910 Wagon Project

[mindgem]

So after i did some research and found out that a 83 280zx master with a bore diameter of 15/16' would work better i decided i would put the original brakes back on so it will be drivable by next week when i get my license back.
so i fitted my old brakes and bled them all round and felt happy that i was going to have brakes that work properly again, jumped in the car to feel the pedal and found that its lighter than what my clutch is now! check all the brakes and couldnt find any leaks, re bled them again and still nothing. has new brake cylinders in the back and the original brakes which worked prior to me changing to the R31's and now im stumped.
if the master cylinder was faulty would fluid still come out each bled valve? only weird thing is everything worked fine until i put the 31's on then off agian

it does brake the tiniest bit but the pedal is on the floor when it does. no idea what to do now

Edit: oh i forgot to put up a pic of my new t-shirt which just arrived today

[classicdat]

Good to hear there is fluid coming out each corner, I hope this doesn't offend you but just checking, did you get rid of all the air from the bleeders? Sometimes air gets caught in the proportioning valve, in the line to the rear brakes.

[mindgem]

no offense taken lol, i have bled them twice first time around was just a quick normal bleed and make sure the air was out but failing that i re bled and made sure to overkill it and be extra sure i got it all out, was atleast 5-10 bleeds each corner. couldnt see any air. would it make a difference to know that i had taken my master cylinder off and cleaned it out with a rag inside the reservoir? and at one point may have pushed the pedal while the cyl was empty?

that being said i thought that bleeding the brakes would have fixed any issues they might have made

[classicdat]

Take a gander up under the dash and below the cylinder on the fire wall for moisture.
Did you bleed the Master cyl? Did you bleed it with the engine running?

[mindgem]

if you mean bench bleed no i didnt, just put it back on and filled it up again. and it was all bled while the engine was off, cant see any moisture under the cyl or around the brake rod to the firewall

[DJZ]

I think I still have an '83 280ZX master cylinder around if you haven't found one yet.

[mindgem]

I think I still have an '83 280ZX master cylinder around if you haven't found one yet.

Thanks for the offer but i already have one on the way haha, should be here tomorrow. is bench bleeding necessary? or does it just speed up expelling all air from the system?

[DJZ]

I think it's recommended in the factory workshop manual for the 280ZX. Does your master have bleed nipples in the side? You may end up with air in the master that you won't get out by normal bleeding.

[mindgem]

my master has no bleed nipples on it unfortunately and neither does the 280zx one i bought. both have a bolt on the side in between the two outlets though if that means anything

[DJZ]

Pretty sure that screw is just to keep the piston in from memory, it's been a long time since I've had one part. I've got a vacuum bleeder if you have a compressor and want to try it out? Bench bleeding is a pain in the ass and get's quite messy.