Camaro rear disc brake conversion

[Shon]

OK, I am fed up. I have the Camaro Rear disc brake brackets with the LT1 calipers and Impala rotors.
Truck is original 71 with Disc/Drum set up.
I can not get both sides to bleed. The driver side will spit out a nice stream of fluid but holding the brake pedal down it doesn't clamp enough to keep the rotor from turning. The other side just dribbles out.

What do I need? I am guessing I need a different combination valve (prop valve as some call them). Do I need a different Master Cylinder? Was hoping I could get this to work with what I have but I am doubting that now....

I have this set up currently:
http://www.piratejack.net/index.php?...emart&Itemid=6

[RodnRudy]

You need a disc/disc master cylinder and proportioning valve to make your set up work.

[Shon]

any recommendations on part numbers?

[SierraMtns]

Can you post a picture to see what you are working with?

What size bore is your master? You might need a new one. I am running a 1" bore with disc/drum. I hear that some guys run a 7/8" bore with disc/disc. I know if you call Wilwood they will tell you need a 15/16" with disc/disc.

Did you run new lines? 3/16 or stock 1/4"?

http://www.piratejack.net/index.php?...emart&Itemid=6

http://www.piratejack.net/index.php?...emart&Itemid=6

[Joe Pass]

That master cylinder has no residual valves in it. If it's like my disc setup I had to use the residual safety valves (2lb) front and rear because the pressure bled off after a bit. You should also have a proportioning valve at the rear supply line to allow more pressure to the front calipers for braking balance
Not saying that's all your issues, but it is a start. In most applications, the disc/drum M/C has built in residual valves for specific cars/trucks. The style that you have doesn't and will need to add them. That M/C should have both reservoirs the same size and should work

[RodnRudy]

Contact Pirate Jacks and tell them you are running disc/disc and they will be able to sell you the correct master and prop valve.
If your master cylinder is higher than your disc calipers you shouldn't have to run the two lb residual valves. The fluid shouldn't bleed back into the MC cause it's higher than the calipers.

[Shon]

got new MC and Combo valve from Pirate Jack. Same problem. The driver side spits out a stream of fluid but the pass side doesn't. Guess now I will replace that caliper and see if that is the issue.

[Nochance]

Think about how this system is plumbed. You have 1 steel brake line running from the front to the rear crossmember where it ties into a rubber hose that splits it for each side. So if you have pressure on one side you have to have pressure on the other side too, unless you have a restriction in the lines after the split or you just have air in the system. I would try and bleed the system again first and make sure you're only bleeding one wheel at a time or you will get the same result you are getting now. Pump up pedel open one bleeder and close, pump up pedal and open another bleeder, and repeat until pedal is firm.

[bbcmudtruck]

Just an idea here, but have you tried a vacuum pump bleeder? I got one from the parts store called "Mighty Vac" or something very close to that. Its an amazing tool and a must have in my garage. I've used that dang thing countless times. It contains all of the fluid and works great for a guy that doesn't always have an extra person on hand to help out. You can bleed the brakes all by yourself with this thing.

[Shon]

Well, I got my oldest son out there and pumped and pumped and got the new fluid flowing out the rear calipers and they work now. But will say the front is nasty and really should be replaced. So. Probably will end up redoing all the brake lines this year.

[Andy4639]

Originally Posted by Shon

Well, I got my oldest son out there and pumped and pumped and got the new fluid flowing out the rear calipers and they work now. But will say the front is nasty and really should be replaced. So. Probably will end up redoing all the brake lines this year.

Shon,
Ant adding rear disc brakes fun! I feel for you. I had my daughter helping me and it was a pain. I ended up jacking the truck up in the back as high as I could get it safely and finally bleed them.I'm still not really sure if they are set right though. I really thought the truck would stop on a dime after this mod but it's about the same as it was!