firebird mc problems

[psf4x4]

i searched but didn't really give me the answer i needed.

i run a firebird mc with d44's and disk in the rear. plumbed all new lines and no proportoining valve. bench bleed the mc and bleed the hell out the lines.. when i first did the swap the back brakes would lock up and not the front. thought everything was good to go. then started getting in off camber situations and the pedal would go away. so i gravity bleed the brakes. every since then the brakes have sucked ass. bench bleed the mc and they got better. but still not like before. i figure that i still need to lift each tire and bleed as well.

couple of questions.

1. i've got air blowing and sucking between the mc and the booster. will this effect anything. do i need to silicone that up?

2. i've got the front brakes running off the big port in the mc and rear off the small. is that right?





thanks.

[NC Zuk]

Isn't there a hole in the bottom of the master cylinder that needs to be plugged? I know that I read this somewhere

[psf4x4]

thats news to me. any idea where you read that? here are what so i can search it. anybody else heard of this. i'll check when i get home. thanks

[High5]

for the rear brakes locking up and not the front is the lack of the propotioning valve. i did not use the propotioning valve on my new rig and now i can lock up the rears pretty easy and the fronts never do. i plan on adding an adjustible p-valve in the future.

[sh996]

I used the firebird mc too and yes there is a hole in the base of the MC that needs plugged. You can hear the air when you cycle the brake pedal. Plug that up and it will help.

I can lock my front brakes but not the rear....

[psf4x4]

i got home i lifted each tire up and bleed the brakes that way. found a quite a bit of air in the back. still no pedal worth a crap. when i was doing this i noticed a lot of metal shaving in the mc floating around. i would imagine its from the sleeve and spool in the bottom of the mc. i'm going today and getting another mc since there only about 23 bucks. i'll find out where this hole is on the new one before i install it. i also plan on putting rtv around where the mc bolts to the booster. hopefully after all that and a good bleed of everything i'll be good. i'll let ya know. thanks for the help sh996.

thanks for that little bit of info high5 i had no idea why the rear locked up and front didn't

chris

[psf4x4]

they make to master cylinders for the firebird that look the same. one is for disk front and rear drum. they also have one for all 4 disk. i used the one with the drum rear last time. which ones is everybody using. the 4 wheel dick mc sounds like it would work better but is the bore the same as the mc w/ rear drum. anyone?

[High5]

since you are running discs at all 4 corners i'd go with the one that was made for 4 wheel disc. just my op.

[Mike@Accurate]

What year Firebird 4whl disc ? I,ll be looking for a M/C soon. Thanks, MIKE

[sh996]

Mine is out of an '80 firebird.

[psf4x4]

Originally posted by sh996
Mine is out of an '80 firebird.

4wheel disk or front disk rear drum. i just went and order the 4wheel one. if it's not the same bore size as the rear drum then i'll just get that one.

high5............once again

[sh996]

I'm pretty sure its the 4 disk one since I've got disk brakes all the way around, but I honestly can't remember. Good luck.

[psf4x4]

thanks...........i looked up the mc on the napa site. it said the bore size was 1"&1/8. so it will work. i'll find that damn hole and plug it when i get it in the morning. how did you plug it. silicone or what?

[sh996]

I used silicon, but I need to check it to make sure it held. It's a pretty large hole to fill. I think JB Weld or something like it would work better.

[psf4x4]

is it the hole thats right below the bore?

[sh996]

Yep, that's the one. I didn't notice it till after I installed it, so I had to seal it from the outside.