Higher pedal position Hey todmeg, I swapped my master cylinder and had the same issue, I'm assuming you got a MC for a granada disc/drum right? Well the one important thing is that the MC pushrod for a granada is a different length than that of a mav (longer). So you have to put a mav pushrod in or get a MC from a 74 mav with manual disc. I haven't done the swap yet, I need to hit a junkyard and find a junk MC to pull the pushrod off of to put my pedal back where it belongs. Jonathan
Two things to look at. Is the master cylinder being operated far enough to make pressure, not going against a stop? The disc/drum system is supposed to have a different master cylinder that has a smaller internal diameter to help apply more pressure to the system. Is the master any good?
master is new. Calipers and wheel cylinders have been rebuilt. New lines. Rebuilt Bias valve. I've got to be missing something, probably something simple. The 4 wheel drums worked waaaay better than what I've got now!
dont know if it makes any difference or not, but the discs are 10" from a 77 maverick that had power brakes. I just found out that in fact they are not granada brakes
Re: petal No, they are different because you are comparing a manual and power disc assembly. The manual brake pedal assemblies, whether they are disc or drum, are the same.
Charlie is correct and Corbin was clearer in his answer about the brake pedal difference between power and non- power brakes. I was refering to the manual drum pedal compared to my power disc pedal set up. After reading my intial reply, I can see why there was confusion. Sorry Tony
Running out of places to go, except to say that on the proportion block, there are front and rear ports and cannot be reversed. I have the change over with Mav parts except the proportion block is from a later Mustang with all the line connections reterminated with the right nuts to fit each port etc. The job came out with higher line pressure on the rear causing lock up when tested doing a low speed panic stop on smooth asphalt so the rear tires could be heard. I had installed an adjustable valve in the rear line and reduced the pressure till all four wheels lock at the same time and maximum stopping power is obtained. Think it over and see if you made an error somewhere. Good luck. It will work when all is right.
Only thing left to take a look at is the proportion block. The block has specified ports for front and rear and can't be reversed or mixed. Mention was made of 10" front discs. Most all Mav with disc, have 11" discs. according to the books. Mustang II has smaller discs. I have the conversion with 11" discs, power brake master, late model proportion block and an adjustable valve in the rear line. Testing was done on a smooth asphault surface. Dialed in pressure reduction till the rear drums no longer locked up first and the best braking feel was obtained. Recheck your work to see if an error was made feeding the block aaembly. When it's all setup right it will work ok. Good luck.
Also installed a junction block from a later model car, I think either a fairmont or mustang, cant remember. I guess it's off to the junkyards to find some 11" rotors. Will I need the calipers and spindles too? BTW, I think the rear brakes arent working right either...I can jack up the rear, and with some effort on the pedal, the rear just slows down, doesnt stop. No air, no leaks, nothing. Got me bumfuzzled! I even checked the shoes to make sure they were on the right way, primary and secondary shoes in the right position. If I cant find anything at the salvages, I'm putting drums back on!
