brakes not working right

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Onus Gumboot

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I have a '73ish dodge swinger I'm trying to get on the road. New brakes, shoes master cylinder, wheel cylinders. I can't get them to work properly. They work sometimes, then they barely work, and sometimes, they lock on. Bled the master cylinder before installing, bled the wheel cylinders repeatedly. Adjusted the brakes twice, and they seemed to improve for a while, before going back to part time. Any ideas?
 
Check to see if your compensating ports are returning fluid.
There can be several reasons for fluid not returning;
1) as mentioned, a too-long pushrod
2) a pedal not parking properly
3) failing brake-hose(s)
4) faulty seal retraction
5) stuck rear wheel cylinders
6) brake shoes not parking
7) a faulty Combination valve
8) dirt in the system, plugging orifices.
9) kinked lines.
10) interference from the park brake.
 
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Rubber hoses are new? If they are old they tend to either make the brakes stick on or not reliably pass fluid when they fail internally
 
First off, thanks for the help. It's great having somewhere to ask these questions. It's been 30 years since I last got serious about working on cars. Second, this gives me a couple of directions to go. All parts and hoses are new, with the exception of the hard lines going to the back brakes. They seem good, at least on the outside, but could easily have crud inside. I will change those too soon. I cleaned out the reservoir, which somehow did have some grit in there, and refilled the thing, and so far, the brakes are no longer sticking. They seem to work better. so I suspect at this time, there was some gunk in the lines, that somehow worked its way to the cylinder.
Thanks again, and I will post in the future if problems persist.
If it is a problem with crud in the master cylinder is there a good way, other than taking it completely apart, to clean it out?
 
If the M/C pushrod was removed/replaced, the M/C pushrod pivot bolt can be installed/tightened in a manner that causes it to bind, giving a funny " feel", restricting pedal return, and by not returning all the way will affect the M/C operation.
Try loosening the pivot bolt 1/2 turn to see if prob goes away.
If it does, fix the issue with the bolt.
Good luck
 
This could also be something like corrosion / rust/ gum in the lines/ tubing, and or in the distribution block which is also the piston warning light switch.

My first thought, already mentioned, is to jump on the master and investigate that. The pedal/ pushrod MUST allow the master piston(s) to retract past the ports in the bottom of the master. YOu can see this, maybe with another person, by applying the brakes, and if necessary, pumping them a bit to get pressure up, and then releasing. When they release, watch in the master reservoir and look for both ports to "erupt" a small amount visible up into the fluid. Sometimes these will actually geyser up and splash out of the master, so use rags, etc, to protect.

If you don't have decent pedal on "one pump", and yet it's "hard" when finally pumped up, suspect adjustment. I always turn the wheel and tighten the adjuster until the wheel will not turn. Then back off "some" like maybe a dozen "clicks" and same thing on opposite side. This should be some "even." Until they are worn in some, it is normal for some drag

Also if the drums are excessively worn and / or have been turned oversize, the shoes may not fit well enough. Back in the day, you used an "arcing" machine to match the curvature (radius) of the shoes to oversize drums. In the REALLY old days, you might even shim lining to make it "bigger" to match worn/ turned drums.

This condition causes the shoes to only contact the center area of the shoes. Not only do you not get full shoe contact, and therefore not full braking action, but this overload of the lining overheats it and causes glazing, further reducing effectiveness
 
Are the automatic adjusters on the correct side of the car?

Are there groves in the backing plates where the shoes ride?
 
I didn't know they made vehicles in 1973ish.
 
Onus Gumboot said:
I have a '73ish dodge swinger I'm trying to get on the road. New brakes, shoes master cylinder, wheel cylinders. I can't get them to work properly. They work sometimes, then they barely work, and sometimes, they lock on. Bled the master cylinder before installing, bled the wheel cylinders repeatedly. Adjusted the brakes twice, and they seemed to improve for a while, before going back to part time. Any ideas?
Click to expand...

