Brake Problems on my M35A2

[SHOPPY]

I have a 1972 M35A2 that I am having brake problems with. The driver's side works very good when I shove hard on the brakes it will lay black marks on the driver's side. However, the passenger's side will not do the same even when I apply the brakes in gravel. The driver's side will slide, but the passenger's side will not. I have broken down the passenger's side rear brakes and have pulled the drums half way out and applied brake pressure and the wheel cylinders do work. I have bled the brakes and the driver's side works very well, but the passenger's side does not even come close to the same braking ability as the driver's side. I have even cleaned the brake shoes and drums very well with brake cleaner. I have adjusted the brake shoes at .010 at the bottom and .020 on top. Any assistance would be highly appreciated! Thank you in advance,
Steve

 

[jeffhuey1n]

Sounds like maybe your brake lines on the passenger side have some kind of contamination. The master cylinder could have contamination in it as well. It doesn't sound like the booster is involved unless it's picked up contamination from the other components. First, pull the passenger side front wheel and check it out. If it's okay, you'll need someone to help you. You need to check the flow of fluid through each wheel cylinder. That should highlight where the problem is coming from. Question: what type of brake fluid are you using?

 

[NDT]

I would inpect the rt side wheel cylinders for internal corrosion. Also, when bleeding, verify that the stream from the bleeder seems to be the same pressure all around, to eliminate the possibility of line restrictions.

 

[4x4 Forever]

Could possibly be the inside of the brake line is failing and not allowing the full pressure to build on the passenger side.

 

[SHOPPY]

I had my friend open brake bleeder all the way and put a hose on bleeder to a jar and then I stomped on brake pedal and it blue hose off bleeder on both rear axel pass side so I think the line is open.. I,m going to take it apart again and put new brake cyls on and flush lines again ,, Maybe the brake cyls are not working 100%,, I have flushed 1 1/2 gal of dot4 through the system.. # 5 cost about $100 a gal so I thought I would change to dot4. I have a good pedal and 2in free travel and brakes work good drivers side, not sure about steering brakes.. I took the brake air assist apart an it looked good inside so I put it back on , Thanks guys for the info I,ll let you know how it goes when I get to it thanks steve

 

[gimpyrobb]

Just cause fluid flows, doesn't mean it flows freely. How old are the rubber brake lines? I agree contamination would lead to this issue too.

 

[rustystud]

I had my friend open brake bleeder all the way and put a hose on bleeder to a jar and then I stomped on brake pedal and it blue hose off bleeder on both rear axel pass side so I think the line is open.. I,m going to take it apart again and put new brake cyls on and flush lines again ,, Maybe the brake cyls are not working 100%,, I have flushed 1 1/2 gal of dot4 through the system.. # 5 cost about $100 a gal so I thought I would change to dot4. I have a good pedal and 2in free travel and brakes work good drivers side, not sure about steering brakes.. I took the brake air assist apart an it looked good inside so I put it back on , Thanks guys for the info I,ll let you know how it goes when I get to it thanks steve

When you went to the DOT 4 brake fluid, did you totally purge out all the DOT 5 fluid with brake clean and air ? If you didn't you could have some contamination and the brake booster could be acting up because of it. Did you totally teardown the brake booster ? Or did you just take off the back housing with the boost piston in it ?

 

[SHOPPY]

Hey guys sorry about not getting back sooner.. I,m the guy that had no brakes on passengers side tandem.. Brake booster I took it all apart piston out and cleaned it good. There was no rust and very little contamination.. I took passenger side brakes off and they were soaked with brake fluid.. I cleaned brake shoes with laqure thinner but still socked with brake fluid.. I bought new shoes and new brake cylinders and now I have brakes.. I ordered new rubber brake lines for back tandem and will put them on next week.. I think most of my problem was brake fluid soaked brake shoes,,. When I changed to dot 4 I just bleed 1 gal of dot 4 through brake system and waited for my friend to say ,, it looks clear now . anyway that's the way I did it.. for now it works maybe later I will have problems.. I want to thank you guys for replying .. Hoppy ps Those brake shoes are a pain in the butt to replace,, worsed brake job I ever had to do.. 18 wheeler much easer to do