Rear drum brakes - proper adjustment procedure(s) (1 Viewer)

Joined
Oct 12, 2004
Messages
3,060
Hi everyone,
I have done a good amount of "searching" threads here to find a definitive rear brake thread. Most of the threads that I have found are lacking some details specifically related to the adjustment process.
I recently had to replace the rear shoes on my 87 FJ60 since they were worn and actually starting grinding into the drum. I was able to successfully have the drums cut and the rear brakes were reassembled with new shoes, hardware, and wheel cylinders.
Just prior to replacing the above noted parts, I noticed that the brake pedal was a bit "low" and the brake performance seemingly declined. I attributed the decline in brake feel to the extremely worn rear shoes. When the brakes are working perfectly, I could lock up the tires....now I can't.
Upon replacing the parts, there is seemingly no improvement in brake feel. I have found a patchwork of threads noting that a special tool is needed to properly adjust the rear brakes, what is the "special" tool? Others have noted using two screwdrivers in concert, would that be successful? How do you "properly" adjust the brakes?
I will be replacing the brake master cylinder for good measure, since it has been probably close to twenty years since I last replaced it.
I am at a loss at this juncture in determining if the master is bad or the brakes are simply out of adjustment. Any ideas?


Thank you!
 
Joined
Feb 5, 2020
Messages
235
Location
Harpers Ferry, WV
Here's what the manual says:

1606964166780.png


With that being said there's no special tool. You just need one screw driver to rotate the adjuster star, you can only rotate it one way (upwards IIRC). If you do it by the book, then you'll need two screw drivers, you'll have to push the keeper away from the adjuster star with one screw driver and then rotate the star to loosen it. I haven't tried it this way, must of the time I just spin the wheel and adjust till it starts to drag or is about to start. There's a lot of feel involved with it.

Also check you parking brake cable as well, mine was tighten so much before I replaced the shoes and drums that they weren't disengaging all the way, as in still having tension on the springs.

All that being said, my FJ62 was incredibly difficult to get adjusted. I still don't think they're dialed in right. So, I'll probably mess around with them again soon. I might try to book method.
 

OSS

Joined
Jun 30, 2017
Messages
3,327
Location
Oblivion
New shoes and freshly lathed/turned drums need some time and braking before they seat in and grab properly.

Adjusting the rear brake is easy. Just pump the e-brake handle full pulls several times. It's integrated into the adjusters.

Messing around with the adjustment star wheel through the backing plate access hole is only necessary to release the tension on the shoes if the drum won't come off. Don't use it to set brake tension - that's what the E-brake is designed to do.
Using the e-brake to set the correct shoe distance guarantees you won't over tighten them. Trying to adjust the shoes via the backing plate access hole pretty much guarantees you'll set them too tight
 
Joined
Feb 5, 2020
Messages
235
Location
Harpers Ferry, WV
New shoes and freshly lathed/turned drums need some time and braking before they seat in and grab properly.

Adjusting the rear brake is easy. Just pump the e-brake handle full pulls several times. It's integrated into the adjusters.

Messing around with the adjustment star wheel through the backing plate access hole is only necessary to release the tension on the shoes if the drum won't come off. Don't use it to set brake tension - that's what the E-brake is designed to do.
Using the e-brake to set the correct shoe distance guarantees you won't over tighten them. Trying to adjust the shoes via the backing plate access hole pretty much guarantees you'll set them too tight

Yeah, I forgot to mention the E-brake adjuster. When I was having trouble with mine, I gave up and just backed up the star wheel and just sat there and yanked the e brake a bunch. But, I really think the brakes aren't adjusted correctly, you have to get each side close before you can rely on the E brake to adjust them. Otherwise, if one tightens up fully before the other, well, the e-brake cable isn't going to adjust the other side. At least, not in my case because right now, I'm getting some brake steering whenever I hit the brakes with some gusto.
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,035
Location
Charlottesville VA
Make sure the brake shoes are slightly snug against the drums. Do this by pulling and releasing the hand brake several times. Or you may be able to put your hand on the bell crank or parking brake cable that comes into the bell crank behind the brake. This moves the cable inside the shoes and activates the adjuster lever which turns and tightens the adjuster bolt which expands and pushes the shoes outward.
Do all this after you initially replace/rebuild your brake shoes. Put the truck on a lift or jack up the back axle and put on stands. Chock the front tires. Put in neutral. Turn the tire/wheel or brake drum as you activate the parking brakes until the shoes start to grab the drum but not locked tight.
Make sure the small cable inside the shoes is in the proper place. there is a pulley with a groove and a short (about 6 inch) cable that ride in the pulley and attaches to the bell crank hook at one end and the parking brake lever at the other. You can check to see the small arm (the adjuster lever) is working by removing the drum and pulling on the bell crank.

Also using a digital caliper measure the distance of the drum to make sure you're still within specs.
1606965525462.png
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,035
Location
Charlottesville VA
Yeah, I forgot to mention the E-brake adjuster. When I was having trouble with mine, I gave up and just backed up the star wheel and just sat there and yanked the e brake a bunch. But, I really think the brakes aren't adjusted correctly, you have to get each side close before you can rely on the E brake to adjust them. Otherwise, if one tightens up fully before the other, well, the e-brake cable isn't going to adjust the other side. At least, not in my case because right now, I'm getting some brake steering whenever I hit the brakes with some gusto.
this makes me wonder if you just have one side grabbing and the other side way too loose. Or is one wheel cylinder not working? If you pull the drums off and step on the brake gently you could get someone to watch to see if the wheel cylinders are working. Before taking off the drums make sure they are both dragging the shoes.
 