By the way if you are unaware, (and you NEED to nail down the year/ model!!) You can download a 73 factory manual, free, from MyMopar. It is there from a few of us here. There is no 74 manual, if that is what you have, PM me if you want one

The wiring between 72, 73, and 74 (and 75/ 76) are all quite different
 
harrisonm said:
Same as an 83 Corvette. When you were at work, did you, or your guys, ever get a phone call for brakes on an 83 Corvette?
Click to expand...
I cannot say that I remember, but it wouldn't surprise me one single bit to see them in OReilly's system. lol
 
Onus Gumboot said:
I cleaned out the reservoir, which somehow did have some grit in there, and refilled the thing, and so far, the brakes are no longer sticking. They seem to work better. so I suspect at this time, there was some gunk in the lines, that somehow worked its way to the cylinder.
Click to expand...

Oh, it absolutely did. Rust is heavy, it falls down to the wheel cylinders. It sounds like you didn't bleed each wheel cylinder? Brake fluid should be freshened every two-three years.
 
RustyRatRod said:
I didn't know they made vehicles in 1973ish.
Click to expand...
I call it that after finding out the engine is 76 or newer, the rear end is probably '72, the drivers side door is not the same as the passenger side, so I have no idea what year it is. Which is a problem as it's missing the part that keeps the window from flopping around, which is clearly different than the one on the other side.
It's a frankenstein '73ish car
 
Demonic said:
Oh, it absolutely did. Rust is heavy, it falls down to the wheel cylinders. It sounds like you didn't bleed each wheel cylinder? Brake fluid should be freshened every two-three years.
Click to expand...
I bled them several times. Ran a whole quart bottle of fluid through it in an attempt to be sure it was clean.
 
Onus Gumboot said:
I call it that after finding out the engine is 76 or newer, the rear end is probably '72, the drivers side door is not the same as the passenger side, so I have no idea what year it is. Which is a problem as it's missing the part that keeps the window from flopping around, which is clearly different than the one on the other side.
It's a frankenstein '73ish car
Click to expand...
You need to find out what year it is man. Wiring harnesses were different dang near every year. Look at the VIN on the body on the dash.
 
67Dart273 said:
By the way if you are unaware, (and you NEED to nail down the year/ model!!) You can download a 73 factory manual, free, from MyMopar. It is there from a few of us here. There is no 74 manual, if that is what you have, PM me if you want one

The wiring between 72, 73, and 74 (and 75/ 76) are all quite different
Click to expand...
It's a '73 car. As I stated in response to another post, the engine is at least '76, different heads than earlier, the rear end is possibly '72, which may be part of the problem now that I think about it, and the drivers door is from a different car. The window stabilizing part bolts on differently and is missing, so I don't know what year it's from. But the majority, the body, is '73.
 
If the brakes don't work on the right, then plan your drive so you only turn to the left... :steering:

Maybe enter NASCAR....
 
Onus Gumboot said:
It's a '73 car. As I stated in response to another post, the engine is at least '76, different heads than earlier, the rear end is possibly '72, which may be part of the problem now that I think about it, and the drivers door is from a different car. The window stabilizing part bolts on differently and is missing, so I don't know what year it's from. But the majority, the body, is '73.
Click to expand...
Now we're gettin somewhere. I would do like Del said and go download that free service manual and read through it. It is an invaluable resource.
 
67Dart273 said:
By the way if you are unaware, (and you NEED to nail down the year/ model!!) You can download a 73 factory manual, free, from MyMopar. It is there from a few of us here. There is no 74 manual, if that is what you have, PM me if you want one

The wiring between 72, 73, and 74 (and 75/ 76) are all quite different
Click to expand...
I probably sound like an idiot, but I'm just old. What is PM?
 
Onus Gumboot said:
It's a '73 car. As I stated in response to another post, the engine is at least '76, different heads than earlier, the rear end is possibly '72, which may be part of the problem now that I think about it, and the drivers door is from a different car. The window stabilizing part bolts on differently and is missing, so I don't know what year it's from. But the majority, the body, is '73.
Click to expand...
You basically want to download the 73 manual at MyMopar. It then matches the body/ wiring. The other parts you mentioned are essentially the same
 
66fyssh said:
On FABO it's called a "conversation". You click on the member's screen name, then click on "start a conversation" and send them a "private message".
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Thanks. I don't even own a smart phone and have only once sent a text message. On my flip phone. That's how out of touch I am with this internet communication thing.
I never would have gotten "conversation" out of "DM"
 
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