Quick! Help! Sticking brake!

[Bamamav]

I have a front brake sticking and getting hot. Got so bad this afternoon I had to open the bleed valve to get it to release. It has always pulled to that side when you hit the brakes and has stuck before but never this bad. I thought it was the shoes might have something on them but they should be clean by now. It acts like fluid is not returning to the master. I am going to take the residual pressure out when we get home to see if that helps. Know of anything I can do right now? I tried leaving the bleed valve loose, that didn't work, it just made the front brakes not work. The years are not working right either. I have to give them a look as well when I get home. When I had the front bleeder cracked the rears didn't hold it in drive may just be adjustment on them.

 

[Bamamav]

Sorry for misspelling phone did auto correct .

 

[Sniper]

The first thing that comes to mind would be a pregnant hose. Any soft spots, kinks, or bulges? A broken or missing bottom spring that goes from shoe to shoe will allow the shoe to self energize and apply. You mention shoes, so I'm guessing drum brakes. If shoes get contaminated with brake fluid or grease it will dry out some and get real sticky and grab. I've never had much luck with "cleaning" shoes, the oil/grease will leach out of the pores when they're hot and get sticky/grabby again.

 

[Bamamav]

Lines are new braided steel. Shoes were on car when I got it, were a whiteish gray color but looked like no wear on them. All hard lines new, have corvette style master cylinder also new. Two lb residual valves in both lines at master. All original hardware in front brakes except new wheel cylinders , everything new in rear brakes. 12" drums in front 10" drums in rear.

 

[smallfoot]

If you have enough slack in your lines, you might try eliminating the residual valves. I'm running full manual drums all around and took them out of my system without any problem.

 

[fuzz]

In a drum brake system where the shoes won't return it seems the return springs aren't doing their job. Look for wear or rough spots on the backing plates that might keep the shoe from returning.

 

[Yankee Transplant]

Im no expert but if you release the bleader and fluid comes out your springs are doing their job Id say collapsed line I know you said they were new , but the rubber may have a defect inside... your foot will push that fluid threw a bad line but them little springs cant push it back threw to the master ,,, if it only locks up after you used the brake ,,Id say rubber line .. Ive only been wrong 1 time in the past hour.. so ...................

 

[sneakysnake]

Bad line or the pedal isn't returning to the full rest position and the plunger on master wont let the fluid back into the reservoir,

 

[Bamamav]

Locked up again today. When the drum cooled the brake released. Was advised to plug the line on that side, tried it and didn't have any brakes. The years simply are doing nothing. Unplugged the line and bled the fronts and have brakes again. Heading home in the morning. When I get home, I'm pulling off the residual valves first, and my pull the adjustable prop valve too. Also pulling the rear drums to see what is going on there. Lots of work to do. Will post a thread on my trip sometime after we get home with lots of pics.

 

[Yankee Transplant]

maybe back way off on the shoes on that side so they dont push against the drum???? and dont use them as much as possible .. can you use the E-brake for low speeds ?? be careful driving with no brakes aint worth a crap ..

 

[Bamamav]

Oh,it'got brakes, it's just when you use them a lot like in town that they start sticking and eventuality lock up when they get hot. When the drum cools they will release . On the highway they are fine, you don't use them so much and they don't get as hot. That's why this hasn't popped up before, All my driving has been on the open road not in traffic in town.

 

[Old Iron]

The pedal has to have free travel of about 2"
If the rod from the pedal to the master doesn't have a little slack it'll do this.
If it has power brakes, there has to be the same clearance between the booster plunger and master or same issue.
Ask me how I know

 

[Sam_Fear]

If it's only doing it when the brakes are hot, I say it's an issue with boiling fluid at the slave cylinder or some other heat related problem at the slave. Like the slave cylinder itself is sticking.

Otherwise, are your front lines (steel and rubber) run along the motor where they could be picking up too much heat while city driving?

 

[Dr Crankenstein]

I also suspect master cylinder and necessary free play.

Just a thought... your pedal may need a return spring (or a better one) to insure full travel, consistent play and stroke.

.

 

[Bamamav]

Made it home! Got to get the car unloaded of suitcases and such and dig into the brakes.

First is to figure out why the rears aren't doing anything. They bleed good, but have no effect, I'm hoping it's just an adjustment problem. I thought I got them tight enough, but not leaving any stones unturned. Next, figure out what is going on in the front. Coming home, I noticed the pedal is not returning to full height every time, so it may be causing that brake to drag and overheat. After the last bleeding I have steady front brakes, no pulling to either side, but a very low pedal before it starts to stop. I'm thinking part of that is in the rears, they are on the rear section of the master cylinder which activates first, the fronts are on the larger front section [GM early Corvette style master cylinder]. There seems to be too much free play in the pedal, I think the adapter that goes between the master and booster must be a tad short, if you remember I had to make one when I put all this together as Speedway didn't put one in the pedal/master kit. I measured and thought I made it the right length, but guessing to not make it too long I may have it too short. I may call them tomorrow and have them send the proper adapter.

Another thing that has popped up is a steady clunk clunk clunk on the right rear side. It changes with vehicle speed. Not sure what's up with that, driveshaft, U joint, ring gear? Going to put it on jack stands and run it in gear and see if I can narrow it down.

Got a little work to do. Other than the clunking and the brakes, the old girl did pretty good. It did stall out a time or two while turning, may need to adjust my float level a bit, but other than that, she ran 190*, about 28 lbs oil pressure with 10-15 lbs hot idling, little low for my liking, but for a 1975 engine with unknown mileage and probably never been into, it's decent. No knocks or rattles, plenty of power. I'm pretty happy with it.

 

[Bamamav]

Well just did a post trip inspection. Not happy with what I found.

Put the rear up on stands to try and find the clunk. Found it and my vibration. Driveshaft is warped, and pinion is moving up and down, suspect it or ring gear are shot. Good thing I have two extra chunks, a 3:00 and a 3:55, not sure which I'll use, has a 2:79 in it now. I never checked the driveshaft before, it was in the car hooked up already, I have never had it out. It will have to be balanced and straightened. Found out rear brakes are working some, didn't get to trying to adjust them after I saw the driveshaft wobbling.

Another thing, my wishbone drop bracket broke. Must not have used thick enough steel. Going to do it a little different this time, maybe it will be stronger.

Decided to just park her for a while and go back and redo what needs it. May be down all summer. Oh well, that's hot roddin'. Think I will order a set of injectors for the Vette and fix it first, should be a faster fix and get back to cruising sooner.

 

[Yankee Transplant]

well at least you are finding the problems .. I swapped out an intake on my spare truck today took the high rise Ofenhouser , and Holley adapter off and put the stock steel back on it .. not done yet I'll work on it some more tomorrow .. still dont know if this will fix the staling out when ideling sometimes . this is just a guess in the dark .. its cheaper than buying a new carb , just to see if it fixs the problem .. if its still quits running for no reason.. Ill know its the carb thats just been rebuilt .