I'm still fighting with my current brakes and I'm about to get a new master cylinder. My question is, are the master cylinders different from my '72 with all drums, to another Maverick with discs? And if they are, can I just remove the residual valve for it to function?
Yes the master cylinders are different. The disc brake master cylinder has a bigger reservoir for the front disc brakes.
I believe Frank is correct on the line fittings being different. I did the same conversion on my 72 and replaced at least one of the lines from the master cylinder to the proportioning/distribution block. Not a big deal. The master cylinder, rotors, calipers, and front brake lines I am using are from a factory power disc brake car, but the rest is the same 72 drum equipment.
Well I went ahead and ordered my discs and a new master. What was different about the lines? The placement? So I'll have to make a new line
Placement and line size is the same, but sometimes the flare nut size is different. If you are good at double wall flares it is easy to cut off the old flare, put the right nut on and re-flare it. Another option is a size adaptor but that is not a very clean look.
One note on that disc / disc master. And I checked with Scott Drake CS on this. It does not have a groove in it to lock the brake pushrod. Seems they figured most would used it with a power booster. So if it is a manual set up you will need a pedal stop to keep the brake pedal from coming out too far. Easy to do. The older Fords were like this. I also needed the adjustable brake rod to get the brake pedal height where I liked it.
The back kit? Do you mean the disc brakes? I have a 9" and used the JEGS kit. For that pedal stop - I just ran a hardened bolt in the right spot on the pedal mount and put a piece of rubber fuel line over it as a cushion. Works great! Here is a pic.
I am wondering how the adj. rod works out for you? I tried an adj. rod on my stock MC disc setup and had some issues. When I got the height I liked, didn't have enough travel to effectively stop the car like B4 I installed the rod. IIRC the brake lights were on constantly. Do you have the car on the road? I put the stock rod back in -- rather have the pedal a little high and have good stopping power. I do have a spacer ( "about 3/16") between the firewall and MC; was there when I got the car. I have been thinking about makin a spacer a little thicker when/if I take the MC off again.
I had to add an extension to get the rod long enough for my setup. As I too have an extra plate on the firewall to beef up that area because of the MDL hydraulic clutch. Did not want any flex of the stock firewall with that clutch. The rod extension was another adjusting nut and a stud added to the Drake one. You can see the 2 nuts butting up together in that picture I posted. I have road tested it and really like it. My set up is not power assist, so I get braking as soon as the pedal starts to move. As for the brake light staying on. That is really common with any of the aftermarket rods. Seems they make the flat side (the side facing the driver that pushes on the switch) extra big. If you hold up the aftermarket and OEM side by side you can see the extra material on that flat side. All you need to do is evenly shave a little off at a time with a fine grinder stone or belt sander. It doesn't take much trimmed off to keep it from constantly activating that switch. Really easy once you think about how that switch gets activated.
I never really noticed the difference in the rear of the OE rod against AM rod, never matched them. But, since U mentioned it, must have been reason lights on constantly. I think I will fab thicker new firewall spacer and work w/ the light sw thing as needed. May need some longer studs for MC. I think that will get the pedal where I want and have travel I need to get full activation/travel of rod. What ur opinion on that route? Thanks for info on the rod...