Can't Get One Drum Off

[DXTAC]

Got the passenger side off with minimal problem but the driver side won't come off. The drum is loose but caught on the ridge caused by worn brakes. Any suggestions? The TM states that their is a window either on the drum face or backing plate. It looks like the writers in the "Ivory Tower" forgot to consult the mechanics and/or suppliers! Their are also no knock-outs, rubber plugs or anything of any type to allow you to access the adjuster. I am getting new drums so do I just keep beating on it?

Thanks,

Derek

 

[blybrook]

If you don't have an adjuster plug at the bottom of the backing plate, I'd continue to beat on the drum, or get out the blue wrench and cut it off.

I have yet to see a backing plate without the plug or access hole when dealing with drum brakes. Sometimes there is a punch out that you can remove to gain access and then seal with the rubber plug, but that's only if it was never properly serviced from date of manufacture.

HTH

Bill

 

[DXTAC]

Just got back from visiting the mechanic at the local Chevy dealership and he told me to keep whacking at it. Best idea was to use a 2x4 around the drum itself and beat like mad with the heaviest hammer I have.

Their are DEFINITELY no knock-outs, rubber grommets or anything like that on either the backing plate or on the face of the drum. Solid metal too, no indents or areas that even look like they were made to be chiseled, hammered or otherwise removed.

I'll keep at it!!

Thx,

Derek

 

[augiedoggy]

I've had to use 2 prybars on opposite sides of the drum and work it back and forth. Usually wind up replacing brake hardware, also i'll use a die grinder to knock off the rusty edge on the drum (wearing a respirator of course) if not replacing the drums. Good luck!

 

[Recovry4x4]

Make your own hole in the drum to adjust them down. Shoe damage and hold down hardware damage will occur if you keep prying.

 

[jimm1009]

You shouldhave an adjusting hole (actaully a slot) there at the bottom.
Take a small pick with a flashlight and lift the adjusting arm for the parking brake and turn the star wheel backwards to help retract the shoes inward.
Unlesss the starwheel is frozen you should be able to do this and this will let the shoes come in far enough to clear the groove in the drum.
A cheaper way rather than bending the brakes and possibly the backing plate
which are hard to find, is to crack the drum using a large chisel and hammer but then you will need a new drum too.
Hope you can move you adjustment. NOTE: The adjusting arm rolls the star wheel downward in order to adjust the threads outward so you have to rotate the wheel upward no matter which side fo the truck you are on. One side is left hand threads and one side is right hand threads but the wheel go up and rates towards the center of the truck to loosen. If you can imagine the drum removed and you are looking at the adjuster from the rear of the truck looking forward. the wheel would rotate clockwise on the left side and counter clockwise on the right side as you are looking down the shaft of the adjuster.

Let us know what happens.

jimm1009

 

[blybrook]

I will mark this one down as the first unit that doesn't have any access holes. Appreciate the information.

The idea about busting a hole in the drum to adjust would be the way to go since you plan to replace anyway. Good luck with the repair.

 

[319]

From the back of the backing plate, grind or chisel the head of the pin that retains the brake shoes. You sholud be able to pull the drum off easier.

 

[justinwregier]

I had this happen to me, one side practically fell off and the other was impossible! I do recall there being a curved bean shaped slot inset on my drum but I didnt have success with this route because it wasnt stamped out of the cast like the civy model?

Eventually I beat the rear drum like I could buy spare parts for cheap at the auto store (which I did) with a short sledge hammer. My situation for repair was due to a seized drum already though so the internals got swapped out anyway. After a few minutes of random swings the whole drum just gently came free with some turning.
If you do use force; sledge hammer, pry bars, kicking and screaming... be sure to be careful with the backing plate like mentioned already.

Good luck

ps. take a good quality photo of the internals on the good side you got off before you remove any springs or shoes... its much easier to view on a laptop than getting up and looking at the other side of the truck

 

[wikallen]

There has to be an adjuster slot. How else would you adjust the brake?

