Did I screw up my distribution block?

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Clelan

Clelan

Inferno Red Duster
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The patient - 74 Plymouth Duster, Factory 318 car with power disc/drum brakes. I bought the car disassembled but the brake system was together and intact so I don't know if it ever worked 100% when the car was taken off the road for restoration.

The problem - No fluid getting to the back brakes.

I attempted to bleed them and no fluid getting back there. The fronts bled fine. I tried to remove the hard line out of the distribution block to the back brakes and see what I had there. It would not come out so I soaked it in penetrant. My impatience led me to pull the plug out of the bottom of the distribution block. The plug, the spring seat and the spring came out in my hand along with some but not lots of fluid and some but not lots of black specs of crap. The spring seemed to be under a quite a bit of pressure when I removed the plug but all went back together fine. When I pulled the plug a second time, the spring pressure was not there. The spring sat up in position and wasn't forced out by spring pressure.

Did I screw up my distribution block, prop valve, brake trouble switch?

Is it possible my fluid blockage is in the distribution block or is it more likely to be in the lines to the back?

My FSM is at home so a picture of the inner workings of the distribution block would be great if someone had one.

Any ideas to ponder or experience with a similar issue would be great.

Cley
 
I bought a kit for mine from muscle car research. I downloaded and printed the detailed rebuild instructions, should be doing it this weekend. Have to reinstall it before installing new exhaust system.
 
Factory service manuals plainly state that proportion valves are not serviceable. At the same time, engines, transmissions, carburetors, are serviceable. Go figure
None of the above would prevent at least 1 aftermarket vendor from offering a kit.
Maybe the owner can do what factory trained service techs cannot. I wouldn't attempt it even if that kit included holy water.
 
89on35s said:
What was the problem that prompted you to rebuild yours?

Cley
Click to expand...
A couple things, I did the drum/disc conversion to my car and upon completion I had a small drip from the valve. Unsure whether it is one of the five lines that attach to the valve or the valve itself I opted to remove the valve and rebuild it. The valve was built in December of 1971 and my research led me to believe that the prudent move will be to refresh it. I have a vacuum kit for bleeding brakes and BF is cheap so it was an easy decision. FWIW, before I pulled it back apart I had great pedal and good braking. The real issue for me is that I cannot tolerate a BF drip and once the exhaust is in, it is too tight to properly access. sooooooo-----fix it now!
Good luck with yours-----DR----:)
 
Someone "on the web" had one torn apart. But "what do you have?" You should not have a dist. block you should have a combo prop valve and dist block, often just called a prop valve.

Here's one......

1970 - 1976 Mopar Combination Valve Autopsy | Muscle Car Research LLC

Might be better.........

1970 - 1976 Mopar Combination Valve Rebuild | Muscle Car Research LLC

I searched

mopar proportioning valve rebuild - Google Search

From the FSM

prop_warning.jpg
 
I didn't see if you checked for rear pressure right out of the master? (Front connection on the master goes to rear)
 
I didn't check there yet. I started in approximately the middle (output to rear brakes at dist block) but couldn't crack the fitting. I was hoping to prove output of fluid at that point. I did notice however that when I pump the brake pedal I see a bit of fluid jump in small reservoir.

Cley
 
Thanks for all the great information. The problem was in a crushed rear hose. I had pinched it off to save a mess when swapping the rear ends out. I never imagined it wouldn't bounce back. Fortunately I had a new rear hose in the cupboard so I am all bled and good to go now. I guess I'll find out if I screwed up my rear brake bias when I finally get to drive it. That's another "Note to Self"!

Cley
 
As to the valve being Non-serviceable, I imagine that is because the O-rings on the safety valve are not Os but rather specially shaped rectangular sections. The square section is better at preventing fluid migration from one side to the other,during a fluid failure, cuz when you feel one side go down, there will be panic, and a huge pressure spike will be the result when you 2-foot the pedal. That spike and all subsequent spikes (until you fix it) has to be contained. Regular O-rings won't cut it.
And Ima guessing Ma didn't retail those special rings,back in the day.Those combo valves are not rocket-science,and unless the rubber is swollen from contamination, they are easy to service. I have had many apart
 
89on35s said:
Thanks for all the great information. The problem was in a crushed rear hose. I had pinched it off to save a mess when swapping the rear ends out. I never imagined it wouldn't bounce back. Fortunately I had a new rear hose in the cupboard so I am all bled and good to go now. I guess I'll find out if I screwed up my rear brake bias when I finally get to drive it. That's another "Note to Self"!

Cley
Click to expand...
daaahh... :BangHead: and a little :lol: too...
 
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