The Stovebolt Site Forums The Shop Area General Truck Talk Overheating Brakes?

Back in early 2010 I had Lucille's Huck brakes relined and all new SS lines, cylinders, return springs, etc installed. I had a local company burn off the old pads and then bond new pads to the old shoes. Thing is, I've got great brakes when they are cold, however, even though I feel that they are adjusted correctly with just a small amount of drag, the rear drums are overheating and locking up after about a 20 mile run. Especially the left rear. My gut is telling me that the new pads are a bit too thick. I don't have much room for adjustment. The star wheels on the wheel cylinders are turned all the way in. I don't know if it's the old backing plate not allowing the brake pads to move properly or what. I mean those return springs are unbelievably strong. So, my question, is there an easy way to just sand down the pads? And secondly, is there a material that I can apply to let those pads move better against the backing plate?

It's a pain to know that those rear brakes are heating up and having to pull over on the side of the road for a half hour to let them cool off!

Most likely its the emergency brake cables adjusted up too tight & holding the shoes off the anchors. Its also possible the master cyl. pushrod is not adjusted correctly. It should have a little bit of play before it starts pushing on theb piston. It possible the shoes are too thick but if they are free when cold generally they dont drag like that. They are probably too thick at the edges. You can tell by the wear pattern. You can sand them down some. Wear a respirator if you do. There may be asbestos in it.

Thanks George, I'll check those areas out. Maybe it's a simple fix.

I t would be easy the take the drum to the local parts house and have it turned 0.01 or 0.02 to get the clearance. Usually it costs $10 and you don't have to take the shoes off. Same would apply to rotor.

turning the drums won't always make the arc better. If the drums have been turned the shoes may need to be arced to match the drum. what happens is only the center part of the shoe will contact surface area or the ends of the shoes will contact. when you arc the shoe the entire brake surface on the shoe will touch the drum.

I am aware of the arc problem. I was referring to the overheat and lack of adjustment range. I like the e brake adjustment. Hope it helps
Had that problem myself.

If it were the push rod on the M/C being out of adjustment he'd be heating on all 4. I'll bet he needs to rebuild the pistons on the rear - he didn't mention doing that with the brake job - but I'd check the ebrake adjustment first.

Wrenchbender and all,
Well I'm slowly getting there. Both rear wheels are off with the truck being on jack stands. When I pulled the rear drums off the star adjusting wheels were almost outside of the wheel cylinders. Well, I said, that's not right! When I thought about it for awhile and figured out that the brake fluid was not returning back to the M/C. One thing I confirmed is the M/C push rod is not adjusted properly because the brake fluid if not allowed to return. The compensating port is blocked. I'm still trying to figure out exactly where the push rod adjustment should be. First I screwed it "into" the yoke that attaches itself to the brake pedal. Fantastic! Break fluid flowed back into the M/C! I then went back and adjusted the star wheels and got them in the position I thought they should be. Put the tires back on the truck and rolled her out of the garage and "wham" no breaks at all!! Brake pedal goes to the floor!!

So, what in the world is this all about?

Pushed the truck back in the garage, pulled the wheels, etc. Most everything looked OK. Made a few more adjustments with the star wheels. Then I thought it must be the adjustment on the push rod at the M/C!! Maybe I went the wrong way? So this time I unscrewed "out" of the yoke and low and behold I start getting brake pedal resistance! So right now I've put the brake drums back on, held with a couple of nuts, and the brake pedal moves about 4 inches before I can truly feel the resistance. The pedal finishes out about 3 inches from the foot board. There is no information I've been able to find about just where this push rod should be adjusted to. Do I stop at where I have it now? How can I determine if the brake fluid is flowing back to the M/C? Can I just simply remove the M/C cover and watch the fluid move or do you have to have the cover on in order for the M/C to work properly?

I do understand that brake fluid must be able to move back and forth in the system otherwise your going to overheat and lock up!

It's just this question of master cylinder push rod adjustment and just where it should be? I've also figured out that those star adjusting wheel cups have to be up against the wheel cylinder casting. For me it's so much easier to adjust those wheel cylinders and brake pads when the drums are slipped on and off to get a decent slip fit.

