Brakes running hot, unable to adjust to spec

[stupidwhitecat]

Hey all, I need some help with brake adjustments. One of my drums is running hot. A little while ago I singled out my truck. While flipping the hubs I went through and replaced all the axle seals and bearings. Since then I have been monitoring the hub temps with an infrared thermometer. Since it was my first time messing with the bearings I wanted to make sure I did everything right. While I was in there I check the wheel cylinders for leaks and examined the pads. Regrettably I did not check the specs of the brakes or make any adjustments while everything was apart. While I was monitoring the hub temps I noted the drivers side rear drum was running considerably warmer than the rest. I was not having any noticeable issues with braking. So I downloaded the manual for the major and minor adjustments. I followed the directions removing the inspection window on the drum and starting at 5 o’clock used a feeler gauge to adjust the gap to spec. Rotated the drum to 1 o’clock to do the top of that shoe and at least found the source of the hot brakes. When initially checking the gap I could not get the smallest gauge in my set between the shoe and the drum. And even after adjusting the top nut both full clockwise and counter clockwise I got no noticeable change in the gap. I did not have the time to pull the hub and drum off that day. I am not sure what do next. The only info I have found regarding adjusting the shoes had to do with performing the same procedure I just did. I will pull the hub and drum to look for any obvious issues but what is the next step in adjusting the gap if the rear adjustment nuts didn’t get it to spec???

 

[gimpyrobb]

The bottom adjuster is on an eccentric bolt. If the bottom adjuster is all the way up, it can push the top of the pad into the drum.

 

[The King Machine]

Are you getting higher temps on the outside of the drum where the shoes make contact?

Or are the higher temps in the center where the bearings are?

After just flipping the hubs, I'm suspicious you may have over torqued the bearings or there is a problem with one of them.

 

[stupidwhitecat]

Are you getting higher temps on the outside of the drum where the shoes make contact?

Or are the higher temps in the center where the bearings are?

After just flipping the hubs, I'm suspicious you may have over torqued the bearings or there is a problem with one of them.

I am shooting the temp gun directly at the brake drum from under the truck near the inside of the wheel. The hub temps are fine.

 

[stupidwhitecat]

The bottom adjuster is on an eccentric bolt. If the bottom adjuster is all the way up, it can push the top of the pad into the drum.

OK this could have something to do with it. When looking at the bottom adjuster it had a "dot" indicator on one side. This was at 3 o'clock initially. When I started I checked the gap at the bottom first. It was out of spec, the gap was too close. To get to spec I had to adjust the bottom counter clockwise to 12 o'clock. So if that is that is why the top of the pad was so close, I still do not understand how to adjust them so they are both in spec??

 

[Kaiser67M715]

adjust them a little at a time, especially if they haven't been adjusted correctly in a while.

what I did for mine, was adjust the bottoms, then went to the top, while rotating the drum, once it started to drag, I would back off the bottom a little bit, still while turning until the drag went away. I would keep doing this until I got a .020 at the top, then I would adjust to .015 bottom, and finally .015 at the top. or rather finally adjust for slight drag with top adjuster.

I haven't driven on mine yet, but as it sits right now, the pads are about equidistant from the drum all the way around

 

[stupidwhitecat]

Well I got them adjusted to spec. I had to do the opposite of what the TM said. I had to adjust the top of the shoe first, then move to the bottom. Then I went back and forth until both were in spec.

 

[saddamsnightmare]

July 13th, 2015.


Did you replace all the hoses in the brake system while you were flipping the hubs? Sometimes the older brake hoses have an inner and outer layer that separates, and when you apply the brakes the inner layer backs off, but when the pressure drops for the brakes to release, the inner layer often flops in and prevents the hydraulic fluid from getting out of the wheel cylinders, causing dragging or sticking brakes.

Unimogs are prone to this when they get old, and I would suspect your deuce or 5 ton may be likewise having a release problem. Just a thought.....