Why after turning are my drums still dragging in certain "spots"

[nicksfj-40]

1973 FJ40 4 way drum.

I rebuilt the front axle and decided to replace all of the brake stuff and the TRE's. I had my drums turned at Napa and reinstalled everything to begin adjusting the brakes. I put on the drum and then the wheel and tire. With the lugs finger tight it would drag bad in certain spots. Once I snugged them down a bit it quite. So then I torqued the lug nuts, started adjusting, and it drags in certain spots again like it is out of round? Are you supposed to have the wheel and tire installed when you adjust, or is it just supposed to be the drum? I don’t have the two screws that hold the drum on the hub, are those necessary?

 

[Fast Eddy]

You don't need the two screws.

Once you get it all together, adjust and bleed the brakes. Then they should not drag. If they do, they're probably warped. They can get warped after they were turned. It sucks, but it happens.

 

[Pin_Head]

Drum brakes drag normally when they are properly adjusted, especially when new.
You have the wheel and tire installed when adjusting.
You tighten each adjuster until you can't turn the tire. This centers the shoe in the drum.
Then you loosen the adjuster by 3 clicks and see if you can spin the tire one revolution by hand. If not, loosen one more click and try it again.
Whether the drum is too warped to use is a separate issue. If you feel pulsation on braking, then it is bad.

 

[myquestoyota]

Find a shop that puts the proper radius on the shoes. They call it arcing the shoes. A lot of the well established machine shops do this. When I rebuilt my boat trailer I had the drums turned and the machine shop guy told me to bring my new shoes in to arc them to fit the drums. Worked wonders.

 

[cjgoode]

Are we talking about rubbing a little while rotating in certain parts, or are we talking spins freely for part of the rotation and hard to turn for the other part. I have never had drum brakes rub evenly for the full rotation, I adjust them to the first start scraping any part of the drum then back off till I hear nothing. Also make sure wheel weights or parts of the rims are not hitting anything.

 

[amaurer]

I too have never achieved a perfectly "rub free" brake adjustment. You're talking about a very fine adjustment (you're turning the adjusters by ~1/20th of a turn) and you can't expect a big cast iron thing like a brake drum to have tolerances that tight, even after turning.

I adjust them until the wheel will complete a full rotation by hand (as Pin Head says) and figure any spots that rub are going to get worn down in the first 100 miles.

 

[nicksfj-40]

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So I dont turn the whell while adjust the shoes out? I just adjust them out until they dont turn, then back them off until it spins with a tiny bit of drag?


So far I spin, I click, I spin, I click, I spin, I click. Then I hear a small rub for a second (once they start getting close to the drum, if I keep expanding them and spinning the tire, it will stick in the rub spot. I can pull the tire out of that area and the tire will still spin somewhat.

What does centering mean? Maybe that is my issue.

 

[cjgoode]

I adjust one clicker like you do till I hear it rub then back off one click so it does not rub, then I do the other adjuster on that wheel, then come back and to the fist one again. When I am done both adjusters are 1 click away from hearing anything rub. That has always seemed close enough to give good pedal with no rubbing when brakes are not applied.

 

[Fast Eddy]

What does centering mean? Maybe that is my issue.

Don't spin-click-spin... Adjust them tight so the wheel won't even turn, then back off three clicks like the man said.

You're going to need to readjust them after some small number of miles anyway, so just get them close.

 

[nicksfj-40]

Roger that. I will give it a shot and report back.
I was intimidated about doing a disk brake swap, but after doing a rebuild on the axle, I see that all you do is chnage out the axle ends and reinstall with the disk brake junk...Maybe next time.

 

[Pin_Head]

The drum brakes work fine up to 37 inch tires. People just don't like to adjust them properly. The proper way is to adjust them tight until the wheel won't turn and then back off 3 clicks. You should be able to throw the tire a complete rev after that. If not back off another click. They will rub after this, but it is normal.

 

[nicksfj-40]

Okay. Thanks. I appreciate all of the replys.

 

[nicksfj-40]

This worked perfectly once done as you all described. I locked up the tires and the damn thing didnt pull one way at all.

Thanksl for all of the help.

 

[lostmarbles]

Are you supposed to have the wheel and tire installed when you adjust................... I don’t have the two screws that hold the drum on the hub

Hell YES!

With the screws missing you most certainly do need to have your wheels on (and the wheel-nuts tightened) when you're adjusting your brakes. Otherwise you're wasting your time.

And you should be rotating the wheel for each "click" of the adjustor mechanism to see EXACTLY when it starts dragging.