Semi brakes

Thought sure I released the tractor brakes. Man they sure stink when they catch on fire.The smell followed me into the house. LOL. Never had this lovely experience before.They released after I got the fires put out. Will they be o.k. to use now? They are auto adjust. Hope the water didn't crack the drums.TIA,bob

If you get inspected by DOT and they find a leaking wheel seal...might be wishing you had at least torn the brakes down and checked closer. I wouldn't want to drive far/fast/heavy with that.

My humble opinion...

Rick

no not usually, if they actually caught fire you cooked the wheel seals, brake linings and probably weakened the brake shoe return springs at the minimum, i would replace the drums too,as they are probably heat cracked or heat damaged and the fact that you were able to drive with the tractor park valve out means your auto adjust slacks were not working right to begin with, mine try to "get another notch" when possible if the brakes are applied with over 40 psi, which is a normal stop

If you could move the truck with the brakes set then the brakes wern't all that $hit hot to start with...
Time for a teardown and see what's wrong. You either had bad maxi's, poor shoes or non functioning slacks to start with. Now you've probably got cracked shoes/drums with them...

Rod

Bob
Ditto on what ericlb said. If you were able to move at all, the auto-adjust slacks weren't working, the linings were worn beyond service life, or both.
Time for complete brake rebuild before next trip. Drums, shoes, return springs, seals are damaged by the heat.
Much less expensive to do it now than have a service truck come out to the weigh/inspection station.
I have seen complete brake jobs being done at weigh station, all 10 hubs. Imagine the price to have a service truck come out, dis-assemble everything to see what is needed, go back to town to pick up/order out & wait for parts to be shipped in, then go back to put everything together. Besides that, your customer is unhappy that his freight is a day or three late sitting beside the road.
Worst of all, consider the possibility of a bad wreck caused by bad brakes.
End of rant.
Willie- diesel pilot retired.

Just a comment about slack adjusters not working. I have been a truck mechanic for thirty years, us old goats are mechanics the young ones are techs. I have found that older, more experienced drivers brakes are usually out of adjustment because they back up with minimal use of the brakes. This is when they self adjust. New drivers brakes are usually super tight. Also in alot of applications, farm hauling for sure, you don't back up enough to keep them adjusted. you must apply the brakes while backing for them to self adjust.

More of what is said below. Iff you were able to move the truck with the brakes set, you had issues long before the brakes got hot. Brake parts arent expensive when compared to the alternative. I"m in my 34th year in the trucking business and learned many years ago that brakes and tires are not the place to cut corners.

when i first got a cdl was told that if the spring brakes are on the bus wont move and if you are going down the road and spring brakes come on,the wheels would lock up..well,one day i was going about 35 and applied the spring brakes,i came to a stop very slowly with no wheel lock up.

WWe always after hooking to trailer pulled up an pulled down trailer handle an it was to make sure pin was locked an also trailer brakes better stop forward travel pronto or it was a trip to shop before traveling. Also couple years ago safety guy gave us a hard time about hard braking. Turns out the readout taken off computer every 30000 miles was tracking what we did when hooking up.We also had a card we caried that left driver adjust brakes if need to.

Reminds me of the time I saw a huge tour bus with the brakes on fire, drivers scooping water out of a creek with what looked to be a passengers luggage to put it out before all the plastic caught.

He had just come down the last grade on the way from Lilloet BC to Pemberton. I think it was over 10 km of 10% grade? The speed limit for trucks was 15 km/hr. Some short parts of the trip were 16% grade if I remember right.

You must be dealing with a different type of slack that I'm familiar with because the Haldex that I have adjust based on rod travel. When they get out of adjustment and the stroke gets longer they manage to push the adjuster rod further into the slack and get another click on it... thus turning the S-cam. Has absolutely nothing to do with direction of travel or indeed any travel at all.
What does bugger these up is the mounting angle. IF they do not achieve the correct release angle tey never come far enough back to catch the next cog and the won't adjust. Clevis angle and chamber mounting height are critical. Too short of a rod will lead to overadjusting...

Rod

Have been seeing locals here hauling 2 wagons of grain behind pick ups to town. Probably 900 bu @ 60 lb per bu= 54000lb. Hope they dont hit anyone grrrrrrrrrrrrrrrrrrr!!!!

I've never driven trucks with air brakes, but I did spend 6 years as a DOT Inspector. Automatic slack adjuster still need attention. I don;t know how many guys I put OOS for brakes out of adjustment that tried to use the auto adjusters as an out. Just doesn't work that way. Do yourself and your wallet a favor and read the manual on the adjusters and learn what the manufacturer says you should be doing.

Ive had mine on fire going down a mountain before,and they were no good after that.You could pull the buttons and it would roll off with the brakes adjusted right.It glazes the shoes and then they wont stop you.

Ive used a whole fire extinguisher on one before and barely got it out.With the old slack adjusters if it wasnt blazing real bad you might be able to slide under there with a wrench and back it off then drive down the road and the wind would put the fire out
in a couple of miles.Ive done that before.You can set the wheel seal on fire and then you are in bad shape.Ive seen trailers burned up a lot of times,especially in the winter where it got on fire and then caught the wheel seal on fire and then it caught the trailer on fire then the cargo.

Since you got the fire out you may have got lucky as long as you dont have any seals leaking now.You probably should get a flashlight and look at all the seals and see if any are leaking.If any are leaking you better fix that right now and if you can pull the drums without pulling the hubs you need to pull the drums and put new shoes on there.

There are some auto adjust slack adjusters that you have to use special grease in or they wont work right.Look up what kind of slack adjusters you have and clean them up and see if you can get them working while you have the brakes off.They get rusty or somebody that doesnt know what they are doing can mess them up trying to adjust them.

Measure your drums and look them over good for cracks and uneven wear.If they are still good you can turn them maybe if you can find a shop that turns them.If they are smooth you can skip turning them.Even if they are a little rough you can use them as long as they arent wore out.The new shoes will just wear in the grooves.You will probably have to adjust them a few times to get good brakes though.

I saw a cement truck that happened to a couple of months ago.He didnt have them on fire but he was shooting water on them from the tank on his truck and it stunk like they had been on fire.He had a cloud of steam higher than the truck and it looked like it was on fire.

35 years driving and 12 years managing (safety director) You need to replace the drums, and shoes ABSOLUTELY! Also check all air lines in close proximity to the brakes which were on fire. The drums are very likely crystalized, and will likely continue to crack, and pieces could come out and cause someone behind you to have a serious accident. At any rate crystalized brakes will fail, and usually at the worst time. Save your own life, and the lives of others, and change the components.