Joined
Feb 5, 2020
Messages
235
Location
Harpers Ferry, WV
this makes me wonder if you just have one side grabbing and the other side way too loose. Or is one wheel cylinder not working? If you pull the drums off and step on the brake gently you could get someone to watch to see if the wheel cylinders are working. Before taking off the drums make sure they are both dragging the shoes.
It's just grabs before the other side, I think it's only really noticeable during heavy brake just because it's the rear. I replaced everything on the brakes a couple months ago and was living with brand new wrapped drums for a while :bang: . Finally, got them turned and now I've been having issues. It was dark and cold when I was adjusting them, and my PO had the parking brake cable tightened all the way which I didn't realize for a while and lead to some frustration. So, as it sits I think the drivers side is way tighter than the drinkers side.

I just saw this in the manual and think I'm going check the bell crank adjustment once it's not so awful outside. Cause apparently something isn't right.

1606966464524.png
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,035
Location
Charlottesville VA
, you have to get each side close before you can rely on the E brake to adjust them
I'm not sure this is true. The parking brakes is supposed to move the adjuster lever each time you use the parking brake. It only has so much tension on it so not going to over tighten the adjuster. But you can make sure the lever moves and contacts the star dial and turns it a click with the drum off. You can also hear it click one time if you can pull the bell crank far enough and let go. It may be that one of your bell cranks is froze and therefore not letting the parking brake cable pull the adjuster lever. You can verify this by moving the bell crank by hand or grab the cable just before the bell crank and pull it hard and let go. Make sure the adjusting bolt on the bell crank goes all the way back to the backing plate.
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,035
Location
Charlottesville VA
Here's an image of the 2 screwdrivers used to loosen the brake shoes so you can remove the drum. the one angled downward pushes the adjuster lever away from the dial, basically unlocking it so it can loosen, the other one turns the dial.

Tightening can be done with just the one screwdriver on the dial and the adjuster lever click/slips and lets the dial turn.

1606968264747.png
 
Last edited:
Joined
Feb 5, 2020
Messages
235
Location
Harpers Ferry, WV
I'm not sure this is true. The parking brakes is supposed to move the adjuster lever each time you use the parking brake. It only has so much tension on it so not going to over tighten the adjuster. But you can make sure the lever moves and contacts the star dial and turns it a click with the drum off. You can also hear it click one time if you can pull the bell crank far enough and let go. It may be that one of your bell cranks is froze and therefore not letting the parking brake cable pull the adjuster lever. You can verify this by moving the bell crank by hand or grab the cable just before the bell crank and pull it hard and let go. Make sure the adjusting bolt on the bell crank goes all the way back to the backing plate.

My bell cranks are free. I rebuilt them a couple months ago. I know for a fact they weren’t sitting on the backing plate because the cable was over tightened like I said. What I’m not sure of now is that they’re properly adjusted. I’m thinking now that one side it to loose, meaning theres extra slack in the cable inside the drum and because of that it’s not adjusting the star automagically. I’ll rip everything apart next week and check.
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,035
Location
Charlottesville VA
I don't know of a side to side adjustment for the parking brake cable. I'm getting ready to replace mine and waiting for parts. Only adjustment info I can find is the adjustment bolt at the back of the bell crank, and the slack/tension adjustment on the pull handle. I can't find any info in the FSMs on installation or adjustment of the parking brake cable.

One other thought is to make sure the brake adjuster is cleaned of all dirt and brake dust and old grease and to grease it and make sure it's moving freely.
 
Last edited:
Joined
Jun 6, 2020
Messages
8
Location
Denver
Did this a couple months ago for a parking brake that was in op. Found this video super helpful.


In my case cable that linked the bell crank to the drum/adjusting mechanism had slipped out of its track, wasn't tightening the drums or the adjusting mechanism, circa 3:30 on that video.
 
Joined
Oct 12, 2004
Messages
3,060
Back to square one......
I thought they were adjusted correctly, but apparently not. When driving the truck around town everything seemed fine, except that it didn't brake as well as n did in the past. When I took it out on the highway. after about 15 minutes I noticed some vibration from the truck. Then when I would brake I would get a ton of vibration. At first I assumed that the the front calipers were sticking, but that was not the case. When I stopped I quickly realized that the rear drums were almost red hot, so clearly they are sticking.
How can the rear brakes go from seemingly adjusted correctly to being WAY out of adjustment in less than 20 miles? What am I doing wrong?


Thank you!
 

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,035
Location
Charlottesville VA
I recently had this problem...shoes grabbing and vibration at speed, overheating...smoking. Seems the adjusters can and DO over adjust with new brake shoes. The pins that hold the brake adjuster lever has slightly too much room. Causing the lever to grab too much. I shimmed mine out with a washer as suggested in this thread and so far seems to be working.

rear brakes over adjusting..... | Page 4 | IH8MUD Forum
 
Last edited:

g-man

SILVER Star
Joined
Sep 5, 2006
Messages
3,035
Location
Charlottesville VA
Because the shoes had overtightened against the drums...it was very hard to get the dial turned on the adjuster through the slot. Yes, I had the adjuster lever pushed away with a smaller screwdriver. Still, the shoes tight against the drum had pinned the adjuster tight. I eventually got the dial to turn with lots of pressure.
 

Users who are viewing this thread

Top Bottom