i cant get my back brakes working,

they are discs

i had the calipers off and put new lines on, bleed it about 4 times now and still nothing

what could it be?

when we bleed fluid comes out and there is no air in them, it goes through a decent amount of fluid so it seems to be flowing quite well,

there is no leaks anywhere

but when you try to use the brakes there is only slight pressure applying the brakes, and there is very little pedal fell until the front brakes start working

two things i can think of, mater cylinder is stuffed in some way???

or when i used the clamp to push the cylinders back the pistons stuck, but then the pedal would be really firm yes?

oh, and maybe there is a kink in the line from the bending that was done, but again i would have strong pedal fell if this was the case i think


what could it be????

im pretty sure im gonna be replacing the master but can anyone think of any other prob i may have???

Possibly master cylinder. Did you remove the rubber valve and spring out of the rear brake line at the master cylinder? You need to remove the line, and then pull out the conical bit with a hole down the centre, and behind that the rubber/spring valve is found.

If that doesn't work, I'd try another master cylinder off a 180B/240K etc..If it still didn't work, then I'd go and find a master cylinder that came off a 4 wheel disc model car.

Chris.

what master cylinder is pictured in that link?

i noticed its a 7/8 bore which is what i plan to use... what car is it originally from??

180B I think. It was my old one procurred 10 years ago, so I'm not sure. Sorry.

hi another thing to check,make sure the bleed nipples are at the top side of the caliper,you may just have them on the wrong sides.air is lighter than brake fluid and will sit at the top of the caliper,giving u a bad pedal.just a thought.

try using a 200sx 1980-84 master swap in your pushrod and the bias will be right for disks on the back. the stock m/c is biased for drums and will not provide enoug fluid to operate the rear disks correctly. I have done the swap severall times on 510(1600)s and ran into the same problem, once I figured out the fix I had no problems out breaking corvettes and supras (I was going 40-50mph slower admittedly)

yeah, thanks for the help,

one thing i didn't say was this setup was working before i put the new lines in, and it had perfect bias (a little more on the back)

i have a 180b master in it now, have to change it i guess..

Is the 200SX the equivalent of the 810 (the Australian 200B)?

They never came with 4wheel discs..not that I know of.

I think it's the S12 Silvia (Gazelle) we are talking about in relation to the 80-84 200SX.

Chris

i have the 180b master, and dont know if that thingy was taken out but it worked before and had perfect bias