brake blunder :-(

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Dart/Valiant

Dart/Valiant

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The front part of my car's master cylinder is draining very slowly, but enough that I suspect a leak. I was checking the wheel cylinders, in case I saw the leak, but stepped on the brake pedal without putting the drums back on first! Obviously, impossible to put them back, how to be able to replace them? The brakes are complex with a lot of very strong springs.
 
Dart/Valiant said:
The front part of my car's master cylinder is draining very slowly, but enough that I suspect a leak. I was checking the wheel cylinders, in case I saw the leak, but stepped on the brake pedal without putting the drums back on first! Obviously, impossible to put them back, how to be able to replace them? The brakes are complex with a lot of very strong springs.
Click to expand...

Did you try to open the bleeder on the back plate to relieve the pressure and set the pads in place and close bleeder.
 
shoes, I assume? the return springs will pull them back. they may have expanded past their guide pads, and have dropped into the recess near the edge of the backing plate. Just pry or pull them out of that recess and they'll pull back. You may have to contend with other linkage which may have come loose by over extension. If worse comes to worst, just pull it all apart and reinstall the brake shoes.
 
Breaks are one of the things that look so complex but are so simple.

Download your cars Factory service manual from mymopar.com, the repair procedure is in there.

As others have said, probably only need the pull the shoes outward (toward you when you are sitting facing the axle flange) maybe 1/2 to 3/4"

The pistons in the cylinder could have also been pushed out of the cylinders, that will take a bit more finesse to reset.

You can do this.
 
The other issue is "did brake fluid leak" on the shoes? If you are patient you should be able to retract them, but WIRE the opposite shoes in place as when you attempt to retract one side, the opposite side may be forced further out and pop the pistons past the seals

"What you might try:"

"Rig" some "haywire" to each shoe near the top and experiment with the length and loops in the ends or just wind the remaining ends around............some vise grip welding clamps or channel locks. Squeeze the pliers and the tops of the shoes should return. You'll have to wiggle them to get them to seat into place
 
AND NOW AN ANNOYING story from the old days.

Naval Station Treasure Island, 68-69, going to Navy ET-A (electronics) school. I "fell in" with a new friend who later would be the original owner of.......and sell me.......my 70 RR 440-6 car. At the time he had a 65 Chevelle with a 350/ 4 speed and Ralley wheels swapped from a nearly new wrecked 67 Camaroo

Anyway he HAMMERED that thing, much to my delight. One day, He and I and a friend of mine exited TI towards San Francisco. He would the @#$%^%@ out of the thing in 1st (220 low, 3.08 rear) and slammed it into second. WHAM!!! BLAM!!! NO THANK!!! YOU!!! MAN!~!!

So we slid (rear locked) into one of the bridge emergency cutouts and jacked it up onto the spare tire, and pulled the rear cover (10 bolt) and fished out the pieces. Some funny "clips" fell out. Neither I nor my buddy knew what THEY were. Put it together, here comes the tow. He has a NICE big rubber bumper. We tell him "We think it will roll" and he is going to push us off the bridge.

So he gets us up to a "safe" speed and we take the first long, sloping ramp off the bridge, and NOW BOTH REAR TIRES are rubbing the fenders because the C CLIP AXLES have come out!!!! Bear in mind this is a 65 BEFORE THERE WERE tandem brake systems!!!!!

George taps the brakes, and thought really really REALLY fast (he is no dummy) and HIT THE LINELOCK and stabbed the brake just enough to get pressure into the front and to hold it. So the car finally slowed and stopped at the bottom of the ramp.

George, the "guilty party" at the Treasure Island amateur radio club. No idea when this was taken, as he went to "A" school at some point and later, when I met him he was an E-5 going to "B" school

Burton.JPG


George after he learnt hiz'n lesson. This was taken in 70 when the car was new. We had been to Lions where he trophied in PS That is the one car I wish to hell I still had, although the original 440 "left us"

I was stationed at NAS Miramar, San Diego, he was on a ship in port at Long Beach

_mg_6204cs-jpg.jpg
 
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I managed to put the drums back on, but one thing leaves me confused. I can't find a leak anywhere, not a big leak, but the front part of the master cylinder is slowly draining. Every 150 or 200 miles, especially in city driving, I have to adjust the level. Internal leak? (no power brake to suck the fluid) At some point, the liquid should be able to escape somewhere!?

Dart/Valiant said:
The front part of my car's master cylinder is draining very slowly, but enough that I suspect a leak. I was checking the wheel cylinders, in case I saw the leak, but stepped on the brake pedal without putting the drums back on first! Obviously, impossible to put them back, how to be able to replace them? The brakes are complex with a lot of very strong springs.
Click to expand...
 
Fluid HAS to be going somewhere. Look carefully at all 4 tires on the inside. Fluid normally will form a "sheen" --when rolling--or streaks when stopped on the tires. You should be able to see around the cylinders with drums removed.

Every 200m is a LOT of fluid. Do any of the brakes "grab?"
 
67Dart273 said:
Fluid HAS to be going somewhere. Look carefully at all 4 tires on the inside. Fluid normally will form a "sheen" --when rolling--or streaks when stopped on the tires. You should be able to see around the cylinders with drums removed.

Every 200m is a LOT of fluid. Do any of the brakes "grab?"
Click to expand...

