i replaced the single chamber 53 ford m/c with 67 mustang manual drum/drum dual chamber. cannot get any pedal. am on second m/c this one i bench bled. front chamber is hooked to front brakes and rear to rear. car is drums all around. have spent an ungodly amount of time and have researched until i can't read any more. can any body come up with a solution before i rip it all out and go back to my single chamber? thanx for your help. larry PS car is my 32 chev coupe not '53 ford
are your brakes adjusted up good and snug, even adjust them up to lock the wheels while your bleeding will help, do you have free play in the pushrod, return spring on the pedal?
Are you getting any fluid from the beeders at each wheel. There's got to be air in the system somewhere. Do you have anyway to isolate the front system from the rear. Put a plug in the rear line of the master cylinder to eliminate that line from the circuit. Try just bleeding the fronts. Try the same for the rear. I was having the same issue with my race car and thought I had bled a gallon of fluid. Then a mechanic buddy of mine told me to pump the pedal slowly because I was pumping it to quick creating air bubbles. As soon as I slowed my pedal pumping down to slow and steady, sheet howdy, we got all of the air out and the pedal came up.
I'm thinking the rear cylinder with the larger reservoir goes to the front brakes on those. That way you apply the front brakes and when they start to take hold it energizes the rear brakes. Looking for a diagram of 67 Mustang brakes but while I can find a lot of pictures with arrows on Mustang forums I haven't found a drawn out diagram. Other than that: Push rod from pedal to piston adjusted correctly or the correct length? Shoes on all four wheels adjusted correctly? I don't think I need to ask you if you have the drums on it but it seems that a couple of guys have tried to bleed brakes with the drums off and laying on the bench lately.
maybe im wrong but the line on the M/C need to be switched. and when bleeding the lines i always went to the furtherest bleeder from the M/C starting at the rr>lr>rf>lf
I did some more hunting and found this page where a guy converted his 65 Mustang fruit jar brakes to use a 67 dual master cylinder. Good info for any drum brake guy putting a dual mc on a rig. http://www.thompdale.com/brakes/brakes.htm He also states that the front outlet goes to the rear brakes and the rear outlet goes to the front brakes.
Agree with all who said lines should be front brakes to rear of MC, back brakes to front of MC. I like to gravity bleed,,,,fill MC, leave cover loosely sitting on MC, open one bleeder at a time starting at the RR, then LR, RF, LF. keeping an eye on the MC and topping up as needed. Once I get a steady drip at each wheel, one at a time remember, then I bleed in the same sequence with a helper pushing the brake pedal, not pumping but applying pressure on pedal and hold, open bleeder, pedal goes to floor, close bleeder, let pedal up, repeat until there is no air. I have used this method for years with great success.
tell us whether the MC is on firewall or below floor.....you can gravity bleed if on firewall.......also you might try using a vacuum bleeder at the wheel cylinders...most parts stores have one
also, how are you bench bleeding the cyl? on or off the car? if you are doing it off the car that might be why too... the way I like to "bench" bleed em is on the car... pump up the pedal and crack one of the brake lines, just as you would a bleeder screw.... then do the other one, this has worked well for me in the past...
Good points,,,,,I assumed it was on the firewall,,,, if it is below the floor, gravity bleeding is probably out. Vacuum bleeders do work well.
thanx to all still at it. moved lines and think starting to gain. but had to nap for a bit not as easy at 69+ as it once was. sorry for any confusion m/c on firewall. yes drums on. it has been a project!
as i mentioned moved lines and then plugged rear. i believe this is what actually got "it" going, as i got a lot of air out of drivers front! then rehooked back and bled total system a few times and now have pedal. Thanx to all who contributed, a SPECIAL THANX TO MR 48 CHEV who ferreted out a terrific aticle. larry
I had the same problem when I replaced the M/C on my Ford Fairlane years ago. Finally took it to a garage and had it pressure bled. That solved the problem.
Also make sure the rod is going all the way in the master cyl, im thinking i did the same swap once and the rod wasnt long enough for the dual master..... just a thought =)
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