M35A2 brakes not working. Help.

[AyWoSch Motors]

Hello all.
I haven't been active here in a while, but I just recently bought a Kaiser M35A2 to add to the fleet.
Bought it at my local junkyard. Got it running there, with some junkyard parts, then drove home. Found out the brakes don't do anything, pedal just goes straight to the floor. I just downshifted and use low gear, and let the engine do the braking. Got it home safe and sound. But now I want to get the brakes working.
I'm unfamiliar with this truck in general, completely new to me.

Are they air brakes? Hydraulic brakes? Air assisted hydraulic brakes? I honestly don't now. From what ove heard they're air.
The air pump seems to be working, it built pressure after it ran for a while, and after I shut it off, I heard it release.

I'd like to know what I should be looking for, how to fix it, and what I'll potentially need for parts.

Thank you.

 

[Mullaney]

Hello all.
I haven't been active here in a while, but I just recently bought a Kaiser M35A2 to add to the fleet.
Bought it at my local junkyard. Got it running there, with some junkyard parts, then drove home. Found out the brakes don't do anything, pedal just goes straight to the floor. I just downshifted and use low gear, and let the engine do the braking. Got it home safe and sound. But now I want to get the brakes working.
I'm unfamiliar with this truck in general, completely new to me.

Are they air brakes? Hydraulic brakes? Air assisted hydraulic brakes? I honestly don't now. From what ove heard they're air.
The air pump seems to be working, it built pressure after it ran for a while, and after I shut it off, I heard it release.

I'd like to know what I should be looking for, how to fix it, and what I'll potentially need for parts.

Thank you.

.
The M35A2 has what are called a single circuit brakes. You loose braking on any of the six wheels (fluid pouring out of a wheel cylinder or a broken brake line) and you have no brakes. Definitely hydraulic brakes with Air Assist is a nice way to describe the system. On older A1 trucks, they can be vacuum powered brakes on those trucks.

Brake failure can be a "regular thing" if the truck has been sitting for a while. If there was fluid when you started driving, you should have a wet backing plate to show you what happened. Getting a new brake booster will be important to get started solving your brake problems. New wheel cylinders. Carefully inspecting the brake lines - both rubber and steel.

 

[m715mike]

As Mullaney said, it’s an air over hydraulic break system. I would recommend starting by bleeding your breaks. Make one of these:

Deuce Power Bleeder R4x4 Style

Gang, here are 2 pics of my bleeder. You can see that the tank line has a ball valve and a quick coupler from an air line. It then connects to a second hose that has a tee and a 6" nipple that screws into the MC cap. There's a plug in the top of the tee but eventually it will have a pressure...

www.steelsoldiers.com

You have a master cylinder, air pack, wheel cylinders and lots of hoses that should be carefully inspected and possibly replaced.

Here’s some other good information:

DEUCE BRAKE LINE REFERENCE GUIDE (Sizes, lengths, fittings)

POST 1~ SINGLE CIRCUIT BRAKE LINES POST 2~ DUAL CIRCUIT BRAKE LINES POST 3~ BRAKE PARTS REFERENCE GUIDE POST 32~ BRAIDED STAINLESS FLEX LINES/HOSES POST 40~ DUAL CIRCUIT MASTER CYLINDER BRACKET INFO & CAD FILE SINGLE CIRCUIT BRAKE LINE INFO I've been selling Stainless Steel Braided Flex hose...

www.steelsoldiers.com

 

[Mullaney]

As Mullaney said, it’s an air over hydraulic break system. I would recommend starting by bleeding your breaks. Make one of these:

Deuce Power Bleeder R4x4 Style

Gang, here are 2 pics of my bleeder. You can see that the tank line has a ball valve and a quick coupler from an air line. It then connects to a second hose that has a tee and a 6" nipple that screws into the MC cap. There's a plug in the top of the tee but eventually it will have a pressure...

www.steelsoldiers.com

You have a master cylinder, air pack, wheel cylinders and lots of hoses that should be carefully inspected and possibly replaced.

Here’s some other good information:

DEUCE BRAKE LINE REFERENCE GUIDE (Sizes, lengths, fittings)

POST 1~ SINGLE CIRCUIT BRAKE LINES POST 2~ DUAL CIRCUIT BRAKE LINES POST 3~ BRAKE PARTS REFERENCE GUIDE POST 32~ BRAIDED STAINLESS FLEX LINES/HOSES POST 40~ DUAL CIRCUIT MASTER CYLINDER BRACKET INFO & CAD FILE SINGLE CIRCUIT BRAKE LINE INFO I've been selling Stainless Steel Braided Flex hose...

www.steelsoldiers.com

.
Nicely done Mike!
Good information compiled and shared in one spot.