I'm getting there. Just need some advice on whether I'm on the right track? Wheels on, wheels off, wheels on, wheels off....that gets tiring for an "Old Guy"!!

First did vyou replace or rebuild the master cyl. If you did not or if you rebuilt it there is a tiny hole in the rear port in the reservoir into the cyl. If this hole is plugged up it will cause problems. If you have a new master cyl. disregard this. If not poke a tag wire through it. The push rod should be adjusted so it has just a tiny bit of play before it starts pushing the piston. You can tell best from underneath. Adjust each adjuater on each wheel till you get a heavy drag & back it off about 4 notches. Remember all the adjusters are right hand threads. When these brakes are right the pedal barely goes down. You just apply pressure to it.

George,
The M/C is NOS. Came out of South America if I remember correctly. Everything else is new. New SS brake lines, wheel cylinders, brass connection blocks and new brake pads bonded on.
Tomorrow I'll play some more with that push rod. I'm unscrewing it out of the yoke and with a few more turns maybe I'll get that foot pedal up higher. Is there any way to easily determine if the brake fluid is returning to the M/C reservoir? Otherwise I'm concerned that my overheating issue will return.

I'll also double check all the wheel cylinders and try to get the right drag on them. Man-O-Man, it's all these "little" details that you have to look at!! Whew!

I seem to remember watching the open top of the cylinder when I was bleeding the brakes on my 3600. When the brake pedal was released, a small jet of fluid would come up out of the reservoir... If I released too quickly, it would actually spew over the side of the reservoir.

I've got my brakes working again. I was able to adjust the push rod on the M/C out as far as I dare go. Seems to me that there is probably only about 1/8 inch of threaded rod left that screws into the yoke. I tightened the locking nut good. I also noticed that I had too much brake fluid in the reservoir and sucked some of it out with a bulb squeegee leaving more of an air space. I got the brake pedal so that it is 8 inches from the toe board and when it is depressed it hits resistance at 6 1/4 inches. A 1 3/4 inch travel. That's the best I can do considering the length of the push rod. I went for a little spin and the brakes are working fine. I will have to take her out for a stop and go run for at least 20 miles to see if the brakes overheat again. For the most part I feel that the star adjusters are close to where they are suppose to be. We'll see just how "cool" the wheels stay after a lengthy run.

The other thing that I wonder is if I truly have the correct original M/C push rod? There were other owners of this truck and who knows if I have the correct push rod. On a stock '46 does anyone know what the correct length should be? It's amazing when you look at all the dimensions that come into play to make this brake system work properly. If just one item is off you've got a problem.

That doesn't seem right. Can you wiggls the rod going into the master cyl. You should be able to. You may be depresing the master cyl. to get a good pedal & as soon as you drive it they will heat up. Make sure you have little play in the push rod & then recheck the brake shoe adjustment & bleed off any air. If those brakes are right you should have a real high pedal.

This morning after carefully inquiring about "safely" putting Lucille up on four jack stands, which ultimately happened, I removed all her tires and drums to inspect the entire brake system. So much easier to do it this way. I did find that both front brake adjustment wheels were not resting on the wheel cylinder casting and the adjustment was totally off. The adjustment screw attached to the star wheel was totally screwed "in" in some places. The rear brakes were adjusted pretty close to where they should be. I got the front brake adjusting star wheels up against the wheel cylinder casting, like they should be. Then I went around and further adjusted the fit between the brake drums and shoes until I felt that they were as snug as I dare make them. You know, spin the drum and feel a slight drag on each one. Then I adjusted the push rod on the M/C so I could feel it wiggle a bit. It was too tight. My wife helped me bleed the rear brakes. No air at all. In fact I don't think there is air in the system because I don't get a spongy pedal. I didn't bleed the front brakes. I didn't have a metric wrench to fit the front wheel cylinder bleed valve. Don't know why there is a 3/8 inch bleed valve on the rear wheel cylinders and some metric size on the front??
OK, after all this monkeying around, the brake pedal height from the toe board is 7 1/2 inches. I don't get a hard pedal until it is 4 1/2 inches from the toe board. I don't understand. Is it just because I'm making adjustments when the brake system is cold. I'm thinking that when the brake system heats up the hard pedal will be higher. Right? I'm confused about where to go next.