Crawl under the truck, and take a picture of the brake plate, and post it here.


I nice big dead blow hammer beating on the edge while a prybar keeps the other end from going back in might do it too.

 

[DXTAC]

Here ya go. Now this has got me wondering about the NOS drums I just bought from Saturn Surplus??? Maybe I should have gone through NAPA?!?!?!?!

Derek

 

[burbn10]

Here ya go. Now this has got me wondering about the NOS drums I just bought from Saturn Surplus??? Maybe I should have gone through NAPA?!?!?!?!

Derek

That's wild. Never seen that before...

 

[jimm1009]

Could it possbily stiill have the flat rubber plug installed and a small bit of dirt over it to where you are not seeing it?
The military has to use OEM parts by contract (or at least did) and all the GM backing plates have the slot for adjustments.

Perhaps the rare occasion where they purchased a backing plate from an aftermarket place for "field expediency"?

I would like to see a close-up pic too. Look closely at the 6 o'clock position.

In the event that it is not there and is proven, installing a neatly cut slot for future adjustments could be in order. Then you may not have to bust anything up to get it apart.
If you want measurements for making a slot let me know and I can get them tonight as I have an axle removed and sitting on stands right now (for a few weeks).

Just a little food for thought.

jimm1009

PS: WTH, I have never seen that one either...pics popped up while I was adding my reply.

 

[blybrook]

I've never seen backing plates look like that before. Probably never got stamped in the factory.

As mentioned earlier, cut off the two pins that hold on the brake shoes with a grinder or a punch. That should free it up. They look like little divits on the right and left hand side of the axle tube.

 

[DXTAC]

The last pic is a close-up of the 6 o'clock position on the backing plate right where the adjusting screw is located. I'm wondering if these drums are just from the factory and are original? Maybe the replacements will have a window in the drum, I hope!!

Derek

 

[burbn10]

The last pic is a close-up of the 6 o'clock position on the backing plate right where the adjusting screw is located. I'm wondering if these drums are just from the factory and are original? Maybe the replacements will have a window in the drum, I hope!!

Derek

Shouldn't have a window in the drum. It would be in the backing plate.

 

[jimm1009]

Stop- don't break anything just yet

I will load a pciture of your "fix" don't break your drum yet, unless you just want to.
Pics to come in 5 minutes or less.

jimm1009

 

[Recovry4x4]

Lots of the 73-87 Chevy half tons have the knockout plug (not knocked out) in the drums. I'd say most of them from my recollection unless it had the skinny shoes. I'd take a 4" sander to the drum just under the lip and clean up that rust a bit. I'd bet a tootsie roll the indentation will show up. I can't say why but GM did put them in the drums.

Edit; forgive the crappy pic, just went out into the back 40 with a cell phone for this one. Shows you what and where I'm talking about!

 

[DXTAC]

Shouldn't have a window in the drum. It would be in the backing plate.

The TM states the window will be in either the backing plate or the drum. I don't know if THIS link will work but it shows it on the drum of the M1009. TM 9-2320-289-20 8-5. DRUM, HUB, AND WHEEL BEARINGS MAINTENANCE.

Thx,

Derek

 

[jimm1009]

Guess what I found.

I purchased a N.O.S. axle from Builder 77 about 5 days before he was called home to help wathc over the rest of us.
I installed the axle but used my existing brake drums as I did not feel like cleaning the red finish off that day while I was in such a hurry.
Guess where the slot is (are), not in the backing plate but in the drum.
Here is a picture of the slot outlined in dust.
I also checked my O'Reilly's replacement drums and the also have the slots as well.
Punch this little sucker out with a 1/4 punch and you have your access hole (slot) for backing off that little wheel.
You need two long slender tools and a light to back of the adjustment wheel.

Jimm1009

In going back to your picture of the drum, I think that I see the plug at your 7 o'clock position but
You should be able to find it pretty fast with a small steel brush or some sandpaper.