Here's what I have. 31 Model A PU. I have 56 F100 brakes on the front and a Maverick rear end with stock drum brakes. I have installed new brake shoes and drums, bled the brakes,no leaks,everything good inside the drums with no leaky wheel cylinders. The problem is, I have a hard pedal but the brakes won't pull up. I have all the shoes adjusted correctly. The master cylinder is new also ( I did bench bleed it) its a 67 mustang item for drum brakes. Could it be the MC is bad,even a new one? I ran the car up on 4 jackstands and went slowly in drive,stood on the brakes and the back wheels were still turning even though I'm holding pressure on the pedal. Any ideas?
i have the sane setup on 3 cars and all work fine , so yours should too. my guess is maybe the shoes are not arced to the drums. pull the drums and see how much contact you are making
Seems like a '67 would have a dual master cylinder. http://oldcarbrochures.org/NA/Ford_...67-Ford-Mustang-Brochure/1967-Ford-Mustang-16
Are you certain you got the correct '67 Mustang all-drum M/C and not the disc/drum M/C? They did come both ways, you know. Andy
how did you adjust them? i adjust drum brakes by tightening them till they are "locked", [can't turn the wheel by hand], then back off six clicks. if it still is hard to turn back of a few more. when done all the wheels should be backed off the same amount. of course you will have to repeat the procedure once the shoes break in.
I got the drums MC, so the parts guy told me Do you have a part # for me to check? or how do I tell the difference?
Ok well I was going to tell you to adjust it full open if you did. If you have a stiff pedal, but no brake actuation I'd be looking for either an obstruction in the line that's blocking the fluid flow against the pressure on the master's piston or A mechanical hitch some place at the pedal or internal master.
I can have all wheels off the ground on jack stands,put the car in drive and push the brakes pedal as hard as I can and the back wheels still dont lock up, they stop but not locking up. I can give it some gas in drive and the back wheels turn slowly. Cant figure it out.
I'm with Dan on this,your master cylinder push rod may be to short and not applying enough pressure. HRP
Yep, the pushrod I got with the MC is actually a bit long to fit so I refitted the old one and the pedal does seem a bit low,looks like I may have to get an adjustable one. Did a search and an adjustable one costs a bunch like $65 !!
Adjustable arm. Many folks modify the stock one, thread both ends for a sleeve and find the right length, then either weld or pin the sleeve, or make an arm the right length. Buying the adjustable takes the labor out of it. Either way, I think you need an adjustable to find the right length/setting. Then make a permanent solution
One thought that comes to mind is regarding the bore diameter of the master itself. If the new master you got is of a different bore diameter, it could be why you aren't getting enough multiplication applied to lock the brakes I had a master cylinder I changed on a gmc box van with a hydro boost setup that turned out was put in the wrong box from the manufacturer. The van had minimal brakes once installed. I ended up taking it back off and then found out that it wasn't the right one for the application. Another suggestion that I use for adjusting drum brakes is to pick up an infrared non contact thermometer to check the temperature of the drums while test driving. If you get the temp between each side within about 10 degrees, you will have braking you will be happy with. Just some thoughts. Sent from my SM-T530NU using Tapatalk
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