Another day another brake petal on the floor

[Goose2448]

Im thinking of using it for a parking brake, with the parking brake cable, not the hydraulic system.

 

[Heath_h49008]

Im thinking of using it for a parking brake, with the parking brake cable, not the hydraulic system.

Actually, you could do both.... Use a caliper from a Lincoln Versailles 9" rear, or any of the other old calipers that had a built in cable brake. Most of them are kinda dinky, but for just a parking brake, with a 6.72:1 advantage, it should be fine.

 

[CobraCDR]

Glad you, the truck and noone around you got hurt with this.

 

[mktopside]

I don't agree, It has been proven that pinion brakes are effective on these axles, also they can be mounted directly to the axle, there are several guys on pirate 4x4 that have proven this point, and are using them as SERVICE not emergency brakes. they may use them in offroad situations only but that doesn't mean they dont use them at near highway speeds on a daily basis.

3,000lb wrangler =/= 14,000 truck. It's not a fair comparison.

Ok, I'll play along though.

One massive rotor made out of a high quality stainless, one massive caliper, and the most expensive racing brake pads you can buy. Tank of CO2, with a small sprayer manifold aimed at various points on the rotor. It would be a limited use "oh ****" device. Rig it so that when you stomp on your secondary pedal, the CO2 tank fires onto the rotor.

I'm not even sure that is going to cool it enough, and I don't thin the drive line components will be able to handle it, though I guess you could mount it right on the front tandem pinion flange.

 

[bones1]

Take a look here M35A2 Dual Circuit Brake System Upgrade

 

[Heath_h49008]

3,000lb wrangler =/= 14,000 truck. It's not a fair comparison.

Ok, I'll play along though.

One massive rotor made out of a high quality stainless, one massive caliper, and the most expensive racing brake pads you can buy. Tank of CO2, with a small sprayer manifold aimed at various points on the rotor. It would be a limited use "oh ****" device. Rig it so that when you stomp on your secondary pedal, the CO2 tank fires onto the rotor.

I'm not even sure that is going to cool it enough, and I don't thin the drive line components will be able to handle it, though I guess you could mount it right on the front tandem pinion flange.

One massive one, two slightly less massive, etc... We have 8 locations to play with. It's just a question of complexity/cost/functionality.

If these offroad guys are stopping 3000lbs (conservatively) at 70+mph with one Mazda rotor and a single toyota caliper (so they say). It would seem we could achieve similar results with 23,000 lbs (truck+rated load) by having 7... and the Wilwood 12.5" rotors and GM truck calipers/pads are a whole lot more effective than the tempo/Toyota combo these guys are running. So we should be able to cut that number down quite a bit... Also, we aren't trying to use them as primaries. I'm hoping that 3-4 will do in the emergency capacity, given those two factors in our favor.

One on the front, two on the center axle, one on the rear... just in case they have lock-outs, also it would be the same MC/etc for "bobbers"... just two on each axle.

I know how to stagger the secondary system so the bulk of the load is on the factory drums... but I want to verify what these 4x4 guys are doing. So far I haven't found any grenades... most of them seem more worried about breaking u-joints.

 

[jtron79]

3,000lb wrangler =/= 14,000 truck. It's not a fair comparison.

Ok, I'll play along though.

One massive rotor made out of a high quality stainless, one massive caliper, and the most expensive racing brake pads you can buy. Tank of CO2, with a small sprayer manifold aimed at various points on the rotor. It would be a limited use "oh ****" device. Rig it so that when you stomp on your secondary pedal, the CO2 tank fires onto the rotor.

I'm not even sure that is going to cool it enough, and I don't thin the drive line components will be able to handle it, though I guess you could mount it right on the front tandem pinion flange.

I'm trying my hardest to not completely flame your engineering knowledge.

#1 the setup pictured is on a 1/2 ton dodge full size pickup, it's got a 440 big block and runs 11x20 tires, I doubt seriously he is running anywhere near 3k lbs, again the setup works like a dream as SERVICE brakes.

#2 go ahead and make any mechanism that will get hot and shoot co2 on it, then we can discuss dangerous exploding brakes.

#3 the only way the drivetrain would receive any stress from a pinion brake would be if the engine was still powering the truck during braking, braking action at the pinion would not transfer up the driveline or endanger any other component from there up.

 

[Outlaw86er]

Don't most monster trucks run pinion brakes? Monster trucks may not go as fast as these trucks but i'd imagine they have more gear reduction which means the brakes are probably spinning at least as fast and they seem to hold up ok. I also believe HMMWVs use inboard brakes and although not quite the same the gear reduction of the portal axles would mean they turn faster than the tire by some degree.

 

[Heath_h49008]

This actually looking more plausible from what I'm seeing these 4X4 guys do. Those trucks are way over 3000lbs... some I would guess a whole lot closer to 10k. And none of these guys are running more than 2 discs, as SERVICE brakes.

We can do this... we might need more discs, but I'm really starting to think it will work. 3-5 makes sense from a simple math standpoint, I have seen no grenaded rotors, or complaints of anything like it. I'm still looking for hard data to work the numbers.

