Rear Drum Installation Problem 64

[elane352]

Greetings,

I have searched prior posts and have not seen anything yet that would address my problem. I apologize if there is something out there and I missed it.

I am wondering if I have ordered the wrong rear brake shoes. My problem is that I cannot get neither a new drum I purchased or the old one to slip over the threads and go all the way back onto the backing plate. A minute portion of the shoes is interfering.

Background

1. I removed the old drum, hardware, and the shoes (only worked on the passenger side rear wheel so far).

2. I replaced all hardware, including the wheel cylinder and the self adjusting pieces (see the 1st pic).

3. The prior owner converted from 6-lug to 5-lug.

4. Brake Shoes - Wearever, 2 inches wide, from Advance Auto; part # is: S228.

4. Drums - Wearever, part # YH1402254. from Advance Auto. The max diameter on the old drum is 11.09 inches. I believed that the new Wearever drum had the same diameter when I placed the order. I see this written on the new drum:

"Max * Dia * 281 * 69MMW5."

I have pictures of both drums (old one is black; new one is silver).

I was concerned initially that maybe I was using an incorrect drum due to not seeing 11.09 inches anywhere. But given that both the old and new drums will not clear the brake shoes, I began to thinks the shoes or the shoe placement were/was the issue instead of the drums.

The emergency brake is still off. The adjuster is closed.

[elane352]

I hit the post button by mistake before finishing up. So I did not get to attach the pics. Here they are.

Thanks ahead of time.

Edward

[The Rocknrod]

Is there an adjustment wheel at the bottom of the backing plate to reduce the overall diameter of the brake pads?

[elane352]

I did some online research this morning. Could be my problem?

"....brake cylinder has too much air or fluid in it causing the brake shoes to be pushed out too far. Then the brake drum will not go back on. If you crack the brake cylinder bleed screw open (with the appropriate tube and "catch" bottle for any fluid that might leak out), squeeze the brake shoes inward with your clean hands, then close the bleed screw. The brake drum should not go back on smoothly. Bleed that brake,...……"

I previously replaced the brake lines and have not bled the system yet.

[elane352]

Rocknrod, I just saw your comment after I posted some info. Let me check.

[elane352]

RocknRod,

I am thinking that you meant the silver adjuster at the bottom in the pic right?

I believe that I have it closed to hopefully have the shoes in instead of out.

Let me know if I misinterpreted things.

Edward

[The Rocknrod]

If thats all the way in and then open the bleeder on the wheel brake cylinder and squeeze em in by hand (the brake pads) they should slide easily inward toward the center (due to the springs) out outward via the wheel cylinder. If that doesnt help, then I'm stumped. Of course I hate drums so much I went with disc all the way around.
When I was a kid I worked at a tire dealer. They used to measure the ID of the drum, and the arc of the pads. They had a machine that arc 'ed the pads to match the drums.

[jayoldschool]

I never use the window. Drum off, adjust, drum back on to make sure the drag is correct.

[The Rocknrod]

And that's true about air in a hydraulic system (brake being that) what you posted earlier. If it gets hot it expands, unlike "some" hydraulic fluids (not all) depending on temps of course.

[cj847]

I would open the bleeder, since you have replaced lines and will have to bleed.
Also, occasionally I will find that the shoes do not butt up to the post at the top because it is hung up somewhere else. From the first pic that appears to be the problem.

[The Rocknrod]

Let me know if you want me to move this to suspension area: https://67-72chevytrucks.com/vboard/...splay.php?f=25
May have better luck?

[elane352]

Okay to move to Suspension.

Thanks to everyone that chimed in. I will get back on this after I finish the work from home day.

Edward

[elane352]

Problem resolved; I had to enlarge the diameter of the 5 drum holes to 9/16 inches.

After getting stumped with the passenger side rear wheel (the one I showed pictures of), I worked on the driver side rear wheel and had no problems getting the new drum on.

I then went back to the problem (passenger side) and removed everything I had initially installed to see if I could slide the new drum onto the backing plate with no shoes on. Of course the old drum slid on without a hitch. The new drum would not. It got hung up on the studs. After slightly enlarging the drum's holes, I put the shoes on to see if the new drum would then go on. It did.

So all is good. One drum needed modifications and one did not. Thanks to all of you that shared advice.

Eddie