing for about a month. Topped up the low half of the master cylinder and went on a 50 mile run this morning and no further loss of brake fluid and no clouds of white smoke.

How do I check for fluid in the servo?

Thanks,

Steve.

[barkerwilliams]

Steve,

Easiest/cheapest way is possible to dip the servo by pulling vacuum hose out and push a long cable tie or wire wrapped tissue/ cotton down to the bottom, or possibly a thin tube whilst sucking and seeing if a fluid comes up the tube - but don't swallow!!!!

Best way might be to buy an endoscope camera - ebay these are ridiculously cheap £5'ish and can be bought to plug into a laptop or directly into an android phone. A great tool for those hellish jobs around the house and car. They usually come with a hook and magnet to help retrieve objects and sometimes a mirror for example for a preliminary look in cylinders at the valve seats.

Alan

Such as:- (no connection)

USB Endoscope Borescope Inspection Tube HD Camera For Android Mobile Phone 5.5mm | eBay

[SteveD]

Thanks Alan, I'll have a look. I wasn't sure about pulling the vacuum hose out.

Steve.

[SteveD]

I pulled the vacuum hose off but my endoscope camera is too big and a cable tie or wire only go in about an inch.

Does the white plastic bit come out?

[MandM]

I think Alan, meant the hose with the non return valve on it

[SteveD]

Please excuse my ignorance but is the white plastic bit the nonreturn valve?
If so how is the valve fixed to the servo and how do I remove it; I don't want to wreck anything.
Steve.

[richardthestag]

I just undo the 2 1/2af nuts and slip the master cylinder forwards. gives access into the servo but also allows you to see if brake fluid is leaking past the pushrod seal.

Why make it complex

[SteveD]

I just undo the 2 1/2af nuts and slip the master cylinder forwards. gives access into the servo but also allows you to see if brake fluid is leaking past the pushrod seal.

Why make it complex

How do you undo the lower of the 2 1/2AF nuts with the MC and Servo in situ?

[JOHNS]

That's what I was wondering because I tried it today to check clearances between servo and cylinder. No room for socket or wrench with front inner wing clash.

[nigele]

I managed it with 1/4” drive socket and universal joint.

Nigel

[richardthestag]

pretty sure I used a ratchet spanner, if not then a 1/4" drive socket. It was not difficult.

By unclipping the brake lines from the bulkhead I was able to shift the master far enough forwards to check for fluid around the push rod. In this case it was bone dry. I later found that the brake fluid was leaking from the flexi/rigid brake union on the o/s/f. the only sign was soft underseal in the area behind the union. no drips, no enormous mess. Must have just been spraying out under braking but not drawing air back in.

I have found that rear wheel cylinders can be a significant cause for brake fluid loss, when the seals fail. normally can see that though dropping off the bottom of the backplate