M35A2 brake upgrades

[nicholasktu]

I just got a bone stock m35a2, great shape except for leaky wheel cylinders. I have to some NOS that came with the truck and all new brake shoes, but would it be worth changing the front brakes to discs while keeping rear brakes original? Or better to just go discs all around?

 

[Mullaney]

I just got a bone stock m35a2, great shape except for leaky wheel cylinders. I have to some NOS that came with the truck and all new brake shoes, but would it be worth changing the front brakes to discs while keeping rear brakes original? Or better to just go discs all around?

.
Pull out your wallet and see how much money you've got.
If you have enough, go for it.

Otherwise, maintain what you have.

 

[nicholasktu]

.
Pull out your wallet and see how much money you've got.
If you have enough, go for it.

Otherwise, maintain what you have.

If I can find good reliable new manufacture wheel cylinders I might do that, it has a new master cylinder and booster on it (single channel).

 

[nicholasktu]

Are new wheel cylinders reliable? Or do they often start leaking like old ones?

 

[Barrman]

The problem isn’t the wheel cylinder bores. The problem is the cups that hold the fluid back. When they get old, they get brittle and don’t seal any more. All you really need is a new set up cups, a drill with a hone and a place to work on them. Here is a rebuild video:

 

[nicholasktu]

Looks like I'll be keeping the drums, most disc brake kits aren't made to fit the stock wheels. The brackets used in Hank's Deuce project are no longer available, that fab company isn't doing truck parts anymore. With new wheel cylinders, master cylinder and booster I should be fine for normal driving.

 

[nicholasktu]

Only option for front disc brakes is the Boyce kit. I tried getting drawings from Black Rock Fab but they don't have any drawings either. There is a 15" conversion kit but it doesn't fit stock wheels.

 

[El1T3 x M4R1NE]

Only option for front disc brakes is the Boyce kit. I tried getting drawings from Black Rock Fab but they don't have any drawings either. There is a 15" conversion kit but it doesn't fit stock wheels.

Where is this 15 inch kit you speak of?? I've got 22.5-inch rims and should be able to fit those rotors...

 

[nicholasktu]

Its Gearhart Engineering, he is still making the 15" kit. Its expensive though, and he's not selling many anymore. I want to design my own kit because the fab shops others used won't make them and got rid of the drawings.

 

[El1T3 x M4R1NE]

Its Gearhart Engineering, he is still making the 15" kit. Its expensive though, and he's not selling many anymore. I want to design my own kit because the fab shops others used won't make them and got rid of the drawings.

I actually just emailed him over the weekend, and yea he hasn't made any in over a year and isn't planning to for the foreseeable future. Sourcing parts like the rotors, calipers and hose is no biggy. I'm really just trying to get something with some decent brackets already made or even drawings and I'll make them myself, but I need a starting point. I would do the Boyce kit, but I'd really like a bit more stopping power that the 15 inch rotors would give...Let me know if you ever figure some good brackets, I will gladly buy them from you in a heartbeat and piece my own brakes together.

 

[nicholasktu]

I know Black Rock Fab and a member here (steve6x6x6) have made the brackets but both either disposed of the drawings or won't sell for liability reasons. I can design them since mechanical design is what I do for a living but its frustrating that its been done before but treated like a great secret.

 

[El1T3 x M4R1NE]

I know Black Rock Fab and a member here (steve6x6x6) have made the brackets but both either disposed of the drawings or won't sell for liability reasons. I can design them since mechanical design is what I do for a living but its frustrating that its been done before but treated like a great secret.

Exactly. Even though its equipment that's been around long enough that all kinds of things have been done, you'd never know with how difficult its been to find simple drawings. Anyways, I really like the brackets that black rock fab made for Hanks Deuce (pictures on hanks deuce website). It uses the f-550 calipers and 1994 f-600 15-inch rotors that I'm looking to use. I literally just need the brackets!!

 

[tobyS]

You know the wheel cylinders can be changed from 1 3/8 to 1 1/2" dia don't you? They did that on the A3 fronts and left the 1 3/8 on rears. I'm not sure volume is sufficient to use 1 1/2" on all 6 on an A2, but could as only small mod to push rod is required. It makes a great mod for A3 4x4 since they are 50-50 split and bigger tires have more torque on brakes.

 

[El1T3 x M4R1NE]

You know the wheel cylinders can be changed from 1 3/8 to 1 1/2" dia don't you? They did that on the A3 fronts and left the 1 3/8 on rears. I'm not sure volume is sufficient to use 1 1/2" on all 6 on an A2, but could as only small mod to push rod is required. It makes a great mod for A3 4x4 since they are 50-50 split and bigger tires have more torque on brakes.

I've already gone with the Boyce disc kit on my front brakes. Don't really want to deal with drum brakes at all really. I don't mind doing these mods gradually as they are $$$$. But eventually would like all 3 axles with disc brakes.

 

[nicholasktu]

I've already gone with the Boyce disc kit on my front brakes. Don't really want to deal with drum brakes at all really. I don't mind doing these mods gradually as they are $$$$. But eventually would like all 3 axles with disc brakes.

Are you happy with the Boyce kit? I though it looked a little undersized for the size of the truck.

 

[El1T3 x M4R1NE]

Are you happy with the Boyce kit? I though it looked a little undersized for the size of the truck.

The truck isn’t on the road yet, so I haven’t tried them out. But talking on the phone with the guy who runs Boyce, he says the same thing, that it seems his brakes could use some beefing up, but they just haven’t found a solid method to market yet. However, he says he’s had several happy customers who used the kit on bobbers come back and buy for a 6x6. He told them that’s not exactly what they’re designed for but they say it definitely works.

Im planning on also having an exhaust brake in my truck, gives me a little piece of mind hopefully when on downgrades.

 

[nicholasktu]

I still want to do the 15" kit like Hank did but I'll need time for designing the brackets. If I can find a scrap front axle that would help a lot for getting it mocked up.

 

[nicholasktu]

But I might just put all new wheel cylinders on with new pads and call it good. I won't use the truck for much hauling or highway use, just around the farm. And its not going to get many miles. The only thing I definitely want to do is power steering and air lockers for at least the rear axles

 

[El1T3 x M4R1NE]

But I might just put all new wheel cylinders on with new pads and call it good. I won't use the truck for much hauling or highway use, just around the farm. And its not going to get many miles. The only thing I definitely want to do is power steering and air lockers for at least the rear axles

But I might just put all new wheel cylinders on with new pads and call it good. I won't use the truck for much hauling or highway use, just around the farm. And its not going to get many miles. The only thing I definitely want to do is power steering and air lockers for at least the rear axles

If you mocked up the brackets on the front axle, would you still be able to use them on the rear axles? Because I’m keeping the rears dually…

And yes, air pockets would be nice, I’m going to be using my rig a bit more so that’s why I’m putting more mods on.

 

[nicholasktu]

They wouldn't work on the rear axles, no steering knuckle. But the rear axles aren't the problem, plenty of options out there for the fixed Rockwell axles, and its easy to make those brackets. The air lockers aren't necessary but I don't want open difs. I'd prefer to put something like Tru-tracs in the difs but they don't exist for the rockwells.