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Discussion Starter #1
I recently upgraded my single bowl master cylinder to a duel bowl with the kit from CJ Pony. Ive never been thrilled with it since installation. It feels like ti takes a lot more effort to stop now. Today, I did a panic stop and found that the rear brakes lock up. It seems like the rear brakes are doing the majority of the braking. Should I install an adjustable proportioning valve to my rear brakes? If so, would that improve the overall braking of the car ? Oh, Im running the original 4 drum setup.
 

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It's easy enough to do. First I'd double check there's not a issue with the MC. Maybe try to swap the lines and see if it still locks up the rear. Yeah it's a nice feature to fine tune.
 

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Discussion Starter #3
One thing that concerns me about the master cylinder that comes in the kit is the fact that both bowls are the same size. The fluid is equally divided unlike most master cylinders where the bowl for the front brakes is larger than the rear.
I think my MS is functioning OK. Swapping lines is not as easy as you think. I'd have to buy some thread adapters for one thing and risk damaging the pre-bent lines from the junction block by trying to move then that much.
 

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For a drum/drum, both bowls should be the same size. It is the disc/drum setup that have bowls of different sizes. Having an adjustable prop valve will allow you to fine tune the amount of pressure going to the rear. I don't believe your original dist block was made to use a dual bowl m/c so having a prop valve should help, in relation to pressure control.
 

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Proportioning valve is not needed on drum/drum setups.
Does the master have residual valves in both ports?
Did you plumb it up--front bowl of master to rear brakes, rear bowl front brakes?
The factory distribution block--Did you use it, plug the port that was rear brake line, run rear brake line straight out front port of master to rear?
If rears are locking up, I'd revisit the condition of all components-Including wear on plates/drums.
 

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Discussion Starter #9
Its plumbed exactly as the instructions called for. Rear brakes to front res, front brakes to rear. I used the factory distribution block. Shoes and drums look great.
 

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How sure are you that the rear brakes are adjusted properly? I ask because the same thing happened to me in my '66 years ago when replaced the rear brake shoes. I had adjusted them too tight. I backed them off a bit, and no more problem.
 
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