Disc to Drum Brake Hell

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Just because of the way my brain works, I like to start at the beginning and assume nothing.
You are light on details that matter and others are just guessing based on life experience.
You bought a complete new Dodge/Plymouth mfg/marked disc/drum brake "kit"?
 
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All parts are matching for the year/make/model you are trying to convert to ? What sized rotors/drums ?
Bolt pattern 4" or 4 1/2"
Kit put together by someone or a Factory kit ?
 
HemiSSDart said:
Do you have the residual valve in the master? Do you have the proper proportioning valve for disc/drum brakes? I did a google search using "1970 Duster disc brakes and rear drum brake residual valve" and it talks about a 2 psi and 10 psi valve and what master and proportioning valve you need...
Click to expand...

OP's car is a '73. Last year for residual pressure valves was '72.
 
Big difference using a "B" body "kit" as opposed to using an "A" body kit.
So started with a 1971 base, slant six, 9" manual drum/drum setup and going for a ?? sized Disc and drum conversion ?
Never stated where this "new disc/drum conversion kit came from.
Every disc brake " conversion night mare" I have very seen has been a Frankenstein parts combination.
So starting from the beginning and don't just say it was new. Very few things are new and most of them don't work anyway.
Who assembled the "kit" ? Is it based strictly on Mopar parts only? No Gm calipers or aftermarket spindle adapters ?
What is the exact year that the kit s based on ? It matters a lot.
A-body disc brakes in 1970 have many different parts from say a 1973.
small spindles ? Or replaced with larger later spindles ?
The list goes on. What exactly are we working with. Do you have a name or part number of this kit ?
These are question that would never come up on a B-body car but definitely would on an A body
If the kit is good quality and is the proper application and was installed properly. It would work.
Just parts, but if any of those questions are Maybe or don't know, well....
Unless these parts were bought long ago or you have already started to modify things to try to fix it, my first call is always to the vendor who sold it.
Can't say much about problems if you did't even try to get the seller involved.
You paid money, they sold a " functional"product with some type of performance warranty.
Meaning that when installed per the sellers instructions, it will work.
If it doesn't the first call is to them, not online for possible fixes.
Sorry but that is the way it is. Never assume anything is functional and correct unless you test it your self.
Always read the instructions fully at least a few times and get your self familiar with the parts that were supplied and check against the list of promised parts. Always have a buddy familiar with what you are working on to help you.
If it is a "factory type" parts kit, you should be able to use the Mopar Factory Service Manual to give you all the proper steps and diagrams for installing the parts..
There should be no mystery here.

Details matter
 
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4.5" BBP. Bought as kit less MC and PV. PV came from in line it is the correct one for the A body...MH250. Was 9" drum/drum. Now has 10.5 on rear with 15" front is 14". 11" rotors
 

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Why then is the rear port spring loaded if there's not supposed to be a valve there?
 
Nuke463 said:
If so how do I remove it?
Click to expand...
Check for a valve by inserting a straightened paper clip into the hole in the flare fitting. If you can feel a spring loaded pressure, the valve is behind the flare. Tell us exactly how you have the lines installed. I wouldn't remove anything yet.
 
What Summit kit number ? If it was not factory, somebody cobbled it or it would be over the counter parts.
What was there kit number. What did you order the kit to fit exactly ? Why no direct answers ?
Trying to "guess" what you bought.
So rereading the first post " everything is new in the rear as well" What does that mean ? Factory original new parts ? Rebuilt? Calipers, rebuilt master cylinder, rebuilt wheel cylinders ? Or "new" US made preferably by a major brake manufacturer.
You never gave any details only what you tried ?
Rebleeding doesn't do anything unless there is air in the system and you would know it because the calipers would not stick, the pedal would keep going down because air compresses and fluid does not.
Here are some links to Factory Service Manuals. I don't know what year your "kit" is for so download the proper year and go to the brake section.
This is Factory information. Never, ever use a rebuilt M/C.
Almost every time we had a brake failure in the shop after a M/C change. It was a rebuilt unit.
We no longer installed anything other than a quality, new Master cylinder.
It is literally the heart of the brake system. When it fails, you car literally has a Heart attack(brake failure).
Sticking brakes that are not caused my improper installation will be a hydraulic blockage. eg Valve, debris, etc.
Always use a new, unopened bottle of premium brake fluid. Flush entire system. Did th the third brake line and block get replaced as well ? No Import parts from the East ?
From the west is ok Germany, Europe atc...


Click Here----------------------->Service Manuals – MyMopar
 
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slantsixdan said:
OP's car is a '73. Last year for residual pressure valves was '72.
Click to expand...
No where does he say it is a 73, the first post by the OP says 71 Duster, I read the entire thread and never saw 73 anywhere. Sounds like he has a cobbled together Summit aftermarket setup, you get what you pay for...
 
All of this being said, My '72 Slanty Duster came with manual 9" Drums all around, and has a large rear reservoir...it would have residual check valves in both ports.....I know,......wtf....
 
It sounds to me like the rod could be too long. A quick way to verify is to loosen the two nuts that hold the MC to the booster, and see if the lock-up condition doesn't happen.
 
RustyRatRod said:
I got my money on the residual valve still in the MC.
Click to expand...
I agree, to check for that you will have to remove the brass fitting in the rear brake reservoir line to the front brakes, I use a # 8 flathead sheet metal screw threaded into that fitting a 1/4 turn to maybe 1/2 turn max and then use a set of pliers (or whatever tool you want to use) to pull the screw and fitting out to see if one of those tiny flapper residual valves are installed or stuck behind that fitting or not, if so remove it and make sure you really retighten that brake line really tight so it reflares and reseal that fitting into the threads inside the M.C. to make sure it seals it up real well :thumbsup:
ITHS
 
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"Here's the problem. When I press pedal from brakes lock up and will not release after about 30 seconds later."

What are "FROM" brakes?:)

Sounds like the back of the caliper may be resting on the spindle. Its a known issue that some, if not most, calipers will rub against the upper spindle mount & a lil creative grinding is required on the caliper & spindle side to make clearance so the caliper is actually FREE FLOATING. Needs about 1/8" clearance. Use a credit card to check the gap.

Dick caliper.png


Dick caliper 2.png
 
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