Hi I need help with my rear brakes. I have a 1991 camaro rs it was drum brakes but I swapped it for a 9bolt Borg warner with iron calipers. I blead the whole brake system getting straight fluid on all fours I put brand new calipers and a new master cylinder and a disc/disc proportion valve. I replaced the rubber hoses in the rear I have no leaks or air in my system. I don't think my rears are getting enough pressure. The only thing I didn't change is my brake booster rear calipers and my e brake cables there still the stock ones for the drum rear I'm not sure if that matters though?? Please somebody help me I have been trying g to figure this out for weeks!

 

If you have the old delco moraine calipers, the pad to rotor adjustment is managed by the emergency brake. If the cable is not correct it may not be adjusting the pad close enough to the rotor to apply enough pressure.

Those calipers were also defective in the actuation unit that the e brake adjusts. If I remember there was a recall and there is a repair kit.

I am swapping mine to a 9 bolt with PBR aluminum because of this issue.

Do a search on J-65 disc brakes and also on rear disc upgrades. You will find more information than you want on how this issue effects the workings of the braking system.

Good luck

 

OK so I'm gonna change my cables hopefully that helps! Also I went to go for a test drive but I couldn't stop at all ! Could it be my brake booster? My brake pedal only goes down half way then it feels like it hits a wall and the pedal doesn't move when I'm bleeding the brakes

 

If your pedal doesn't move at all....BOOSTER

 

IMO the biggest problem with the DM 10.5" rear brakes is the knee point on the prop valve is set way to low. The calipers don't get the pressure they need for balanced brake bias. I would recommend testing this with a brake caliper pressure gauge. If you find the pressure is low, its either the prop valve, booster, or master. If the front calipers test well (>1000psi) its not the booster.

If you find its the prop valve, I would recommend using an aftermarket adjustable prop valve. The OEM rear discs work well when given the necessary fluid pressure.

 

Hey I still can't get my brakes to work I've changed everything new booster master cylinder front calipers rear calipers brake pads and rotors all the rubber lines even the hard lines I ran 3/16 line from the front to the rear along with e brake cables. I just put a Wildwood adjustable proportioning valve on.. my motor doesn't make enough vacuum but I have an electric vacuum pump and its not helping. When the brake booster is full of vacuum the pedal goes almost to the floor. Its like there isn't any pressure.. I got straight fluid when I bleed the whole system. My front brakes won't even lock up. I bought I different master cylinder the other day and put it on and bleed everything it made the pedal rock hard and my front calipers were locked up. So I put the other one back on.. I just want to be able go stop wth

 

Until you address the adjusting mechanism in the rear calipers you are chasing symptoms, not root cause.

 

How do I adjust them I put the right cables on. When I bleed the brakes I can see the rear rotors moving so they should be working

 

Uits the actual adjustment mechanism within the caliper where the cable attaches. There was a recall. Do a search for J-65 problems and you should find info.

Without that mechanism adjusting correctly you have a pedal lower to the floor and limited pedal travel. Even if you see the pads move, they aren't moving enough to fully apply and since pedal travel is reduced you aren't getting a full application to the front brakes either which is probably what your issue is.

Doing a search you should be able to find the repair kit. I think Ed has them on his web page available for purchase. I am on my phone so don't have links to help, but it is something link flynnbye.com

 

Do new calipers come with the recall kit already installed? What would I have yo do to switch to pbr calipers??

 

That's a good question. I bet a quality brand reman would. Probably new as well.

There is some work to go PBR. Ed Miller makes a conversion kit to make it a bit easier, but I think PBR brake line threads are metric and your current lines are SAE threads.