I searched for nearly 30 minutes and no info unless I want to upgrade to rear discs. At this point not interested, so here goes. I have 78 f250 ranger camper special 4x4. I have been trying to figure out why the brakes dont work. The fronts seem to be working fine, but there is nothing at the rear. Twice I have bled the brakes. Once with a helper doing the push and hold while I turn the bleeder screw. And again tonight using gravity. I ran close to an entire reservoir's worth of fluid out while being sure never to let it get below half full. I am sure I did not introduce air. Tonight I pulled the axle, and the hub/drum assembly to see if both shoes are working. They were. So I ruled out a locked up wheel cylinder. I did this only on one side, but at that point I was convinced something else is at fault.
With the vehicle on jack stands I have to push the brake down to the floor as hard as I can to keep the wheels from spinning just off idle.

Any ideas where I should look next? I have a 21 foot jet boat that I tow and I am looking forward to buying a camper. I need to fix this problem before I can safely do one or the other!

Any thoughts appreciated.

Todd

 

Proportioning valve bad, maybe.

 

Make sure the parking brake cable is not sticking and holding the shoe off at the top of the wheel cylinder. The shoes will show to be moving, but there is so much slack it is like the brakes are not adjusted properly. This gave me a fit for a while till I found the bad cables. Also are both sides of the wheel caliper pistons free? Bruce

 

maybe? How do I know?

Got to be a way to diagnose this problem step by step without throwing potentially unneeded parts at it.

But, keep 'em coming please!

 

If you still have the hub off it is easy, The park brake cable hooks to the arm, I take a big screwdriver and see if you can pry the arm toward the rear of the truck. The spring on the cable is supposed to pull this arm back to proper position. The arm should not pull the rear shoe out at the top. If you can push teh top part of the shoes in any at all, there is play that the small stroke of the wheel cylinder can't compensate for and apply the brakes. Bruce

 

If adjustment of shoes and e-brake cables are good then...
Possible master cyl... To isolate where the problem is, do a line lock test.... Put vice grips on both the front hoses, and one on the rear. Is pedal still on floor..? Then it's master. Is it high and hard..? problem is elsewhere. Remove one of the vice grips from the front, and test pedal. Put it back, do other side the same. Remove the rear one, noting pedal again. when the pedal went to floor with clamp removed, that will be where problem is. You might want to pull the other side apart to make sure it's ok too, wheel cyl not leaking etc.

Odds of a prop valve are very slim.


Hope this helps you some, I know D60's are a bugger to pull apart...

 

If you are not sure about the cable. Take the cable off at the arm on the rear shoe and put back together and adjust brake and try. Bruce

 

Any resistance to the brake pedal when it dives to the floor?

Replaced the master cylinder or the booster recently? The booster push rod may be not reaching its full travel needed to push fluid onto all four corners.

How does the brake fluid look in the master cylinder?

 

Can forcibly clamping my soft hoses cause permanent damage?

I am not sure I follow the Ebrake cable and the adjustments Moose is talking about, but I will read this again and try to make sense of it in the daylight.

All the fluid is new. I blew out a steel line in the brakes about 3 months ago. Mud and grime had packed in the frame rail against the side gas tank and rotted the line from the outside in. This brake problem was going on then too. I was towing the boat and didnt see a stop sign as soon as I should of. I braked hard to stop and pedal went clear to the floor.

As is now the pedal does not dive to the floor, it does not even go down that far. It just takes almost everything I have in my leg to hold the rear tires from spinning under very very light throttle.

 

If the hoses are old, there is no tellin' what they will do.

Remove the master cylinder cap and push down the pedal. If fluid shoots up, you have air...get to bleeding.

Sounds like the rear brakes need adjusting or they are far too gone to be adjusted - worn down shoes and/or drums.

Take the drums off, adjust the star wheel until the drums are slightly touching the shoes. Then back up and stomp on the pedal several times. Lastly drive forward for a bit. See if it improves any.

 

Yes there is resistance when the pedal is at the floor, just no brakes at the back.

Have not replaced any brake components except for front calipers. They were dragging when I bought the truck. That is why I pulled the hub to see if the wheel cyls were possibly not working at each end of the cylinder. Pulled one side and when brakes lightly applied without truck running both arms on the wheel cyls pushed outward!

 

Then the rears need adjusting. Do what I said above and report back.

 

The shoes on the side I pulled down were Okay. No excessive wear. The drums have at one time(the 1 I looked at) had gone too long without shoes as there are grooves in the drum from rivits. I know this will decrease my braking surface, but this is definately not my problem.

After thinking about the hose deal, there is a good possibility that theat the rear hose is ballooning and not getting the pressure to the wheel cyls.

 

In that case - Replace the bad drum.

Stop speculating. Just diagnose, already.

 

I bled like crazy tonight, but will pull the cap off and do as above, I did adjust both brakes tonight and there was no change.

Any way to tell if the rear hose is bad with out possibly damaging clamps?