Need help - Drum removal

[TrojanPower]

I have spent all day trying to get his thing off. The truck is a 1972 C20 - 8 lug. I have removed the axle and spanner nuts/washers. The drum will turn by hand easily. Emergency brake is off. I have tried beating on it with hammer, PB blaster, and pullin on it like an idiot. I can slide the drum off about 1/4", after which it will not turn. Push it back flush and it turns. It has a very firm end feel after I slide it 1/4".

Looking at the back there are 2 open slots. When I stick a screwdriver in it just lifts/shifts the drum a little. Is there another opening I am missing? Some other bolt to loosen? I have read about turning down the adjuster but not sure how to do that.

Any ideas would be appreciated before I start drinking PB Buster

[100%Chevy]

It probably has a groove worn in the drum.You're going to have to make some slack in the adjustment wheel.
Mike.

[TrojanPower]

Any idea how to do that. I have looked for the break away opening at the 6pm position. Now I am wondering what the location of the adjuster star wheel is. It seems like on of the 2 open slots would be the answer, but here is not much room to work through those. Maybe a special tool is needed. I had read screw driver would do it, but hose are not at the 6 oclock position.

[Mryan]

You have to stick your screwdriver through the slot and turn the star wheel on the adjuster

[Stocker]

The adjuster is at the bottom (6 o'clock) position. Unfortunately some backing plates don't have a slot to access it. Makes it terribly difficult to remove the drums. I don't know the secret either.... When you finally get the drums off and can see the adjuster, drill a hole in the backing plate for future access. Then pop a rubber plug into the hole.

[my56chevytruck]

Would a wheel puller help? That's not the normal size wheel I've ever worked on but have had a similar problem with a 5 bolt wheel set up, but thats another story. Good luck

[panhead59]

x2-3. Yep you've got to loosen the adjuster at 6 o'clock position. After that all u can do is pry pull whatever to get em off. Then get groove machined off drum and make a slot ( if not already there) as suggested for future adjustment to "star" wheel. That's about all u can do as far as I know. There is a special tool with an angle on it to help with turning the adjuster. But it's just a flat screwdriver type tool with a bend in it. Just get the hole in drum at 6 o'clock position and try to stick a straight screwdriver in it to hit/turn adjuster. Just pry one way up or down till u find it is loosening adjuster and not tightening it. Some adjusters are rusted and will not turn. Back to prying, cussing/praying is about all u can do.

[Stocker]

Originally Posted by panhead59

Just get the hole in drum at 6 o'clock position and try to stick a straight screwdriver in it to hit/turn adjuster.

That could be a problem..... not all drums have access holes or slots in them. Mine don't.

[CCCC]

All of mine have openings to the adjuster (thank goodness) and only once encountered this situation - another fellow's truck - he had just about given up . I was able to get his drum off with a lot of effort and patience - put some serious pull strain on the hub while simultaneously turning it (backward, I think) with a bar across the studs. Protected the threads with padding and it took a while. It helped to have two persons.

Hope this helps you.

[Hutch]

My brother showed me a trick to break drums loose
Jack up the rear
Mount the tire and rim loosely
Start engine put in reverse accelerate the slam the brakes
Something like that

He has a one ton dually you might google that for a better description
I know it broke the drums loose quick and easy no beating

[100%Chevy]

This is about what it looks like inside the drum area.The adjuster is at the bottom about 6:30 or so actually and forward of the axle center.This pic is of the right side of the truck.
The adjuster on the left side will be at about 5:30 and on the rear side of the axle center.
Both are right hand thread.
These pics are from my 82,C-30.



This pic shows the ridge left when the shoes wear into the drum.The shadow under the piece of metal shows the gap.



Mike.

[TrojanPower]

thanks for the great advice everyone! Still working and no luck yet. Cut the spring pins, drilled out the access hole in front of drum but still cannot find the adjustment spring. Seem like drum comes off about 2" then just gets totally stuck. Must the be the shoes or just sticking on the axle/grooves. Feels like the bearings get stuck on the axle threads and everything locks ups.

[un4gvn!]

