Pinion brakes

[topo]

I would like to see a better park brake on these trucks at least one that can be trusted to hold a loaded truck on a hill .

 

[50BMG]

I've never tested the brake on a loaded truck on a hill.However my truck will hold on a steep road when I have to open my gate,but it only weight about 11000 lbs.I do lock the difference and put it in 4x4.

 

[quickfarms]

I was taught to drive by floating gears and downshifting do an almost complete stop, twin stick Mack usually running about 60k on three axles. You are not driving a car, you are driving a big truck. When properly set up an Allison will downshift to a stop but the engine must be running.

 

[rustystud]

Though is was at five mph the truck should stop in 20 feet with just the emergency brake pulled and truck aired up. I would be willing to bet if I was pull just my parking brake on my 915 she will lock up at higher speeds just going to be a long stopping distance. Would hate to try it though. The S cam on my trailer will lock them up to if the trailer becomes disconnect. With air brakes the adjustment is the important thing. Even automatic slack adjusters can fail to adjust. As said I would forget the pinion brake. With the Deuce yes I would pull the engine shut down if a emergency came up. The best thing for a system like the Deuce or 809 series is to KNOW the slave cylinders are in good working order. From there then is a good working master and air pack.
Here are the guide lines for 20mph. The figures would then go up as the speed increase. I guess they figure if your air brake system can be within the guidelines for 20mph then it should stop at higher speeds just need more footage. The problem would be the DOT officer could not make use do a 70 mph emergency stop as things could go very wrong. So they just could have us do one at 5 mph. Never seen a Dot officer test the brakes that way they just measure the throw.https://www.law.cornell.edu/cfr/text/49/393.52

We performed those 20 MPH tests all the time on the buses. In fact it is mandatory before and after a brake job. You do the test three times, and it must fall within specs every time. The parking brake test is performed every 6,000 miles.

 

[doghead]

I posted to get peoples opinion on the subject, I got a lot of different ideas but nobody seems to know for sure.If you don't want discussion then don't reply!

Actually, had you searched before asking, before buying, you would have a full bank account still.

This topic has been discussed many time in great detail.

fwiw, the original parking brake IS a pinion brake.

 

[sandcobra164]

Opinions tend to be formed one or two ways. Some people have been around stuff and have a good idea as to how it's going to work out without actually trying it. We'll call this group A for this discussion. Some people have ideas of how they think something should work and form opinions based upon that. We'll call this group B. Some people have an idea that they've seen used in an application before and think they can improve upon it. They are normally mechanical engineers and we'll call this group C. Most people on here hang out in group A and so do I. I think you are in group B and do not like the responses from group A. Find some people in group C but you may wind up with the same responses. I've met uninformed people in my group and your group. I've never met a dumb credentialed mechanical engineer. It was pointed out earlier that they run pinion brakes on monster trucks that go slower and weigh less than your truck. They also stated that the rotors are glowing after a run which has a great potential for boiling the brake fluid. I'm not an engineer but that does not sound like an ideal situation for a braking system that would be applied going down the road. I do think it has merit as an idea to replace the factory parking brake system if you desired to do that.

 

[50BMG]

Sandcobra,you sound like a very intelligent person but you missed the point,I'm not replacing the E brake I'm adding 2 pinion brakes and leaving the stock brakes.It has nothing to do with monster trucks.I don't care how much it costs or how long they last ,it's just a toy.I'm sorry I posted on this forum because it ruffled the feathers of the gurus.I was trying to get imput and have a discussion, but apparently that is for a different forum!

 

[98G]

Sandcobra,you sound like a very intelligent person but you missed the point,I'm not replacing the E brake I'm adding 2 pinion brakes and leaving the stock brakes.It has nothing to do with monster trucks.I don't care how much it costs or how long they last ,it's just a toy.I'm sorry I posted on this forum because it ruffled the feathers of the gurus.I was trying to get imput and have a discussion, but apparently that is for a different forum!

I for one will be glad to see some real world info from them. Please post your results once you get them on and try them out, good bad or indifferent.

 

[doghead]

I'm curious what you ordered and what their advertising suggested.

Please tell us what you ordered.

 

[simp5782]

Sandcobra,you sound like a very intelligent person but you missed the point,I'm not replacing the E brake I'm adding 2 pinion brakes and leaving the stock brakes.It has nothing to do with monster trucks.I don't care how much it costs or how long they last ,it's just a toy.I'm sorry I posted on this forum because it ruffled the feathers of the gurus.I was trying to get imput and have a discussion, but apparently that is for a different forum!

Apparently you should have done your homework before buying the parts if you wanted advice. By asking for "how good will a pinion brake be?" After you already bought them means you have already made your mind up to install it. You should have upgraded your existing brake system if you were looking for better braking and safety over what "looks cool" when 1 in 5 people who will look at your truck will even have a clue as to what it is. Pinion brakes should only be used offroad applications or for a parking brake in my opinon. But in your case your decision to install a pinion brake may be your only savior.

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[patracy]

I've offered some facts. I would ask one thing though. If you plan on adding this to your vehicle, please have it ran on a separate hyd system.

 

[50BMG]

Thank you all for your input.I will be running 2 pinion brakes 4 drum brakes 1 emergency brake with a Rockwell locker in the rear and a ARB in the front,sometime this year I will put disk brakes on,but that looks like a lot of work.I am 70 years old and always done things against the grain,please don't take this personal but I'm going to try this and I will report the results.

 

[Jbulach]

Thank you all for your input.I will be running 2 pinion brakes 4 drum brakes 1 emergency brake with a Rockwell locker in the rear and a ARB in the front,sometime this year I will put disk brakes on,but that looks like a lot of work.I am 70 years old and always done things against the grain,please don't take this personal but I'm going to try this and I will report the results.

With all bashing, Its still not clear how your going to use these, are you plumbing them into your primary brakes, or are they going to be used as an emergency brake system only.

 

[50BMG]

For now I'm going to plumb it into the stock system,but a dual system sounds pretty good.

 

[porkysplace]

For now I'm going to plumb it into the stock system,but a dual system sounds pretty good.

So what are you going to use for a proportioning valve ?

 

[50BMG]

I don't know,I'll cross that bridge when I get to it.

 

[porkysplace]

I don't know,I'll cross that bridge when I get to it.

Well your at that bridge as soon as you hook into the stock system , they will lock as soon as you apply the brakes and you will never get enough fluid to the wheel cylinders to activate the wheel brakes without a proportioning valve matched to the spring tension on the wheel brakes . This is hydraulic braking 101.

 

[50BMG]

Dam,Porky place why didn't you tell me that before?

 

[Jbulach]

You should be able to find an adjustable valve that you can back the pinion brakes all the way off if necessary.
The next issue will be how much fluid volume all those pistons are going to require a master cylinder to push...

 

[patracy]

I don't know,I'll cross that bridge when I get to it.

Might I suggest searching brake failures here? It's unfortunately common with the single circuit system. Maybe it will convince you to at least use a dual circuit system. I'm guessing it won't, but I will sleep better tonight at least.

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