My tentative plans are to end up eventually with rear disc brakes. My fronts are discs. I'm getting ready to adapt the hydroboost unit fom an '02 Mustang to the '57. I picked up the risidual valve with the hydoboost that was on the Mustang. I believe the '02 Mustangs were disc/disc. I was planning on doing the rear end last in the build, but I probably would like to road test the car before (and when) I get to that point with the '57 oem rear...and of course drum brakes.
So, my obvious question, can I install the disc/disc proportioning valve and still temporarily use the drum brakes in the rear?
the servo action of the drum brakes may make them lock up sooner,you will also need a 10 psi risidual check valve
Sounds like I need to figure out what I'm going to end up with(for rear brakes) and just go for it. Thanks for the input.
Rich I'm of the opinion you should plumb it up with a disc/drum master and the appropriate valve. Mixing is/may give you way more tail chasing then you can imagine. Use a master from the Granada and it's valve. When you make the change to the rear end change the master and valve at that time. Fittings should be real close to the same size if not the same.
Have to wonder why four wheel disc? The disc/drum is a very good system, best I can figure you're not going road racing and as I recall your area is not really mountainous so for a street car they (disc/drum) will perform exceptionally well.......just a thought.
Just to add, don't know if the bolt spacing is the same between the 02 and a Granada master....but there has to be a master out there that is close or the same....
My reason for the disc setup is I want the largest tires I can get on the back, and since way back when I started this project, I didn't make provisions such as tubbing, the disc setup should make for more room, at least make tire changes easier. I'm figuring narrowing 3/4 or so on either side as well. If it wer not for tire size problem, I would stick with the drums.
So, you're saying I shouldn't use the Mustang master until I get the discs in the back? I thought it was just a problem with the proportioning and check valves. I'm pretty sure the granada /normal style master won't work with the hydroboost as the Mustang master has the two mounting bolts top and bottom rather than at the sides.
Rich;
Why not just get an adjustable valve? I used a Wilwood one on the last conversion I did and it worked great. Just plumb in rear line and adjust so the front wheels start to slid (on gravel) slightly before the rears. Never had to touch it again. Then if you do change the rear brakes you can simply adjust to the new system. I have one here I purchased for the 57 that you can look at if you get up here for the Colorado show. Al
That's what I had in mind when I brought the subject up..to be honest that's what I thought a proportioning valve was for.
I'm still planning on the Colorado trip next weekend. I would like to take a look at what you've got. Hoping to hear from some of the other guys.
I took a second look at what I got with my hydroboost, and what I thought was an adjustable proportioning valve, is not adjustable. Al showed me the wildwood unit he had, and I found out wilwood also makes another unit that will give me more options with the mounting and plumbing. It also has a pressure switch if I elect to go that route instead of the pedal mounted GM switch I installed. The guys at Parr automotive confirmed that the unit can be used with both rear drum or disc brakes. I understand I'll still need a residual valve for the drums.