Clutch master cylinder

[max]

Hi guys, had a quick look at my clutch problem. Basically the clutch only works if you pump it.
So, I thought I would bleed the system, and what came out was black!? I used an Easybleed, so the fresh clean fluid came through after a few seconds.
I had a second hand master fitted and I'm guessing its knackered?! There are no signs of leakage, so could it be failing internally? Are new ones pricey?
Cheers, Max

[polov8]

My master cylinder is weeping ever so slowly, I managed to find a replacement on ebay having drawn a blank at BMW, Euro car parts, GSF etc. It was £39 which isn't too bad. I still have to get round to fitting it.

[drjim]

Have you changed the hose?

[Jeroen]

If you don't have any leaks I guess it's leaking internally indeed so it may be that instead of pushing the fluid to the slave, the fluid is returned into the tank (only small quantities anyway). Never seen that before, usually they leak externally but you never know. There are rebuild kits for them, just make sure to hone the cylinder, also see in this topic where we're discussing overhauling the brake master: http://www.bmwe21.net/forum/viewtopic.p ... &start=225

You could also have a leak on the slave that you will probably only see when you remove the slave from the bell housing. Usually these leak into the bell housing so it may take a while before you start to see. However, with black fluid coming out of the slave bleed plug it is not likely that the slave is leaking, then you'd have fresh fluid there.

[max]

Thanks for the replies guys.
I've been on the phone trying to get him of a master cylinder, with on joy. GSF gave me a part number of PND 116, the one I found on eBay was PND 111, does any one know if they are the same?
It shouldn't be the slave as I fitted a new one not long after I bought the car.

[drjim]

IS the pedal hard when you pump it? I had this on my original E21in Australia and many years later I have decided it was the hose. They perish internally and intermittently block.

[max]

No the pedal is soft. I might replace the hose while I'm at it though?!
Just ordered a M/C from an eBay shop. Hope it's the right one.

[max]

I'm now looking for a hose...with no joy! Does an e30obe fit?

[drjim]

It's a standard bit of hose, think the one on my baur is actually a front brake hose.

[max]

Quick up date.
Ordered a new master from an eBay shop. Came pretty quick. The hose looks in good nick so didn't get a new one.
I removed the old master to it at first looked ok but when I putted the rubber back it was full of fluid! So there it is. I fitted the new one, but haven't tried it yet because I managed to crack the thermostat housing! One step forward....

[Jeroen]

You pushed the clutch pedal that far huh?

[max]

Haha! No I snapped the bolts replacing the thermostat, drilled out the snapped bolts bit the tread was knackered, drilled and tapped a new tread but it didn't leave enough material on the lug, and it snapped of!
Ordered a second hand one off eBay, from an E30. Need to give the system a ruddy good flush.
It might be on the road again by next weekend?!

[polov8]

If the one you got on ebay is the same as this one, then I can report that it fits fine, with two minor issues.




Firstly, the original had the outlet on the end of the master cylinder, where as this one is on the side, but there's enough pipe to carefully bend it round and screw it in but....

Secondly, I found that it then interfered with the vacuum advance on the distributor, but by removing that, and turning it one tooth round on it's gear (having marked the position of the rotor arm relative to the body first!) it all went back together fine. After bleeding, the clutch works spot on now, and the new carpet is at no risk of damage, unlike the old one, which should've been blue, but was a funky shade of orange and brown due to the brake fluid.

[max]

Thanks. That's what mine looked like. All sorted an wiring now!