 

[Charlie175]

The one I got had been sitting for a few years and my pedal was dead. Checked the master and it had little fluid in it. Topped it off with DOT 5, opened the bleeder next to the air pack until fluid came out. Then bled all the other lines at the wheels. Brakes now work.

 

[AyWoSch Motors]

Thank you allie the tips.

Okay, so I checked the brake master, it still had a little fluid in it. I would say enough to keep it bled, I topped it off with some fresh anyway to be sure.
None of the drums or wheels are oily, all the lines are solid and dry, the master is dry, no leaks in the system that I can see. Still no brakes. Pedal seems to do absurdly nothing just goes to the floor like theres nothing behind it. I can view threw the trap door on the floor and see it going in and out of the master, but it feels like it's not even connected. Is it possible the seals are completely shot and it's not building pressure at all?
Also, I made sure there were no major air leaks or problems anywhere. The glad hands are shut off, the air pet cock is shit off, the system builds and holds pressure nicely when running, although after I shut it off, I can hear it leaking out of the cylindrical apparatus that resides (not familiar with what it is) under the brake master. Not sure if that would have anything to do with it.

I do need to buy or download a TM for it, but havent had the time yet. And although it may seem it with this, I'm not a rookie when it comes to working on cars, I'm very knowledgeable with all my trucks and jeeps, but this one is new to me.
If this were happening to my truck, id say the master cylinder is dead.
But before I go ripping it out of there, I wanted to go over all the easier options first. Is it possible that it still needs to be bled? Shouldn't it give me some sort of a pedal?

 

[Elk1111]

Did you bleed them?

 

[AyWoSch Motors]

Did you bleed them?

No, didnt feel necessary since the reservoir still had some fluid and the pedal doesn't feel like it would pump anything even if I did.
I can if necessary.

 

[Elk1111]

Definitely necessary.
Make a power bleeder as shown on the post above. Bleed the air pack first, then rear axle passenger side, rear axle driver side, middle axle passenger, middle axle driver side, front passenger and front driver last.
It holds a lot so just filling your master cylinder won’t do much.

 

[AyWoSch Motors]

Definitely necessary.
Make a power bleeder as shown on the post above. Bleed the air pack first, then rear axle passenger side, rear axle driver side, middle axle passenger, middle axle driver side, front passenger and front driver last.
It holds a lot so just filling your master cylinder won’t do much.

Oh okay, will try that.
I have bled brakes before, I'm familiar with doing the farthest away ones first.

Is it normal for the pedal to do absolutely nothing though even if in need of bleeding?

 

[Elk1111]

Yes.

 

[Charlie175]

Yes indeed bleed them. Air in the system will just compress and you will have no brakes.
It does sound like your brake air pack needs to be looked at. If that is froze up then you won't have brakes either. It takes air pressure to operate the brakes

 

[m715mike]

When I went to power bleed my breaks for the first time, my air pack was making the same noise you described. I put a little pressure in the power bleeder and all of a sudden I heard fluid hit the shop floor. The air pack sprung a leak and a steady stream of break fluid was pouring out. I replaced the air pack, bled the breaks and was good to go.

Note, I was bleeding the breaks to begin with because I had just replaced the master cylinder.

 

[m715mike]

I do need to buy or download a TM for it, but havent had the time yet.

All of the Deuce TMs are available for free on this site:

TM's for the Deuce

Listed below are a number of the TM's for the M35 trucks. To save them to your computer, right click, select "save as". GTA-9-1-1851-8.pdf M35 complete diagram of with descriptions of all components. LO9-2320-209-12-1.pdf LO9-2320-209-12-1 Lubrication Order for the M35 series...

www.steelsoldiers.com

 

[Mullaney]

No, didnt feel necessary since the reservoir still had some fluid and the pedal doesn't feel like it would pump anything even if I did.
I can if necessary.

.
Looks like the guys got you fixed up with where to download the (Free) TM's. There are flow charts on how to do things like bleeding brakes and replacing the powerpack / brake booster.

You could have crus and corrosion inside the master cylinder that has slowly stopped up the little pin holes in the MC where the fluid enters and exits the piston that moves back and forth. It could even be corroded in the "compressed" state and the little tiny wire spring could be rusted away to nothing. All worth looking at - if just straight up bleeding the brakes doesn't work.

A power bleeder that you can build yourself is here:

Deuce Power Bleeder R4x4 Style

Gang, here are 2 pics of my bleeder. You can see that the tank line has a ball valve and a quick coupler from an air line. It then connects to a second hose that has a tee and a 6" nipple that screws into the MC cap. There's a plug in the top of the tee but eventually it will have a pressure...

www.steelsoldiers.com