Brake master cylinder pressure releif bolt?? *Kinda urgent*

[AE86slut]

So I'm trying to figure out why my rear brakes are locked on, and inadvertently undid this mysterious bolt (10mm head) on the side of the master cylinder. It's situated in the area where the feed from the reservoir enters the cylinder from the top, and seems to be some kind of stopper or relief valve. I get the feeling that this may be my problem as it appears to be possibly preventing pressure from the rears from returning to the reservoir.
Also, if you tighten it at a certain point in the pedal's travel, the pedal will only go half way down before it stops, although it's not being stopped by hydraulic pressure, you can feel it's something solid preventing it from going further. Hopefully this is enough info. Can someone help me out?

Cheers,

Jeremy.

[TurboRA28]

I thought that was just to bleed the master cylinder.. But might be wrong there.

Where the pipe actually screws into the master cylinder for the rear brake lines, if you undo that assembly there is often a valve in there.

[ganador]

hey i was doing this with my hilux not so long ago too, i thought it was brocken but the shaft on the inside get pushed forwards the the 10mm gets done up and acks like a stop if you know what i mean. thats what i did anyway and my brakes are fine.

[thechuckster]

the bolt on the side of the cylinder is used for assembly/dissaembly of the piston - it's called the 'piston stopper'. It prevents the front piston from easacping from the MC when you pull the MC apart.

My local copy of the TSRM has a pic at this URL:
http://www.cygnusx1.net/supra/librar...br/BR_009.html

but the current TSRM on cygnusx1 is running massively slowly at the moment - if/when it comes back you'll be able to see/read what it does. By playing with it without access to the rear of the MC your effectively jamming the front piston.

[AE86slut]

Thanks for the replies fellas. Just got the rear calipers back on and took it for a drive and although the pads won't do a whole lot until they are hot, it still feels like only the rear brakes are working and the front is getting nothing. I guess I'll pull the MC off tomorrow and see if I can fix the prob.The biggest PITA about this whole thing is that with everything I do I have to then go and bleed the master, bleed the bias valve, bleed the handbrake master, then bleed the calipers. It's doing my head in! Rears also seem to be still locking on. Maybe I'll sell my now blue rear rotors to some ricer as the latest craze.
Cars FTL...

[Sam_Q]

I have a standard master cylender that you can have for $40, that any good to you?

[AE86slut]

I have a standard master cylender that you can have for $40, that any good to you?

Hey Sam,

Thanks for the offer mate, but if I'm going to change MCs I'll go for something a bit bigger such as an S13 or R32 one.

Cheers,

Jeremy.

[takai]

I have a Patrol MC which i will be selling soon if you are after that, 17/16ths.

[Sam_Q]

yeah no problem, try looking at hilux too if your after a 15/16 thats soposedly what mine is