Leaking master cylinder?

b2tf · 17-09-2011, 07:01 PM

Some investigation as to where the hell my brake fluid is going has led me to find a nice slimy trail going down from under the master cylinder onto the chassis rail. I havent pulled on apart before so I'm just wondering if it is a) a common problem and b) what the best option (repair or replace) is to fix it. Any ideas?

galaxy xr8 · 17-09-2011, 07:08 PM

Are they still a BPR master cylinder ?.
I suspose it depend's on what it cost to repair compared to buying a new/overhauled one, there really isn't to much involved in a master cylinder, might just be a leaking piston ?, therefore fitting a kit through it.

all4fordau · 17-09-2011, 07:34 PM

I had similar issues with mine about 3 months ago. After trial and error, and also after purchasing a new master cylinder, I discovered that there was nothing wrong with my master cylinder. Stupid me, I did not replace the cover correctly when I last topped up the fluid, and jammed the rubbery thing inside, between the body of the fluid container and the lid, resulting in exactly the same symptoms you mentioned. It is worth checking and may save you a small fortune????? Let us know how you get on.

b2tf · 17-09-2011, 08:00 PM

I havent noticed a difference in braking feel and I only topped it up about a fortnight ago. Im fairly sure its not just the lid incorrectly fitted but will check it again. The trail of fluid seems to be coming from the back of the unit and going down onto the rail, I might hose it off and then see if it does it again.

FGII-XR6 · 17-09-2011, 08:04 PM

if you do decide to put a kit through it make sure you hone the bore first then a thorough clean with metho to remove residue without leaving oil or water behind then lube with clean brake fluid before assembly
I can't stress the cleaning enough there can be no dirt oil or water left in the system or it will fail quickly

**GasoLane** · 17-09-2011, 09:14 PM

Oh-uh...there goes the paint.
This is soon followed by here comes the rust.

cedric · 19-09-2011, 05:27 PM

i had to do mine a couple of months ago for same reason, au3 xr8

b2tf · 19-09-2011, 05:54 PM

I got in and cleaned it all up over the weekend, bit annoyed as it has taken some of the paint off the chassis rail but nothing a quick hit of black spraypaint wont fix. I will wait and see if it loses any more but if it does I reckon I will replace the entire thing.

Does anybody know if the AU has a generic (ie non engine or model specific) master cylinder? Im assuming it wouldnt.

**Mechan1k** · 19-09-2011, 05:56 PM

i just had mine replaced in the end ... for time really.
One way of telling that it's gone is ... when stopped ... push down the brake pedal firmly ... if it sinks slowly to the floor under pressure then you definitely have an issue with it.

FGII-XR6 · 19-09-2011, 06:02 PM

there are various master cylinders to suit different body and mechanical configurations including different between traction / non traction, wagon , ute, sedan. series 1 and series 2/3 so to maintain the correct brake bias you need the reigh cylinder

Quote:

Originally Posted by b2tf

I got in and cleaned it all up over the weekend, bit annoyed as it has taken some of the paint off the chassis rail but nothing a quick hit of black spraypaint wont fix. I will wait and see if it loses any more but if it does I reckon I will replace the entire thing.

Does anybody know if the AU has a generic (ie non engine or model specific) master cylinder? Im assuming it wouldnt.

mik · 20-09-2011, 01:21 AM

from memory they are about $200 from ford, if you ring around a few brake places you may find one a bit cheaper.