This is turning into the devil-truck....

'90 F-350 dually, 3.5" brakes, RWD, RABS, 460.

Before - had fluid in RR drum, ABS/Brake light on solid. Fluid turned out to be diff. fluid, bad hub/axle seal.

Replaced seals on both sides, replaced shoes and hardware on both sides. All bearings were in great shape so they were re-used and reset with the proper # of clicks (8).

Cleaned diff cover, re-filled, checked everything else, and cleaned the ABS sensor.


On the test drive, brakes are super soft and I am not getting almost any solid brake feel. Did the auto-reset for the rear drums with 8 reverse/brake maneuvers. Towards the last few it felt finally like it grabbed solid....going in reverse only. When i put it back in drive the limp brakes return. So I re-did 10 reverse/brakes, same thing. After 6-7 it feels like it tightens up good, but when I go forward I have the soft pedal.

I thought I might have air in the lines - bled all 4 corners (no air at all), and re-test drove it, and now it's worse. It feels like I'm trying to slow the truck down with Honda Civic brakes...pumping the brakes doesn't do anything. And to top it all off, the ABS/Brake light came on again solid.

The truck doesn't pull left or right, it's just not stopping. When I got out, I felt all 4 corners and it's using all 4 brakes (warm to about the same degree).


Could the auto-adjust procedure not be working? Even if it isn't, why would the front brakes not stop the truck? I'll manually adjust them tomorrow in daylight. If the adjustment is not working, could that be the cause of the ABS light coming on?

Is there a procedure on how to bypass the RABS? I'm not sure where to put the hose that's supposed to bypass it. I can pull the dash light/fuse no problem.

Finally, can the adjustment screw be installed 'backwards'? I doublechecked the book (Haynes) and a few online photos, they have the threaded part of it going toward the front of the truck (on the right side). Basically with the 'stopper' tab, it should allow it to expand but not contract...it's a reach, but I'm starting to run out of ideas.

 

When I did the rears on my F250, I figured the auto-adjust would take care of them. It did not. That first day that I drove to work was scary to say the least. After I made it home that evening with some pretty hot front brakes, I tightened up the star adjusters on the rears until I had very slight dragging, then did the forward/reverse adjustment and they've been great since.

Jason

 

and make sure you have the short shoe towards the front of the truck

 

Dan,
As long as you didn't happen to mistakenly get any grease on the shoes or drums you should be sure to tightened up the rear star adjusters until at least there's some slight drag when you spin the wheels freely. Take it for a ride and see how it is. Then go ahead and do the self adjusting forward/reverse braking adjustment and they should be ok. Good luck!

 

you need to manually adjust them some when you put them on.

 

Yep - whoever told you to use the auto-adjusters never did brakes before. You absolutely must manually adjust them before they will work right.

 

just like when you do discs you need to pump the brakes to get the pads in contact with the rotors.

did not do this once and found out my adreneline pump worked just fine.

 

LOL... me too. I just did brakes on the car a couple weekends ago and spaced out on this step. Of course it's a 5 speed, so I didn't bother to use the brakes when I started it. I backed it out of the garage and of course the driveway runs downhill to the street. Of course when I hit the brakes they went right to the floor. And of course there was a car coming while I was rolling out to the street. Man, I never pumped brakes so hard in my life before then.

I got it stopped in time though.

 

wasn't that a good check of how high your blood pressure can really go without blowing a vein out?

 

I agree that you must adjust the new shoes up manually. Adjust untill the shoes are dragging when you turn the drums by hand. However I feel you still have some air in the system. Did you bleed the RABS valve unit on the left frame rail? If not bleed it and then bleed the rear brakes again.

 

Haha, yeah, those are fun times. Lost the brakes a few times myself, twice in my shifter kart and once in a Probe GT on hot lapping day...definitely sphincter testers, to be sure.


On the truck, manually adjusted the brakes and it improved a ton. Now they brake like they did when I bought it. We'll see how she holds up over the next few days.

Thanks to all who provided help and comments :tup: - and this forum's helped me considerably as well.