External contracting emerg brake? Help, Can't stop!!!!!

[uglytruk]

My '77 GMC 6500 dump has an ext,. contracting emerg brake just after the Clark 5 speed. It barely holds. Looks like lots' meat on the band, lever has lotsa' tension. Could the "drum" be glazed? How do I de-glaze? One of the center support bearings has a bad rubber ring. Do I have to replace the whole brg assy? Lastly, the fuel filter, mounted under the cab, (gas), is rusty. It looks like a small oil filter. About 2ish inches dia., unscrews from the mtg boss. Holley used to sell a chrome hi-po version that looked the same. Can't find it in the Holley/Colt ind. catalog. Should NAPA carry this housing? Do I have to replace the whole shebang?

[Steve Frazier]

I'd have someone verify that the band is actually actuating when you pull the lever. It may be bound or rusted somewhere along the line preventing the band to get tight, but making the lever feel like it's tight.

If this is the case you'll have to trace out the cable and either lube or replace it to get it to work freely.

The carrier bearings are usually complete assemblies that you replace as a unit.

I can't help with the filter.

[uglytruk]

I'd have someone verify that the band is actually actuating when you pull the lever. It may be bound or rusted somewhere along the line preventing the band to get tight, but making the lever feel like it's tight.


Thanks Steve, In fact the brake does hold, but I'd guesstimate about 33%. Sorta' like you could drive off and wonder what's wrong..... oops, :slomo emerg brake on!

[will_gurt]

Brake drum is more than likely glazed over. Filter... NAPA should have the parts you are looking for. If not try the local dealer they may be available still.

[uglytruk]

Took it apart last night, Drum is nothing special, a little grooved. Shoe worn to rivets. Axle pinion nut a little loose(?), dripping oil. What size socket? I only had 36mm.
What holds carrier bearing on splined driveshaft? Friction? Kinda' soft to hammer on.
Howcome shaft is same diameter as a car? My 3/4 ton '79 Chev is double dia.
Off to NAPA and any other truck shop :notworthy