brakes

[LEONARD]

I put new shoes and wheel cylinders on rear due to a leaking cylinder,now can't get brakes on rear only. Could it be possible it's the proportening valve,
I have replaced single master cylinder with double cylinder assy from 1969 plymouth?

[Mark Merritt]

I never done A single to dual conversion but sounds like A proportion problem. If it was single I would suggest the shoes need adjusted more,as they are not self adjusted but need to do it manual (just till it kisses the drum) if you crack open A rear bleeder does air/fluid squirt out when pressing the pedal? Mark

[LEONARD]

Yes get fluid and air, when applying pedal front have brakes rear have none you can turn the drum shoes do not apply.

[Vanish]

Instead of asking several questions here is a diagram i found for you i hope this helps

[Vanish]

Another thing that could be your problem may be that the push rod That connects to your brake peddle to your master cylinder is to short and you are not making a full stroke check your line pressure at each line at the master cylinder.

[LEONARD]

Car still has 4 wheel drum brakes could I take the proportion valve out and still work like single master cylinder?

[big m]

Master cylinder could be defective, only creating pressure at the one port. Very common problem.

---John

[LEONARD]

thanks John, will try new master,do you know if the proportion will work in that system? I have that system on my 1967 dodge trk. that was a single master cyl and it has been working for several years.

[big m]

Proportioning valves are generally used in disc front, drum rear systems to avoid having the front brakes lock up before the rears. Probably not necessary in your case.

---John

[LEONARD]

Thanks John

[Vanish]

So what happened get her fixed ?

[LEONARD]

Better but not perfect I gutted the proportion valve that helped, think will put back single system.