Brakes got overheated

[fxdave]

while getting towed last nite they over heated my brakes good my better judgement is saying to replace seals and shoes how much can they take ? and yes im after the towing company also

[Ray,IN]

Sounds like the tow truck operator forgot to hook-up the air line from wrecker to MH. That can get expensive, shoes, drums, bearings, seals, S-cam and linkage, etc.
You might get an evaluation/2nd opinion from a HDT repair shop(not only the towing company shop).

[fastcat]

They can take a lot more than you might imagine. That said, the tow company should do the right thing and have everything inspected.

Were they smokin' hot, as in red glow from the drums?

[fxdave]

Originally Posted by Ray,IN

Sounds like the tow truck operator forgot to hook-up the air line from wrecker to MH. That can get expensive, shoes, drums, bearings, seals, S-cam and linkage, etc.
You might get an evaluation/2nd opinion from a HDT repair shop(not only the towing company shop).

Ray i m not taking chances but what is a s cam ? the repair shop is a truck shop i had a broken fuel line what is a hdt repair shop ? thanks

[fxdave]

Originally Posted by fastcat

They can take a lot more than you might imagine. That said, the tow company should do the right thing and have everything inspected.

Were they smokin' hot, as in red glow from the drums?

they werent red that i could see but they sure were smokin

[FIRE UP]

fxdave,
An "S" cam is just that. It's shaped like an "S" and, it's on a shaft that rotates. Sitting against the "S" are the rollers that are in contact with your brake shoes. As the S rotates, (it rotates via a shaft from the air brake cans) the it moves the rollers and also, the brake shoes. They in tern, move out towards the brake drums. Now, all this movement, is quite slight. It doesn't take much rotation of the S cam to move the rollers which move the shoes.

That is of course, if your brakes are adjusted correctly. But, that's a whole 'nother novel. Anyway, hope this info helps some.
Scott

[Ray,IN]

fxdave, the "S" cam is the piece that applies pressure to both brake shoes when the brakes are applied, and pushes them against the drum. I'm not saying it is damaged, just needs inspection with the rest of the brake parts in that picture.

[t55watson]

Once upon a time I smoked the brakes on a rig (drums). When I pulled the drums the inside wear area had a lot of real fine lines in a honeycomb like pattern. Someone who knows more than me said that it was heat stress cracking. On a commercial vehicle they would have to be replaced. I ran them, with new shoes, for another 100,000+ miles. We don't come close to stressing the brakes or running gear the way a truck does.
Check the drums and do what feels good for you.

[MSHappyCampers]

Originally Posted by Ray,IN

Sounds like the tow truck operator forgot to hook-up the air line from wrecker to MH. That can get expensive, shoes, drums, bearings, seals, S-cam and linkage, etc.
You might get an evaluation/2nd opinion from a HDT repair shop(not only the towing company shop).

I'm not a mechanic but it sounds like Ray is right!

[palehorse89]

I read yesterday of your fuel line failure, Bummer , I am surprised if your air was down , and the tow truck did not hookup and air your system up , that he even got it to roll......the maxie brakes would of been set, not allowing it to move at all.......60# or below, brakes on. Did he take your drive shaft out or the axles BEFORE TOWING IT? If not, I would direct my concerns to the Allison........$$$$$$ but not forget the braking system.

[fxdave]

Originally Posted by palehorse89

I read yesterday of your fuel line failure, Bummer , I am surprised if your air was down , and the tow truck did not hookup and air your system up , that he even got it to roll......the maxie brakes would of been set, not allowing it to move at all.......60# or below, brakes on. Did he take your drive shaft out or the axles BEFORE TOWING IT? If not, I would direct my concerns to the Allison........$$$$$$ but not forget the braking system.

yes he disconnected the drive shaft

[palehorse89]

Originally Posted by fxdave

yes he disconnected the drive shaft

Great to hear this part anyway........

[fxdave]

still never figured out why the brakes come on

[palehorse89]

When the driver released the brakes......to tow it the air pressure was up enough to release the spring brakes.......You never mentioned if the driver ran a air line from the tow truck to the Coach, to air up the system while towing it? if not, when the air pressure dropped to approximately 6o# the rear brakes came on....... by a low air pressure condition, just as they are suppose to do.


http://www.gonefcon.com/trucktcom/b_chmbrs.htm


Better explained

https://www.youtube.com/watch?v=QVJSFlp8Pws