E Brake not Working After Rebuild

[adis]

The brakes were bad and getting worse on my '80 K30 dually. Rear drum brakes were old, rusty, and had been leaking either cylinder or axle seal.

I rebuilt the rear hub/drum assy (brakes, bearings, seals, drum turned to ~13.07). This stiffened up the brakes significantly, and the brake warning light from the combo valve went off (except for slamming on brakes from 30+ mph - light comes on then immediately goes off) - but my ebrake does not hold the truck on a hill.

i adjusted the cable/pedal - it is tight at 1/2 way. when the ebrake is engaged, with trans in N i cannot spin the DR side by hand, but can on PASS side. When i rebuilt brakes I cleaned up the ebrake levers and greased the pin that holds them to the shoes (they move freely), cleaned up link and replaced spring on the ebrake link between the shoes. Adjusted the shoes by fully assembling hub/drum/wheel, then extending starwheel as far as i could to seat shoes, then backing off until wheels just spin freely.

Any suggestion as to how to troubleshoot this? Frankly, I cannot be sure that the back brakes are functioning other than when I adjusted the shoes fully tight - they held the wheels. So I presume my rebuild was correct. The ebrake pedal and cable are tight to the point where I can't get them past about 5/8.

BTW, truck weight ~7000. Perhaps the ebrake just doesn't hold that? The truck is new to me so I don't know if the ebrake ever worked, but it seems like it ought to hold the weight of the vehicle + load (or I want it to anyway.) Thanks for any suggestions as to where to start looking. - mark

[franken]

Just a guess but typically, there are 2 ebrake cables; one from the pedal, and one that loops between drumes. You said one side is better than the other. It sounds like the curved slider is binding.
Or, maybe the later (mine's a 72) uses 3 cables, but the concept is the same. Something where the front cable meets the rears.

[adis]

THanks for the suggestion, Franken. I went out and checked the cables. it's a standard "Y" ebrake set up. "primary" cable from the pedal to the turnbuckle, second "intermediate" cable with each end going back to its respective rear wheel, third set of "rear" cables, one on each side, inside sleeves that run into each drum and engage the ebrake levers.

when i engage the pedal, both sides of the "intermediate" cable going L/R are taught all the way back to where they join with the rear sleeved portion of the "rear" cable at each drum - so, I don't think the problem is upstream of that point.

with the pedal released and the cable slack, i put a piece of tape on each rear cable where it enters the sleeve, then engaged the pedal to see how far the cable moved when it tightened: DR side about 3/8" PASS couldn't see any movement. this leads me to think that there is binding either in the PASS sleeve, or in the drum.

i disengaged the "intermediate" cable and grabbed each rear sleeved cable with a vise grip pliers and pulled on each one to see if i could feel the cable moving the ebrake lever inside the drum. picture me laying on the ground head twd front, feet braced on the dually wheels, and pulling with as much strength as i could muster. i felt the DR side move, again maybe 1/4" to 3/8" - PASS side...nothing.

i really don't want to disassemble the drum again, but i'm afraid either the cable is bound in the sleeve (maybe where the sleeve housing bolts to the backing plate?) or some part of the ebrake mechanism itself (actuating lever or shoe link?) is out of place and bound up. is it possible for the cable to get rusted in place? the cable is not rusted outside the sleeve, it's actually in good serviceable condition. what a bummer

[Clyde65]

I have seen the cables rusted locked. Pull the PS drim and inspect, probably have to replace that cable.

[toolboxchev]

Sounds like you brake adjusters are way too loose or they are not working at all. Try driving backwards and slam on the brakes about 20 times. If your adjusters are working the brakes will tighten up significantly.

[adis]

Thanks for the replies, guys. looks like it was the rear cable. i disassembled the PASS drum and pulled the rear cable out. it was bound up from a combination of rust in the housing where it bolts to the backing plate, "waves" bent into the cable inside the drum, and a sharp bend in the sleeve where it exits from the backing plate. I worked it over, back and forth, with copious WD-40 and got it moving again, event to the point where the spring on the portion inside the drum would pull the cable back some when it was released. I reinstalled, and voila, parking brake holds. To be fair - I found out i was also kind of being a wuss when applying the pedal...

I'm not comfortable with the way the ebrake is at this point, but at least I know what the problem is, and that my brake rebuild was correct. I will replace the rear sleeved cable on both sides just to be safe (they're like $16 each at rock auto.) Thanks again for your suggestions - mark