Can you see the flat part of the brake shoe retainer pins on the back of the backing plate? They hold the shoes to the backing plate. Take a grinder to them from behind the backing plate and the brakes will literally fall apart inside the drum. Grab the drum and wiggle it as you pull on it. You should replace them any how any time you do your brakes.

[Ironangel]

Were you able to collapse the slack adjuster? There's usually a thin plate at the top of the adjuster star wheel that is part of the auto-adjust mechanism. You have to push that thin plate off the star wheel to be able turn it. As long as that plate rests against the star the star wheel will only turn one direction and that direction will expand and not collapse the brake shoes. If your dealing with an unmolested brake assembly, you will be able to turn the star up and not down. The manuals indicate that you must push in on the plate with a screw driver while using the brake adjuster tool to turn the star wheel down to collapse the brake shoes. With all of that said, often over time brake dust and crud has gathered and stacked up on the exposed threads of the adjuster making it difficult if not impossible to turn the star wheel. That's where a can of brake clean comes in real handy to blast the threads on the adjuster clean before you foul the star adjuster threads into the collet. Might consider buying one of these... https://www.classicparts.com/1972-Sh...ctinfo/04-030/ If you use UN4GVN's method make sure you only work one side at a time, otherwise your going to be asking for pics on how to reassemble the mess. If the 3/4 ton C/20 brake shoes are like the 1/2 ton versions, pay close attention to the locations of the brake shoes. One shoe has a smaller lining than the other and will locate either fore or aft the axle housing. Here's a thread with some pics and lots of good info, the third pic down the thread a bit shows that pesky plate that holds the star adjuster wheel from turning backwards. http://67-72chevytrucks.com/vboard/s...d.php?t=443837

[paulspickupparts]

If your slack adjuster is turning you have an advantage . Many times they are froze. You may be going the wrong way and only making problems worse. When I remove rare and hard to fiind drums I often run across the same problem and only recommend this as a last resort. I take my cutting torch and point it thru the adjuster hole. When the adjuster is red hot I hit the oxygen and cut the adjuster. This frees up the shoes as they move inward about an 1/8 of an inch. I do no recommend this unless a last resort. I am doing it for salvage , you are doing it to rebuild Spray you adjuster with penetrant and back it off as far as you can. Take a flashlight and shine thru the adjuster hole and look at the pitch of the threads. Then it easy to see which way to loosen. You are ttrying to loosen so you see less threads on the adjuster. Probably a lip insed your drum causing all the grief. Good luck

[KQQL IT]

Mine adjusted itself all the way out til they weren't able to close back. Had to cut the drum open with a torch.

[racerop]

I just pulled and pulled until mine came off of my k20.
Very frustrating and scary to say the least, because of being on
Jacks stands. The drum on mine had bad grooves from metal
To metal contact. I wish I had pictures to show
How bad they were.

Good luck!!! Be safe

[weq92f]

In the past, I have used a universal puller with really long "arms" to successfully remove stubborn drums/discs...

YMMV

[GASoline71]

That "hammer" in your pic you posted isn't going to do anything if that's the one you were using. You need a no kidding BFH. 5 lb. or 8 lb. sledge. And start swinging.

Gary

[Stocker]

^^ Good eye, Gary, I completely missed that.

[franken]

A claw hammer and mechanic work should never mix but that's another story.
Put a big enough puller on the drum and it'll take the shoes with it. Since the drum comes out 2" chances are its the brake hardware the shoes are hung up on and beating on things isn't going to help much.
In the absence of a puller (borrow from parts store?) my thought is some threaded sleeves on a few lugs and studs in the sleeves to a bar with the bar center riding on something to the spindle, which makes a crude puller.

[demian5]

1. Beat on back of drum with BFH.
2. Try and rotate drum.
3. Repeat steps 1 and 2 until drum is removed.

Is there a indentation for the adjuster hole (same shape as the drum inspection holes) in the lower part of the backing plate?

I had to remove drums from an old British car once that were rusted on from years of sitting.

Use this as reference for where the adjuster is and drill a hole. You can force adjust the star without holding the lever with one hole drilled.

http://67-72chevytrucks.com/vboard/s...d.php?t=443837

http://67-72chevytrucks.com/vboard/s...d.php?t=660022

[SuperChief]

That is amazing..Wish I would have done that when I worked in a shop!!!