Touchy brakes?

[punisher72]

I checked the length of the booster rod and it matches the depth of the master cylinder??? Thats as far as ive got!

[mattsclassic]

do you know if it is a facotry disc brake set up or an aftermarket disc brake conversion? We sell the aftermarket kits and this comes up with the guys who are running the GM prop valves. They sense a lost of pressure to the rear braking system so in turn only the front brakes working. It is an easy fix if it is a GM valve. They are a blass looking valve with 5 ports. WE have a Tech/troubleshooting/how to and instruction guide on our website that you might find helpful.
Kim
MCB
925-828-5555
www.mattsclassicbowties.com

[Bullitt-]

do you know if it is a facotry disc brake set up or an aftermarket disc brake conversion? We sell the aftermarket kits and this comes up with the guys who are running the GM prop valves. They sense a lost of pressure to the rear braking system so in turn only the front brakes working. It is an easy fix if it is a GM valve. They are a blass looking valve with 5 ports. WE have a Tech/troubleshooting/how to and instruction guide on our website that you might find helpful.
Kim
MCB
925-828-5555
www.mattsclassicbowties.com

That's some good info...thanks
http://www.mattsclassicbowties.com/contents/en-us/d296.html

[punisher72]

Thankyou mattsclassic! That looks like a good read. I will check my valve later on and see what i have. 

[PlumCrazyRTSE]

You don't by chance have a drum brake master cylinder on a disc brake car do you? 

That's the issue I've got on one of my Challys and I also have very touchy brakes.  I've got a correct master cylinder but haven't got around to replacing it yet.

[punisher72]

Heres some pics. Number on pro valve is KH 89410.

[Bullitt-]

You don't by chance have a drum brake master cylinder on a disc brake car do you? 

That's the issue I've got on one of my Challys and I also have very touchy brakes.  I've got a correct master cylinder but haven't got around to replacing it yet.

            I think we have a winner.... That looks like a drum/drum master cylinder. 

[72cudamaan]

Definitely sounds like the pushrod to the master is either wrong or not adjusted properly.  And no you cannot have too much vacuum. ( physically impossible without  a mechanical vacuum booster or something working as such.)

[punisher72]

I spoke to a valiant guy today. He said to undo the front brake line from master cylinder and pull out what's behind it then replace it all minus the spring! He says it will act like a disc/drum master cylinder. Has anybody ever done this? I'm going to give it a go. Cudamaan I checked the length of the rod to the master cylinder and they match up!

[Aussie Challenger]

Yes I have done it on many master cylinders but not on a MOPAR. Some earlier master cylinders had a smaller piston fluid displacement for drum brakes and you will end up with low brake pedal. When that check valve is left in the front disc's tend to drag because of the residual pressure in the lines.

[punisher72]

Thanx Dave. Where do u live in  ?

[Aussie Challenger]

I live in the Yarra Valley about 2 hrs drive due east from Melbourne, Victoria which is down south.

[punisher72]

Cool,Im sth brisvegas 

[Aussie Challenger]

Hemiken is up your way and nqkjw is up in Townsville, there are a few      on this board as a few E bodies have made the long swim south to spread their appeal here in Australia.
Lots of good info and our American cousins are all friendly, so are the other members from around the globe.   

[Supercuda]

Removing the residual pressure check valve from the line supplying the front brakes will correct the braking issue,and it will work more normally. I would line up a disc m/c as soon as possible, as it will also have the fluid capacity for the disc pistons.