Brake Question

[RBBailey]

So, my brakes are OK, if I double pump I get a lot of pressure, but who wants to do that?

So I start looking around for something to adjust. I get no further than the rear driver's side wheel and I notice that it has quite a bit of brake induced friction -- won't turn freely.

When I take the wheel off, it is the same. So, I pop the drum off, without much trouble at all. Brake shoes look good, but the front shoe is hardly touched, the rear shoe looks used, but just barely. It also has a 1/4 inch shaved off the top edge, like that's the only part really touching, or, like that is the part the is causing the friction when the drum is on.

So when I go push the cylinder back to get the drum on, the rear moves as you would expect, but the front piston is frozen. After much debate with various tools, I get the front piston in, but it won't come back out freely when the pedal is pushed. (It seems to have been frozen at a spot where the shoe wasn't touching, so it wasn't going in or out.)

When I get the drum on, the wheel and hub spin as they should -- until I hit the brakes, then it goes back to it's old ways of having too much friction.

One thing does not seem to be adding up to the other. The frozen piston would not cause the friction since that is not moving anyway, and it wasn't the shoe that showed rubbing on the corner. Secondly, figuring that the cylinder was bad, I got a new one (Lucas TRW). But the same piston (front) on the new cylinder does not move in or out in the same way the one on the truck does -- is it normal that it only has a very short, stiff amount of movement?

Could it be that the brake shoes are simply installed wrong?

Thanks,

 

[RBBailey]

Photos of the brake as is and the new cylinder.

 

[Le shed]

Have you checked that the return springs holding the brake pads in are in the right hole? There is a right and a wrong way to fit them. There are plenty of references of this on the web and in the green bible. It could be that the spring is too tight and the piston can't push it out. It is also possible that the pads are backwards/upside down and aren't parallel to the drum. Easy way to check is look at the other side, if that one is not doing the same thing. I can check on a new one I just took off here if you need. My axle is a Salisbury 109 type.
Good luck
Bill B

 

[RBBailey]

OK, got it.

New cylinder in means the braking was better, actually made a difference just to have that one piston working correctly. There was more actual feeling in the pedal, and more grab... but still not right. It still asks for a double pump to get good power to the brakes, but then you really have no feeling in the pedal at all. Just very stiff.

So I bleed the whole system, new fluid all through it. Much better, brakes feel like they should, but still get a soft pedal on the first try, way to stiff on the second pump. But the second pump still gave better power to the brakes.

Then I remembered the adjustments! So the shoes were adjusted too light -- there was just enough of a tiny space between the shoes and the drums to allow for some slack to be needed to be taken up on the first pump of the pedal. The bleeding of the system did take most of that away, but it was still there.

Now that I got it all worked out, I have original Series single line brakes that actually have some play in the pedal, cause the nose to dip when you brake hard, don't require double pumping, and I even locked them up once at 30 mph on a damp spot on the road in the shade!