I expected to find some "sheens", like a shining sun. None. Nowhere. They do not grab. :-S
 
67Dart273 said:
Fluid HAS to be going somewhere. Look carefully at all 4 tires on the inside. Fluid normally will form a "sheen" --when rolling--or streaks when stopped on the tires. You should be able to see around the cylinders with drums removed.

Every 200m is a LOT of fluid. Do any of the brakes "grab?"
Click to expand...
I agree, a lot of fluid. What about the plunger inside the firewall area. Leaking down inside?
 
^^THIS^^ With that amount of fluid I'd think you would smell it inside the car
 
67Dart273 said:
^^THIS^^ With that amount of fluid I'd think you would smell it inside the car
Click to expand...
My dart sat for 4 years. The mc seeped inside the car. No smell at all. But there was liquid and gummy desolved paint under the OEM carpet.

I too have the same situation but I can positively say it is my right rear wheel cylinder leaking. Down 1 inch of fluid small resivour in a few months. Mut have just started as in Jan or March I was under the rear and would have noticed it.

The front and rear sumps are connected bya gap between the pistons so you can have a front leaked that will drain the rear sump. Something to look for.

IIRC front brake mc piston closed off a port between rear brake piston when you apply the brakes. The fluid between the two pistons is what applys the rear brake piston. In the event of a front brake failure the two pistons will touch applying the rear brake piston.

I believe that the port I am thinking about can pull fluid from one resivour to the other. (Just not 100%sure about that.) Internal leaks can for sure.
 
Is the outside of the master cylinder damp? I had one that leaked slowly, it was a rebuilt unit, still only a year or two old, I tried replacing the rubber gasket on the top but it still leaked, was always wet on the exterior, ended up replacing it again, problem solved.
 
67Dart273 said:
AND NOW AN ANNOYING story from the old days.

Naval Station Treasure Island, 68-69, going to Navy ET-A (electronics) school. I "fell in" with a new friend who later would be the original owner of.......and sell me.......my 70 RR 440-6 car. At the time he had a 65 Chevelle with a 350/ 4 speed and Ralley wheels swapped from a nearly new wrecked 67 Camaroo

Anyway he HAMMERED that thing, much to my delight. One day, He and I and a friend of mine exited TI towards San Francisco. He would the @#$%^%@ out of the thing in 1st (220 low, 3.08 rear) and slammed it into second. WHAM!!! BLAM!!! NO THANK!!! YOU!!! MAN!~!!

So we slid (rear locked) into one of the bridge emergency cutouts and jacked it up onto the spare tire, and pulled the rear cover (10 bolt) and fished out the pieces. Some funny "clips" fell out. Neither I nor my buddy knew what THEY were. Put it together, here comes the tow. He has a NICE big rubber bumper. We tell him "We think it will roll" and he is going to push us off the bridge.

So he gets us up to a "safe" speed and we take the first long, sloping ramp off the bridge, and NOW BOTH REAR TIRES are rubbing the fenders because the C CLIP AXLES have come out!!!! Bear in mind this is a 65 BEFORE THERE WERE tandem brake systems!!!!!

George taps the brakes, and thought really really REALLY fast (he is no dummy) and HIT THE LINELOCK and stabbed the brake just enough to get pressure into the front and to hold it. So the car finally slowed and stopped at the bottom of the ramp.

George, the "guilty party" at the Treasure Island amateur radio club. No idea when this was taken, as he went to "A" school at some point and later, when I met him he was an E-5 going to "B" school

View attachment 1715601088

George after he learnt hiz'n lesson. This was taken in 70 when the car was new. We had been to Lions where he trophied in PS That is the one car I wish to hell I still had, although the original 440 "left us"

I was stationed at NAS Miramar, San Diego, he was on a ship in port at Long Beach

View attachment 1715601089
Click to expand...

I've always thought that was the coolest picture.
 
Dart/Valiant said:
I managed to put the drums back on, but one thing leaves me confused. I can't find a leak anywhere, not a big leak, but the front part of the master cylinder is slowly draining. Every 150 or 200 miles, especially in city driving, I have to adjust the level. Internal leak? (no power brake to suck the fluid) At some point, the liquid should be able to escape somewhere!?
Click to expand...

I bet the master cylinder is gone. Follow where the pushrod comes through the firewall and pull back any insulation around it and I bet you'll find it. I've see insulation and carpet soak up two or three master cylinders full.
 
The rubber lines fail too. There is one between frame and rear axle. It can drip to the ground.
 
Yes the outside was a bit damp, fluid was slowly leaking on the firewall, absorbed by the dust and dirt. Master cylinder replaced, problem solved! New brake fluid everywhere, new rear cylinders, brake lines and flexibles inspected. The car will be safer.

missing linc said:
Is the outside of the master cylinder damp? I had one that leaked slowly, it was a rebuilt unit, still only a year or two old, I tried replacing the rubber gasket on the top but it still leaked, was always wet on the exterior, ended up replacing it again, problem solved.
Click to expand...
 
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Dart/Valiant said:
Yes the outside was a bit damp, fluid was slowly leaking on the firewall, absorbed by the dust and dirt. Master cylinder replaced, problem solved! New brake fluid everywhere, new rear cylinders, brake lines and flexibles inspected. The car will be safer.
Click to expand...
thanks for the resolution. Too often, we never hear the end of the story.
 
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