Anyone running a "Pinion Brake"?? - Page 3 - Steel Soldiers::Military Vehicles Supersite

TheBuggyman · 01-08-2007, 20:22

Quote:

Originally Posted by jwaller

I don't understand why the pinion brake setup you have drags so much and creates heat when your not using it. is it somehow different from a normal disc brake? I know disc brakes do drag some when not in use but it's not an issue bc everything produced today has them.

It does not drag much at all, a hydraulic caliper exerts just a little bit of force on the pads. But remember how fast the rotor is spinning. 6.5 times as fast as the wheels!
An OD tranny with the engine at 2100 rpm will be spinning the d-shaft about 1600 rpm with a .8 overdrive and that is how fast the rotor will be spinning. Also, the pinion brake rotor is much smaller than a typical truck rotor so it cannot dissipate the heat generated as fast.

TheBuggyman · 01-08-2007, 20:23

Maybe a vented rotor? Would that help?

mucekok · 01-08-2007, 21:31

i run the usa 6x6 pinion brakes on my rockwell'ed suburban with great satisfaction. they will stop the 46" goodyears weighing in at 342# each (withwheel and beadlock) fast enough to throw you thru the windshield. and thats with near zero effort at the pedal. there is also a kit for about $145 from usa 6x6 that allows your pinion brakes to be used as a parking brake. it is only in my opinion that a pinion parking brake would work fine on semi level ground with reasonable traction just using the cable, no hydraulics. of course in a situation where traction is questionable it might send your truck rolling away with tires spinning in all kinds of directions...so chain it off to a big tree instead...or go park somewhere else...the parking brake on my duece serves its purpose...gives me something to trip over when getting in and out of the truck. even in its functional days it did not hold well enough to remind me that it was set before driving off. "hey, something's burning, y'all smell that?" what about using a hydraulic pinion brake with a line lock? and a dummy light?

TheBuggyman · 01-08-2007, 21:38

Mucekok,
Do you drive your 'sub any long distances? I'd be curious to see if the temperature levels out or will keep climbing.

mucekok · 01-08-2007, 21:47

never driven it nonstop for more than a few (5 or less) miles. have never had any problems with it getting hot. i think if everything is in correct working order it should release just like a normal disc brake. may get hot simply due to the fact that it is spinning alot faster than a wheel brake. maybe use a vented and cross drilled rotor?

TheBuggyman · 01-08-2007, 21:55

The longest that I drive my buggy is down in Tellico, maybe 5-7 miles but only at about 25 mph and my rotors get REAL hot. They don't glow but you cannot touch them either. I have the USA6X6 kit too and have solid rotors.

73m819 · 01-08-2007, 23:31

Bjron, true about on the slope with a strandard ebrake, but i have delt with some loaders that weigh in about 45000#, thay have a disk ebrake we had to release the ebrake by hand to move them , also some heavy trucks, the same, these disk ebreaks hold the heavy iron even on a steep grade. true in muddy slope conditions about nothing is going to keep the trucks from sliding, other then that in normul conditions, why not

ive seen disk ebrakes in both hyd. , spring, and air set, the hyd. setup needs a accumulator to set the brake in case of loss of hyd. pressure, also hyd., spring, and air release, most of the systems had a combination . i realy dont see why such a system could not be built for our trucks, a big disk mounted where the drum ebrake is now ,not a little disk but a 16" or so, with its own master cylinder, using a trucks air spring brake can to activate it, no air for what ever reason , the spring brake sets which it turn works the master cylinder and sets the disk ebrake. this all would happen in less then a second, spring or air could be used as a pull back release once the air spring brake has pressure. the air spring brake can/master cylinder combo could be mounted in the frame with just the hyd. line running to the calibers and a air line if air pull back is used

OPCOM · 01-08-2007, 23:42

so if someone is driving 300 miles on the highway, a pinion brake may not be a good idea?

73m819 · 01-08-2007, 23:47

WHY, if its set up right there SHOULD NOT be any drag at all

TheBuggyman · 01-09-2007, 09:57

Installing the brake/caliper/master cylinder is not a problem and putting it in place of the existing parking drum brake is an excellent idea. All I need is for someone with more knowledge than me of hydraulic disc brake systems to tell me how to pull the pads COMPLETELY off of the rotor. 73m819, you mentioned an air pull back. How would that work? We already have air, this may be the solution.
What is it that keeps the slight pressure on the pads? Is it the spring inside the MC? Is that spring just for piston return in the MC? Maybe a cutting brake setup to force fluid one way and pull it back the other?
All disc brake pads rub the rotor during operation, Maybe it is just as simple to use a large, ventilated rotor as 73m819 suggested, would it handle the excessive rpm and subsequent heat generation?