Alright heres the deal...

Just bought a 79 SA a few weeks ago, and from the day we bought it we have had troubles with the brakes. The previous owner told us that the drivers rear brake drum was smoking. we havent touched that brake, because we have yet to see the smoke. However, the front calipers were stuck, so we replaced both of them, and the rubber brake hoses. after that, we went to bleed the brakes, the master cylinder and the rear bled fine, but on the front we couldnt even get one drop of brake fluid to come out. So we disconnected the brake lines, and checked to see if the brake fluid would come out of the ports where the steel brake lines connected. Nope, nothing was coming out when we pressed the brakes. so we replaced the master cylinder.

Now we have a new master cylinder, and still the front brakes wont bleed. we know there is no clog in either the stainless or rubber tubing, because we hooked up an air compressor and blew through the hoses both ways. So now I am at a loss, I have no idea whaty could be wrong with it. Please help me, oh gods of RX7club.com!!!

Ryan

 

Did you bench bleed the new brake master cylinder? Cause it sounds like you have airlock since installing it.

John

 

I bled the master cylinder, and fluid came out just fine. Could it be the proportioning valve?

 

Must be, It is the only part you have not checked. Some times the Valves in there will stick.

Did you figure out how to adjust the rears? They are a bit odd if you have never done them before.


Also the 79 is not known for having the best brakes. They changed the style of the front and rear on the 80+ cars. I plan to change my fronts to 85 and the rear is going to be an 84 with LSD and Disk.

 

The left front caliper gets fluid directly from the master cylinder, so the proportioning valve can't be it.

I was going to suggest a bad rubber line acting as a check valve, but you said you replaced those, so that can't be it.

Get a spare master cylinder cap, drill a hole in it, and install a tire valve. Fill the master, open one of the bleeders, and *SLOWLY* pump air into the master with a bicycle pump. Works like a charm.

 

Well I unhooked all the brake lines from the master cylinder, and had my brother hop in the car and push the brake, fluid came out of the port for the rears, but not to the ones for the front, so i put the rear line back on and did it again, and theres no fluid coming out of the front end. I think this is because fluid runs from the master cylinder, into the proportioning valve, and then back into the end of the master cylinder, because like i said, this master cylinder is a new rebuilt unit, so i know it is functioning properly.

We also adjusted the pushrod yesterday to no avail. This is confusing the crap out of me.

 

Ok, When you took the line off the MC for the front brakes you did not get fluid out. Right? either you have air lock or although its new could be (but doubtful) a bad master cylinder.

How to bench bleed correctly.


Did you do this, are you getting air?

John