Master cylinder?

[MoparFan]

Hi,
here is a picture of the Master cylinder on my 72 Dart (originaly disk brake , 4 pistons calipers)...seems a bite harder to find parts, like cover gasket for this model.

I often see master cylinder, with a big and a small reservoir, and with a more rectangular shape. What years are they from? Should I change to that model?

Thanks

 

[BigNat]

The Master cylinder with the asymmetrical reservoirs is for a disc/drum set-up only. If your car has 4 discs, the reservoirs should be the same size.

 

[JLP]

A 73 up master cylinder will work, it is odd that master cylnder is on there, it looks like the drum/drum type.

 

[MoparFan]

A 73 up master cylinder will work, it is odd that master cylnder is on there, it looks like the drum/drum type.

Yep strange setup, unless the previous owner has put the disc brake after having bought the car. It was equiped with the fixed caliper, when I got the car.

So this winter I will put a 74 (donor year) master cylinder for disc/drum (my setup) on the car. Do I need to change something else at the same time...I remember something about a rod, not sure what?

 

[64dartwagon]

you have to measure the spacing of the rod versus piston of master depth, and make adjustments or your brakes will be delayed somewhat, as the rod will have to move further if the piston is set further in, or sometimes if the rod is out to far for the new master it will cause your brakes to drag.

 

[65s]

Youro master cylinder might have been changed, anything can happen in 30-40 years of a cars life.

I'm trying to order up a dual disc/drum master cylinder from my local Napa guy and he keeps getting the wrong thing, even though the Napa computer shows the master cylinder I want, he gets the wrong thing in the box. The last one he got for me (just today) was the exact master cylinder you're showing up above! (but a nicely rebuilt one). Napa is all messed up man...

Any master with two reservoirs the same size was designed for 4-drum cars, but you can rebuild them to work with discs up front by removing the residual pressure valve inside. Some early disc cars seem to have an all drum master cylinder built this way. Personally I don't like them because you need the larger reservoir, as found in the later style master cylinders, for the front discs...they can take more fluid. I wouldn't trust one with two small reservoirs like yours.

Tom Condran's book "Performance Handling for Classic Mopars" talks all about master cylinders and bore size, etc. I suggest you read it. There's some important stuff about bore size and how to secure the pushrod and stuff.....Actually, here are some scans of the relevant pages I once posted for someone else.

http://www.enbcom.com/cuda/tech/tom_condran