 

[Mike O.]

My stock Gen1 Dodge CTD weighed in empty at 5900 pounds.

 

[swampzr2]

My rock buggy weighs in over 5,500# and runs 2 pinion brakes. I have driven it on the road up to 45 MPH and have not had problems with the brakes exploding from heat. No smoke in fact from them either. The problem with them is they are very sensitive, and it is real east to lock up the tires. But I think it is a great idea for emergency situations.

 

[Heath_h49008]

So, if they are touchy... which would make sense given the mechanical advantage they have on the wheels... splitting off 2 more calipers and running 4 discs might work to increase braking surface, as well as calm the rate down with the extra volume requirements. At worst, a few proportioning valves...

What rotor are you running?

4 GM calipers.. $20 each
2 sets pads ($20-$50/set)
4 rotors... (Variable...)
4 brackets (Anybody else have a plasma or laser table available?)
1 junk s10 master cylinder ($5 at the junkyard)
Fittings, bolts, and lines... (Oh My!)

 

[hemichallenger]

I thought that was the plus of the split system not loosing all your brakes?

I did also. Could not belive that this happened.

 

[x-ray]

I did also. Could not belive that this happened.

Ted - Any follow up as to the root cause? I'd like to know if you traced it down and what you learn from review. Lines ruptured/broke? Hydrovac? ??

Thanks and hope you get it going again.

 

[joshs1ofakindxj]

#3 the only way the drivetrain would receive any stress from a pinion brake would be if the engine was still powering the truck during braking, braking action at the pinion would not transfer up the driveline or endanger any other component from there up.

In addition, drive train stresses in the axle felt by pinion breaking would be comparable to those experienced during engine breaking and acceleration. Busted!

 

[hemichallenger]

Ted - Any follow up as to the root cause? I'd like to know if you traced it down and what you learn from review. Lines ruptured/broke? Hydrovac? ??

Thanks and hope you get it going again.

No I am not sure if it was caused by 1 air pack leaking or both. I pulled both feed lines and sprayed pb blaster in. I should have done I at a time but did not think of it at the time. I am pulling them both for inspection and rebuild.

 

[mktopside]

In addition, drive train stresses in the axle felt by pinion breaking would be comparable to those experienced during engine breaking and acceleration. Busted!

No it wouldn't. Unless the pinion brake takes the same amount of time to go from 60-0 as it takes the truck to go from 0-60. I've never driven a vehicle where the engine can slow it down as fast as regular brakes can, and certainly not as fast as a pinion brake will.

All BS aside, one of you proponents just needs to do it and see what happens. How they work on someones rock crawler that weights 5500lbs is irrelevant, as these trucks are almost 3 times the weight with a moderate load in the bed.

So, since it's so cheap, and since many of you say it will work perfectly, there's no reason one of you shouldn't have this fabbed up by the end of the weekend. For the purposes of testing, I would just mount the MC on a plate and activate it with a long handle. That way it's easy to remove if it doesn't work.

 

[Heath_h49008]

No it wouldn't. Unless the pinion brake takes the same amount of time to go from 60-0 as it takes the truck to go from 0-60. I've never driven a vehicle where the engine can slow it down as fast as regular brakes can, and certainly not as fast as a pinion brake will.

All BS aside, one of you proponents just needs to do it and see what happens. How they work on someones rock crawler that weights 5500lbs is irrelevant, as these trucks are almost 3 times the weight with a moderate load in the bed.

So, since it's so cheap, and since many of you say it will work perfectly, there's no reason one of you shouldn't have this fabbed up by the end of the weekend. For the purposes of testing, I would just mount the MC on a plate and activate it with a long handle. That way it's easy to remove if it doesn't work.

Sure... but I'm a poor college student... Give me until spring.

I'll build it with 4 GM calipers, the biggest cheap/common rotors I can find, and an unboosted S10 master cylinder.

We'll see what happens.

 

[m37dsl]

I think the pinion brakes would work well for an emergency backup on a 6x6. I run them on my crawler (8500 lbs) and if i remember right the kit from DIY4x4 was only 110$ per axle (all you need is a loaded caliper). As mentioned earlier in this thread they are touchy but i have stopped this truck with them at some pretty signifigant speeds (45ish) and some long hills with no smoking or discoloration of the rotors.

Would i trust pinion brakes on a daily driver, no.

Would they work in an emergency situation without all the doomsday scenarios discribed above, yes.

 

[itsbrokeagain]

im kinda curious to see how this plays out. Some great discussion going on here.

Ive seen monster trucks get these brakes glowing red hot, but they are also in the range of 50+ mph coming out of that first straight, hauling hard on the brakes. Slowing down a 10-15k lb monster truck takes some serious braking (ive seen them wear out on some trucks and just turn into a glowing pile of melted metal at the end of the run).

I think even with bigger rotors and a proper master/caliper setup, they wouldnt be so touchy to use even in normal everyday operations.