Deuce brakes marginal?

[cranetruck]

Why do you consider the service brake system on the M35 deuce marginal?
The air over hydraulic system provides close to 2,000 psi of pressure to the wheel cylinders. The brake drums weigh about 80lb/ea and can each dissipate up to 12 KW of heat.
I have never tried to lock them up, but probably could.

Braking distance is a function of traction, which is a function of total vehicle weight and distribution of the load on the axles/tires.

Is it just a matter of adjustment?
Anybody ever measured the stopping distance at a given speed and compared it to another similar (commercial) vehicle?
Opinions, please.

 

[Squirt-Truck]

Bjorn,
This is a great question, hopefully we will get some response. I have just (Friday) spent all day in brake testing of a commercial 18 wheeler. Even with unacceptable trailer brakes the tractor still provided sufficient stopping power to give the accepted standard of 0.5G and this at 80K. We actually had the discussion of wondering how an MV would react. The tires have a much greater friction coeff. (NDCC's) and the system easily genreates lock-up force. The ONLY advantage straight air has is there is no fluid to get hot a boil and the air circulates in the drum better due to no closed backing plates.
I am willing to conduct this test with anyone willing to use their truck and/or provide tires to kill. I have access to the measuring equipment whenever needed. (Need 10, 11:00x20)
Thoughts guys.....

Squirt-Truck

 

[cranetruck]

So speed doesn't really come into the picture then.
Wonder if there are any low cost accelerometers out there...

 

[bomar76]

[quo

 

[cranetruck]

I'm not refuting your statement, just bringing it up for discussion, may we'll all learn something.
On what do you base your statement?

 

[Adamlee]

deuce brakes...good or no?

I am very pleased with the brakes on my deuce. They will lock up...at least on a gravel road, I have done that....and the truck stops real quick.

Pedal feel, pressure, all that...the brakes make me feel confident, as opposed to the half-ton IHC pickup I had (73) with a strong 345, an AT, and powerbrakes....on drums! THAT was not fun...those drums would heat up superfast, and I remember fooling with swapping drums and trying to make things better, to no avail...sold the truck before I ever really was happy with it...made things fun in the rain, on the beltway, in close traffic....

 

[Recovry4x4]

I've been able to seize up the brakes on every deuce I've owned that had brakes. The biggest fault on deuce brake system is the single circuit system. Its a scary thing when you reach down for brakes and get NOTHING!

 

[baja_power]

The brake drums weigh about 80lb/ea

80 lbs? not quite..

a brake drum weighs almost half that.

 

[cranetruck]

Baja, guess my memory is not so good any more, thought each drum weighed 83 lb (38 Kg). Numbers don't lie, thanks.

Mark, when I get new tires, I'd love to drive down to Marietta (?) and participate in those test runs. It could be a while, but still...

 

[rdixiemiller]

I had to jump all over my brakes a while back at 45 mph. Locked the rears without trying to. The fronts did not lock. I consider the brakes to be as good as the old dump trucks I used to drive.
I agree with the issue of single circuit brakes. That is a really bad feeling when the pedal hits the floor and you keep right on going. However, in defence of the deuce, I had an F700 ford with disc brakes lose the booster. I had 22K of bleach on the truck at the time. Talk about a scary experience stopping! I was on an off ramp when I hit the brakes and the pedal was like a rock. I cracked the steering wheel, and broke all the stays out of the seat back. Had to see my proctologist for a seat springectomy.....
My point is, you can experience brake failure in any vehicle. Proper maintenance of any brake system is crucial.

 

[spicergear]

I hate my brakes with a passion. Someday I'll have brakes again...maybe. Hate them I tell you.

 

[rdixiemiller]

Whats wrong with your brakes?

 

[rmgill]

I've locked the brakes up on my Deuce. Going down a gentle 45mph hill and realized I needed to stop for a just changed light. It was on that borderline of do I stop or do I keep going kind of thing. I elected to stop. I dragged the rear tires and launched my rather tough Apple Powerbook onto the floor from the seat. I figure that's at least a third of a Gee if not a half of a Gee. It was largely empty, but it did shift everything in the cab forwards and I got a nice smell of burnt rubber that wafted past the truck.

 

[Stretch44875]

I have locked the rears on my truck before. I can tell you that adjusting the brakes according to the manual makes a noticeable difference. I had a higher, more aggressive pedal after adjustment.

I trust my deuce brakes a lot more than my international's full air system. The full air system is more touchy, but doesn't have as much stopping power, won't lock the wheels, and dosen't stop nearly as quick.
Dennis