I'm not the brake expert, but would think that you want some free play in the peddle. Also 4.5 inches above the floor with a good peddle that does not bleed down is not too bad.

Also, are both adjusters working correctly? I have a 1950 3600 but think the brakes are the same.

I had this same problem on my '51 after I took it in for service one time. There was something screwed up about the master cylinder when I got it back. Drove me crazy for a few months with the same symptoms you mention. It had already been rebuilt numerous times, so I ended up buying a new one, and all was good after that.

I know you have a NOS one, but maybe it would be worth taking it apart and checking it out.

Kurt

Have you measured the drums to see if they have been turned to much, making them bigger?

The "star wheel adjuster" caps must always return fully seated on to the end of the wheel cylinder. If they are not doing that, you have a problem.

Lucille’s brakes do not overheat anymore! This past weekend my wife and I took her out for a 30 mile round trip drive, in stop and go traffic, from our house to downtown Greenville, SC and back. She ran beautifully in the brake department and also the engine had good power, idled well, the best she has performed ever. Just prior to our little run I had thrown the timing light on her and did a final tweak. Bingo, we’ve got a smooth running Stovebolt, finally!

I want to take a moment to thank all the folks here in Stoveboltland who have helped me over the years. I could not have accomplished what I have without all you good folks.

When we acquired “Lucille” in the fall of 2007, she was functioning poorly with a multitude of issues. A long list of deferred maintenance needed to be attended to. It was going to take time, money and knowledge. I had the time because I’m retired. The money came in bit by bit because I wasn’t going to whip out a credit card to pay for all the needed new parts and I had to do the work myself. I don’t think there are many folks out there that can afford to pay someone else to do all this mechanical work. The big thing I was lacking was knowledge. Over time I was able to solve problems with the guidance of many people here at Stovebolt.com. I am very appreciative for all the help I received.

Lucille’s Huck brakes were one of the major problems that “had” to be dealt with right from the beginning. I barely had any brakes at all. I had messed around with brakes in the past when I was younger, but never worked around this older type of system. I’m pretty confident when it comes to taking things apart and putting things back together again. So I decided I’d buy the best replacement parts I could find and redo the whole brake system keeping the Huck style in place. New relined brake shoes, wheel cylinders, return springs, S/S brake lines, new brass connection blocks and an NOS master cylinder. The installation of the new parts went very well and was leak proof with no air in the system. Where I had a difficulty was all in adjustment. Totally lacking the knowledge of how all these parts related to one another. Thus the reason for this thread called “Overheating Brakes”.

To sum up what I have learned in dealing with Huck brakes there are four major areas I’d like to point out for any one out there reworking this kind of brake system with new parts. This all has to do with making the correct adjustments to the star wheel adjusters/screws, the M/C push rod, brake fluid level and the emergency brake.

First, the star wheel adjuster cups must always be in contact with the wheel cylinder casting when you’re not braking. The star wheel adjusting screws should be adjusted so that it pushes the brake pad out to slightly rub against the brake drum. The drum should be able to be turned by hand with hearing rubbing noise. I was lucky that I didn’t have to replace all my brake drums since there was no sign of scarring or deep grooves.

Second, is an adjustment to the M/C push rod. I can give thanks to George (aka Wrenchbender Ret) in pointing is little gem out. The push rod is connected to the brake pedal and should be adjust so you can feel it “wiggle” where it goes into the M/C. I was able to do this; however, I was not able to get the real high pedal as George was looking for. There is still a little play in the brake pedal before it becomes a solid hard pedal. I’ve got excellent braking with no overheating. I’m afraid to tighten up on the star adjusters any more worrying that they will be too tight.

My third point is to make sure you don’t over fill the M/C with brake fluid. Leave a small air space so the fluid can modulate back and forth in the system.

Fourth, check the adjustment on the emergency brake. You want to make sure when it is fully retracted, (off), that you’re not putting a drag on the rear brake drums.

So, it’s been a long road and finally I’ve got Lucille to a point where she is a joy to drive. I’ve got one more test I’d like to put her through and that is a hill climb near where I live that goes for about 10 miles from elevation 900 feet to 2100 feet! If she’ll do that I’ll be on top of the world!!