Whoa, No Brakes on 20,000# Deuce

[Recovry4x4]

How stupid can one be? Of all people I know the dangers of the single circuit brake system. Well since the M108 is running I've been driving around the block here and there. Its got a new master and booster but the wheel cylinders and brakes have not been checked. The other dayI was out on a slow cruise and when I tried to stop POW! The brake pedal went to the floor. Got home safe and peeked under the truck to see fluid dripping from the drum on the right forward rear axle. Today I pulled the tires off to have a looksee at the suspect blown wheel cylinder. Imagine my surprise when I found the following. I'll post more on it later with a few questions but WOW. Take a look.

 

[mangus580]

WOW thats pretty cool!!!

I had to look at the pics 3 times to see what you were trying to show us....

 

[Dieselsmoke]

Holy crap Kenny, glad you made it home alright!!! I've NEVER seen a deuce brake drum come apart there before!!

 

[Desert Rat]

Most impressive Kenny!!!!! I see the "ring worm" gottcha! Sure you didn't need to change your skivvies when you got home? Or was that the pucker power that saved the shorts?

 

[BFR]

brakes! We don't need no stinkin' brakes!

 

[gringeltaube]

Man, you where lucky!
I wonder if the other piston isn't frozen in the brake cylinder?

 

[jwaller]

so did it just break or did something cut into it over time and turn it like in a lathe? very scary stuff.

 

[ida34]

When I used to work at a parts store people would bring in rotors that were so thin that you could poke your finger through the metal into the cooling fin voids. Then they would act like I was trying to rip them off when I told them they would have to get new ones.

Kenny, It must be that healthy FL salt air. Are you near the coast. That looks like it would fit right in on a Michigan rusted pile of junk truck. Glad you are OK. Did you release the crane hook as an anchor?

 

[rdixiemiller]

Looks like the shoe hold-down broke on the trailing shoe and let it cut through the drum. This was not too uncommon a problem on the older cars with drum brakes, although I never saw it on a deuce or a big truck. If the hold down breaks, the shoe retractor spring will cause the shoe to push out against the front edge of the drum. Metal on metal will do it in a hurry!

 

[czechsix]

Dang, that's one for the books. Good to see you made it home OK...I'd put those drum pieces up on my wall somewheres as a reminder.

 

[rmgill]

I don't suppose you saved yourself a few extra brake drums from that rusty truck did you?

 

[Recovry4x4]

OK, heres the scoop. All 4 hold downs had let go. The return spring is on the face of the shoes so its just pulling them into the drum. No way this could have happened in the few miles I've drove the thing. The shoes ground right through the drum. When the drum finally broke through the shoes shifted farther outward and the wheel cylinder piston was pushed out. I'm not sure this was an isolated event. Remember the truck is a 1953 and the axles all depict that. The hold downs I'm used to seeing are somewhat of a shouldered bolt with a 3/4" head inside and bolt through the backing plate. This truck has 4 studs that appear to be peened into the backing plate and apparently had flat washers and cotter pins holding them on. I did find the remains of a bent up washer. I plan on knocking the studs out and going to the current shouldered bolt hold down to eliminate this problem. Maybe thats why they were changed. Yep Ryan, I did keep the rears. I stripped parts off one of the M756A2 rears. Despite how rusty the 756 was, the brake parts looked darned good and the wheel cylinders were still sealed with BFS in them. I put a new wheel cylinder on this wheel but I'll rebiuld the take off wheel cylinders from the M756 and use them. I've still got 3 more new wheel cylinders but prefer to rebuild them. I'll do the rear lines and hoses while I'm in there and fix this thing right and for good. Here are a few more angles and details.

 

[mangus580]

kenny, were you able to use the crane to lift the duals off?

 

[Polverone]

That's it, I'm puttin' a drag chute on the back of my rig.

Glad yer safe Kenny.

 

[clinto]

Wow. I don't know what to say. Glad you and the '08 are safe and sound.

 

[Desert Rat]

Kenny,

Some of the older KWs I've driven had the same set-up. The shop was too lazy to swap things around to make safer trucks so the DoT came in and told the company the trucks were shut down. I'm not sure why this design wasn't banned from production, but the military was at least thinking that way. I'm sure this old design is still in use somewhere in the US today.

At least the ring didn't shatter and take a set of tires with it. I've seen that happen before too. That's really nasty. Plus you didn't have a load on the truck either. I've seen the ugly results of the worst-case and the legalities as well. I'm relieved you didn't become another victim. This is for those of us who have the older design or are contemplating (like me) to get an older truck to convert the brakes to the safer design.

Leave it to Kenny to be the pioneer blazing us a new trail (again!!!) to safer trucks!!!! (Insert Benny Hill salute)

 

[rmgill]

Seems like an annual inspection of your wheels is in order. Gotta get my yard in order with a flat area for the lift for tires so this is a fairly quick evolution. The harder something is, the more likely I am to put it off.

 

[Recovry4x4]

As much as I know about the dangers of the single circuit brake system, I don't do enough maintenance or inspections on either truck. This stuff should be way up on the list. Too busy checking the go stuff not enough time on the woah stuff. I think I've convinced myself to install some type of vent on the master cylinder cap so that removal is easier. That needs to be checked on just about every pretrip. I've also come to the conclusion that each truck needs to have its own gallon of BFS onboard at all times. I think the distorted look from that brake failure is still on my face.

 

[rdixiemiller]

Kenny
Just grab the parking brake handle! It is also called "emergency brake"!!!!

 

[M35guy]

so.. I hear your truck is alll go and no whoa. umm, yep thats a problem to me.