hydro handbrake help

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luckyrob
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Fri Oct 19, 2012 3:03 pm

Ok so I've got myself a hydro for my E30. I got a Japspeed one as I didn't wanna get a cheapo ebay one that will bend, although if I'm honest I'm not very impressed with the quality of any of it.

Anyway after the unbranded master cylinder that came with it leaked whilst I was bleeding it, I got a Girling one http://www.burtonpower.com/girling-brak ... rk030.html

I fitted it tonight and it bled up straihgt away with no problem. However as soon as I pulled it the rear brakes came on and then stayed on. The only way to release them was to undo the outlet pipe on the master cylinder.

After trying this a few times and double checking that all of my pipes leading to the cylinder were ok, out of desperation I swapped the inlet and outlet pipes over to see what would happen. The result was no rear brakes and no fluid coming out of the rear when I tried to vacuum bleed them.
I then swapped it back to the correct way and it did the same as before.

So it seems like my master cylinder is acting as a one way valve-letting the fluid flow one way but not the other. At least thats the only explanation I can think of.

Any ideas as to why this is happening?
teamalsoran
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Fri Oct 19, 2012 3:32 pm

most likely you havnt got any free play on the pushrod, so the master isnt returning fully, that would make it act like a one way valve
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luckyrob
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Fri Oct 19, 2012 5:34 pm

Sorry if I'm being dumb, but what exactly do you mean by "freeplay"?

When I disconnect the outlet pipe and the pressure lets off then the handbrake moves up and down no problem.

Thanks for the reply
teamalsoran
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Fri Oct 19, 2012 7:34 pm

the handbrake lever must not be exerting pressure on the master cylinder rod when the handbrakes off or it will hold the brake on
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luckyrob
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Sun Oct 28, 2012 2:17 pm

Nice one! When I pressed the footbrake it was pushing the handbrake lever down against the floor....I changed the hole that the master cylinder connected to the lever by so that it sits higher off the floor and it now works! Thanks

However although it locks the wheels up if you turn them by hand .......it doesn't lock the wheels up when driving :(

It seems to be bled up just fine cos the footbrake pedal doesn't feel squishy.....but I do have access to a vacuum bleeder so next weekend I'll give it a try with that.
Any other ideas as to why it might not lock up?
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luckyrob
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Sat Nov 03, 2012 5:14 pm

Well I've just re-bled the system with a vacuum bleeder. Initially it wasn't any different but after a few uses it now locks the rear wheels brilliantly :D
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