Catastrophic parking brake failure

[dave wagner]

Maybe time to look for a good used one.Kind of hard to get 2 bad NOS parts .Are you doing something you shouldnt be ?best friends wife,robbing banks,stealing social security checks from mailboxes?Just kidding,that is some kind of bad luck.Be thankful you didnt injure yourself or someone else.Good luck on your project

What are NOS parts? Only one of the new brake drums had a crack also.

 

[rosco]

"new old stock"

 

[butch atkins]

brake failure

BTW when i got my truck from the fire dept it also had the drum explosion,completely missing ,along with the "ear" off of the retainer (the part on the end of the TC that all of the parking brake assy bolts to.I had to replace the entire assy because of this.Kind of late to mention this but you should also very carefully inspect this component ,cause it sure looks like this could have happened to yours.I STRONGLY URGE ANYONE WHO HAS HAD THIS HAPPEN TO LOOK AT THIS COMPONENT ALSO. I replaced mine with a used unit off of a parts truck that WHITE OWL PARTS had in their yard. If anyone needs to replace this component,I have 2 NOS units for sale.RETAINER part# 7411361,pg 263,ORD 9 SNL G-749,I usually reference parts out of the TM 9-8024 ,but this is not covered in this TM.It is not a hard job and is the perfect opportunity to inspect the rear brngs for the driveshafts,and replace those leaking rear TC seals.Should have rememberd this earlier ,but i am 55 yrs old and cant remember what i had for breakfast.LOL.Voice of experience speaking here,so dont let this slip by next time you are doing a visual insp. under there.Good luck to all on your projects

 

[dave wagner]

If you look close at the first picture I posted you should be able to see both ears were broken.

 

[paramedic7831]

Might you have left the the E-brake engaged when this happen?

 

[Gunfreak25]

The part with the "ears" is called the handbrake band support and mine had the ears broken off and rewelded back on by a previous owner or the Military. Butch has the part number for this item correct as confirmed by the Levy parts book. This item is $100 from Alfa Heaven and is not at the top of my to do list but will eventually get replaced. It does look pretty easy. Chain yoke to frame to keep from turning and use breaker bar with socket on the yoke nut. Splined yoke should slide right off or with some heat.

These GMC's are not getting younger! I am also having my drum magnefluxed. Crap load of rotational mass there!!!

 

[targhee trucks]

Excellent post and followups. Thanks to all.

Just added "check e-brakes" to the lists for all the trucks.

Jack

 

[redthegreendog]

My m211 was a fire department brush truck.
It was missing the E-brake when I got it.
I will be doing a rebuild after I replace the wiring harness.
Will be having my new drum magnifluxed when I get one.

 

[OPCOM]

On the M35A2, the parking brake might stop the truck in an emergency, sort of a one time use. but it won't stop quickly and there may be a fire once it has stopped from a high speed. It's not for that.

I'm more interested in finding out how to avoid loss of brakes from a single blown air tank. And maybe how to test an air tank, preferably in place. And how they are inspected, or how to inspect them. The ones on my M818 seem to be a little thinwall for my liking but they do not seem bad nor has rust ever come out of them with the stopcock water.

Who knows how to inspect a tank or test it?