Not Happy

[Canadian1968CoronetR/T]

Just picked up my Coronet R/T from garage, he replaced the brake booster that fell apart inside when he took it off, he sent away to be refurbished at a cost of $379.00 plus taxes, I don't think there was anything left in there at that price. Anyway felt good to have good brakes for first time, did a little burn and left to go to grandson's lacrosse game 20 mins away, got down road about 10 mins and the car started to shake like a flat tire, I stopped got out and checked they looked ok, got back in went on into town got gas, paid came out went to move to go to arena, car did not want to move without giving it gas, I had window down I could hear rear tire dragging, I pulled across street and got out. Put my hand near drums and front discs there was a lot of heat coming off of all them , with the rear being the hottest. Had to come home get trailer and wait until Tuesday to get hold of Mechanic to find out what happen. Any you guy's got ideas, can a booster hold pressure on, I would not think all 4 brakes would stick at same time, anyway they did let go for me to put car on trailer, hoping I have not warped anything? Not having a good day. Trying to get car ready to sell, I think I have bought another Mopar, done the way I was going to put this one. How does a GTX compare to a Coronet R/T same year?

 

[ws27]

They're all the same. If all four are dragging, I bet the booster adjustment is not allowing the master to go all the way to rest position.

 

[black64]

Are your brake lights on? This would indicate if your having a problem as ws27 is saying.

 

[rrowdy]

What a bummer,
WS is correct, the master cyl has to return to the "rest" position in order to allow pressure from the cylinders and calipers to return back to the MC.
sounds like an easy fix if no damage was done.

Good luck

 

[69B5]

I have also heard that if the brake lines are too close to the manifold or header, that the brake fluid could heat up causing pressure to build up which could have the same result as applying the brakes. Just my $.02

 

[68GTX440]

Remove a brake line from the master cylinder. If you see a brass insert in the master cylinder side REMOVE it and your problem will go away.

Just picked up my Coronet R/T from garage, he replaced the brake booster that fell apart inside when he took it off, he sent away to be refurbished at a cost of $379.00 plus taxes, I don't think there was anything left in there at that price. Anyway felt good to have good brakes for first time, did a little burn and left to go to grandson's lacrosse game 20 mins away, got down road about 10 mins and the car started to shake like a flat tire, I stopped got out and checked they looked ok, got back in went on into town got gas, paid came out went to move to go to arena, car did not want to move without giving it gas, I had window down I could hear rear tire dragging, I pulled across street and got out. Put my hand near drums and front discs there was a lot of heat coming off of all them , with the rear being the hottest. Had to come home get trailer and wait until Tuesday to get hold of Mechanic to find out what happen. Any you guy's got ideas, can a booster hold pressure on, I would not think all 4 brakes would stick at same time, anyway they did let go for me to put car on trailer, hoping I have not warped anything? Not having a good day. Trying to get car ready to sell, I think I have bought another Mopar, done the way I was going to put this one. How does a GTX compare to a Coronet R/T same year?

 

[RJS]

Just sounds like the rod between the booster and master has to be shortened a little.
Brakes will drag if that is maladjusted.

 

[ws27]

Remove a brake line from the master cylinder. If you see a brass insert in the master cylinder side REMOVE it and your problem will go away.

Sorry to disagree, but be careful here. The brass insert can be just the flare cone. There is a residual pressure valve to hold a small amount of pressure on for drum brakes only. The way to tell is whether you have a disc master or not. A disc master will have one reservoir bigger than the other. If you have a 4 drum master then the discs will hang, but only for a little while. Also the pressure valve actually bleeds off the pressure after 5-10 seconds. So you could really get away with it and not really notice unless you are pressing on the pedal every 5-10 seconds. It is possible that the brake pedal returns, keeping the brake lights off yet the adjustment prevent the master from returning completely.

- - - Updated - - -

I have also heard that if the brake lines are too close to the manifold or header, that the brake fluid could heat up causing pressure to build up which could have the same result as applying the brakes. Just my $.02

This will only happen when the master is not returning. When the master is fully returned, each piston has cleared the small hole that allows the brake fluid to go from reservoir to cylinder and back. If can go both ways to accommodate the expansion you are talking about. Take a look at this:

 

[68GTX440]

I absolutly agree with you but he does have front disk. I had the same exact problem when mine was done in the 80's and this was the problem. Removed the inserts and all was good.

Sorry to disagree, but be careful here. The brass insert can be just the flare cone. There is a residual pressure valve to hold a small amount of pressure on for drum brakes only. The way to tell is whether you have a disc master or not. A disc master will have one reservoir bigger than the other. If you have a 4 drum master then the discs will hang, but only for a little while. Also the pressure valve actually bleeds off the pressure after 5-10 seconds. So you could really get away with it and not really notice unless you are pressing on the pedal every 5-10 seconds. It is possible that the brake pedal returns, keeping the brake lights off yet the adjustment prevent the master from returning completely.

- - - Updated - - -

This will only happen when the master is not returning. When the master is fully returned, each piston has cleared the small hole that allows the brake fluid to go from reservoir to cylinder and back. If can go both ways to accommodate the expansion you are talking about. Take a look at this:

 

[Canadian1968CoronetR/T]

Thanks for all the advice, as it turns out the mechanic had to turn down the plate between the master cylinder and the booster and forgot to adjust the rod. It was leaking between the booster and cylinder that was why he had to turn it down. Took it for a run, hit brakes several times seems good, I think I may feel the front rotors a little warped, but not real bad at this point. It feels good to have good brakes I maybe able to let wife down now, clear the highways.