Whats wrong with my brake setup

[craigwhite89gt]

Ok now if you ask me this should work perfect. 73 MM calipers, 93 cobra MC and 3-2 conv. Stainless lines. After weeks of trying to make this work i took the car to a guy that builds cars/repairs them in his spare time. Big chevy guy but knows his ****. Well it still takes about 4 pumps for the pedal to get hard. Whats the deal here bad master cyl?? He is at a loss of what to do and so am i....

 

[Pod]

No idea what's wrong, but that's exactly the same set of parts I'm about to put on my car...

 

[Mustang5L5]

You are right. It should work. But if you are pumping the brakes to stop that means you either have air in the system or a faulty MC.

Are you sure you put the calipers on the right sides? It's easy to mix them up and being on the wrong side would make it tough to completely bleed all the way

 

[craigwhite89gt]

They bleed great about 500 times and the pedal takes about 4 pumps to get hard and hold pressure. As soon as you let it go about 5 secs later you have to pump it up again. Im going to get another master cyl. tommarow.

 

[duner]

They bleed great about 500 times and the pedal takes about 4 pumps to get hard and hold pressure. As soon as you let it go about 5 secs later you have to pump it up again. Im going to get another master cyl. tommarow.

Did you bench bleed the master cylinder?

I had a similar problem. Didn’t take four pumps but the pedal was always mushy. This was solved by bench bleeding the MC.

I’d bench bleed the MC before dropping dough on a new one.

 

[Pod]

I’d bench bleed the MC before dropping dough on a new one.

For future reference, how do you bench bleed a MC?

 

[duner]

For future reference, how do you bench bleed a MC?

Here's a link to a pretty good write up. I know it's a Chevy site but the pics are decent.
http://www.superchevy.com/technical/chassis/brakes/0509sc_bench/

I just did mine a few weeks ago. I disconnected hard lines at the block leaving them connected to the master cylinder. This saved me from having to buy additional fittings. You do not need to remove the MC from the car. I left the MC installed and used the brake pedal to actuate the piston. Pretty easy to do.

Keith

 

[Pod]

Thanks very much for that link.

 

[craigwhite89gt]

sorry for late reply... Yes MC was bench bleed.

 

[2000xp8]

Are these calipers chain store rebuilds?
If so, they are garbage. When it comes to brakes i trust only ford dealers. And i don't want to hear any of that "same manufacturer" crap, never holds true.
I'd rather have a used factory ford part, then a rebuilt chain store part.