Dual circuit brake using pinion and wheel brakes.

[Hainebd]

Is anyone doing this? One circuit to wheels, the other to pinion brakes.

 

[gimpyrobb]

The pinion brakes heat up real quick since they spin 7xs faster than the wheels. We had a debate about them a while ago and guys that put them on said they regretted doing it.

 

[clinto]

Lots of reading on why this is a bad idea:

http://www.steelsoldiers.com/showthread.php?138443-Deuce-disc-brake&p=1702993&viewfull=1#post1702993

 

[Hainebd]

Ok. Ok. Ok. Thanks. I had to ask the experts.

 

[peashooter]

I've wondered about just having a pinion brake (with a separate pedal or hand lever) to use as a last resort emergency brake in case of a hydraulic system brake failure (ruptured hose or something).
Would 1 pinion brake on the front axle (assuming no lockout hubs) or center axle be enough to stop a deuce within say double the distance that the service brakes could? I understand the brake may be completely shot after this one use, but its got to be one of the most affordable ways to have a redundant brake assuming it could do the job even once.

 

[gimpyrobb]

Peashooter, compare the size of the stock parking brake, which won't stop a truck with failed brakes, to a pinion brake. I doubt its worth it.

 

[Section8]

Not sure if it would be possible to put a larger rotor that has LOTS of venting holes in it on the pinion to reduce its melt down time.
Say a 15 inch rotor like what is used on the disc brake conversion. Just punch a bunch of extra holes in it.
It was also mentioned in other threads the ideas of a hydraulic drive line brake like some large equipment uses.
Not sure if it could be applied to a deuce but I kind of find the idea interesting.
All this being said... with a blown line or complete hydraulic failure a mechanical e brake is highly appealing.

 

[peashooter]

I've got dual circuit brakes already but most folks don't. I'm sure most people would love to have them but they are expensive and difficult to install/retrofit. I think lots of people would be interested if there was a simple system under $500 and easy to install, that could stop the truck if the hydraulics failed.... Even if it was a one shot system.
Maybe a pinion brake isn't much better that the drum parking brake? It seems to me though a hydraulic disc pinion brake would work lots better than the cable drum parking brake that has minimal mechanical advantage and a stamped drum that looks like it could flex easily? Again I really don't know and have no experience with pinion brakes but for now I'm not ready to accept that a pinion brake wouldn't work significantly better than the parking brake in a single emergency situation.

 

[Hainebd]

With the ceramic disc and pads along with 6 piston calipers it may work. It would assist and be second circuit. The big issue is not allowed on street by DOT and/MV.

 

[welldigger]

If you had a pinion brake on the front and rear most axle it would stop an empty duece.......once. The pinion brakes would then be a molten puddle of slag.

Keep in mind most pinion brakes for a rockwell 2.5 ton axle are a Mazda b series truck front disk. They aren't exactly large in diameter or thick. So they won't dissipate the immense amount of heat an emergency stop would create. But, in a shtf situation it would work in my opinion. Or at least be better than nothing.

 

[red]

Would make for a much improved E brake and parking brake over the stock drum.

 

[rustystud]

I've wondered about just having a pinion brake (with a separate pedal or hand lever) to use as a last resort emergency brake in case of a hydraulic system brake failure (ruptured hose or something).
Would 1 pinion brake on the front axle (assuming no lockout hubs) or center axle be enough to stop a deuce within say double the distance that the service brakes could? I understand the brake may be completely shot after this one use, but its got to be one of the most affordable ways to have a redundant brake assuming it could do the job even once.

Aaron check out this site. At work we had these on our older 40ft busses. They can almost bring a fully loaded bus to a complete stop. They make them for all kinds of applications.
http://www.telmausa.com/products/operating-principle

 

[Jeepsinker]

You can't put two pinion brakes on each rear axle and gain some performance?

 

[Keith_J]

With the ceramic disc and pads along with 6 piston calipers it may work. It would assist and be second circuit. The big issue is not allowed on street by DOT and/MV.

The issue is twofold, mass and cooling. Take the six drums off a deuce/five ton etc and weigh them. That is how much mass you need in the pinion discs. Plus cooling which SHOULD be easier as the pinion is turning so fast. But as nearly all pinion discs are solid, not vented, they overheat like Rosie O'Donnel in a confessional box.

The issue isn't the speed of the pinion that causes overheating, it is thermal mass. A 13k pound deuce moving at 50 MPH has just a shade over 1 million foot pounds of kinetic energy. If it takes a MINUTE to stop, that is an average of 24 kW of stopping power. That is a good bit of heat. Heat is work is energy.

Now consider a panic stop in three seconds. About 500 kW.

 

[peashooter]

The only advantage of dual circuit brakes is in the one event that a catastrophic failure of a circuit happens. Everything else about dual circuits is a disadvantage in my mind. I don't feel like they stop as well as the single circuit trucks, they have higher & more difficult maintenance, added cost for repairs, etc.
Having some redundant way to stop the truck available in a single emergency instance is all people need. That instance should never happen but if it does they are probably fine with having to replace a pile of melted slag assuming it saved life &/or property.

 

[welldigger]

You can't put two pinion brakes on each rear axle and gain some performance?

I don't see why you couldn't put a disk on each pinion flange. Keep in mind each time you add one this is more $$$$. So how many would it take to make a useful emergency brake and how much would such a system cost?

 

[peashooter]

I don't see why you couldn't put a disk on each pinion flange. Keep in mind each time you add one this is more $$$$. So how many would it take to make a useful emergency brake and how much would such a system cost?

Boyce sells a pinion kit for $300ish right so I'm sure you can easily get a caliper and disc for under $100, a hydraulic handle like below for $100 and someone to make some laser cut weldment (if it can't be flat stock) brackets.
Welldigger, Why do people use Mazda brakes? Do they just happen to have the right pattern on the disc?

 

[welldigger]

Boyce sells a pinion kit for $300ish right so I'm sure you can easily get a caliper and disc for under $100, a hydraulic handle like below for $100 and someone to make some laser cut weldment (if it can't be flat stock) brackets.
Welldigger, Why do people use Mazda brakes? Do they just happen to have the right pattern on the disc?

I might be incorrect on the Mazda/ford ranger disk. I thought that's what they told me but its been a while. It is definitely off of something that has 4 lug bolts. I do remember the disk they showed me was an off the shelf duralast rotor from autozone.

And yes, they chose that particular rotor because the 4 lug pattern was the same as the pinion flange of the 2.5 ton rockwell. It literally bolts right up.

 

[welldigger]

Well after reading their description of the pinion brake my local shop offers I learned a few things.

1. You can run them in conjunction with a drive shaft.

2. They use a Toyota caliper and Mazda rotor. What models specifically I do not know.

3. The rotor does need minor modification.

 

[peashooter]

Aaron check out this site. At work we had these on our older 40ft busses. They can almost bring a fully loaded bus to a complete stop. They make them for all kinds of applications.
http://www.telmausa.com/products/operating-principle

Thanks Greg, I just shot them an email for some rough pricing. Maybe I'll call this Mico company also, they are 2 hours away from me and perhaps could offer some suggestions. https://www.mico.com