Thread: give me a brake!!!

Tweet

Did you bench bleed the new master cylinder before installation , if its new ?
Are the valves installed correctly ,meaning is the flow the right way?
You could try the vaccume pump type beeding ,if pedal pressure for bleeding is a issue.

Yes it has been bench bled and the values are right. also the bleder screws are at the top to bled all the air out. I pluged the front outlet on the master and the brakes worked alot better. as soon as I hook the front line back up no brakes.

Try to hook the front brakes to the back hole in the master and bleed them ,then re attach to front,if possible?
Bad calipers ?
Bad master cylinder ?
Could be tons of air trapped still,did any fluid at all come out the front?

Hooking the front to the working master cylinder fitting would rule out calipers..................seems awful unlikely that both calipers would be bad or they would not be able to be bled...........,my bet is on the master cyclinder not working correctly.
Swaping the connections would rule the front calipers and determine if the one port was bad on the master cyclinder.
Could be air in the master cylinder still too,might loosen the front fitting and see if fluid is being moved at the cylinder?
I know the motto is bleed ,bleed and bleed some more ,when it comes to brakes.

How tight are the rear shoes adjusted up, and how much clearance do you have in the front rotors to pads? I would crank the rear shoes maybe a little tighter than you intend on finally running them, and start bleeding at the furthest corner.

It sounds to me like you have something going on in the front, since it did improve when you blocked those off.

Don

Yes I have adj the rear shoes real tight and the front pads are new. Although the master checked out ok I may try another one.

So I have pluged the outlets in the master cyl and it has a firm pedal. I then left the plug in the front line and hooked up the rear brake line and had a firm pedal. As soon as I hooked up the front line I had no pedal. I then clamped off the rubber brake line at each front caliper. I had a firm pedal but when I unclamp no pedal. I have replaced the calipers 2 times and vac bled and foot pump bled and still no pedal. This is a 78 camaro sub frame with 78 brakes. Chevy changed calipers around 80 to what they call a slow drag cal. This cal will not work with a reg master cyl. Anybody know how to check on what cal this could be. I am running out options?

Same here... It has to be in the calipers. If you have a pedal with both rubber hoses clamped at the caliper then thats all thats left. But 4 bad calipers is hard to believe.