TrailManor Owner's Forum  

Go Back   TrailManor Owner's Forum > TrailManor Technical Discussions > Frame
Register FAQ Members List Calendar Mark Forums Read

Reply
 
Thread Tools Display Modes
Old 09-05-2008, 07:30 PM   #1
ShrimpBurrito
Site Sponsor
 
ShrimpBurrito's Avatar
 
Join Date: Jul 2006
Location: Sunny Beaches of Los Angeles
Posts: 3,233
Default Just changed brakes and bearings -- why are the hubs so hot?

I just did an overhaul on the TM wheels --- new brake assemblies (new shoes, magnets, springs, backing plate, everything), new drums, new bearings, races, and seals, and hand packed bearings with Castrol wheel bearing grease. Soldered the wires....one old wire nut connection was down to a few strands, and one wire going from one wheel to the other was very badly corroded.

After reassembly, I adjusted the brakes with the adjusting wheel so that I could barely turn the wheel, and then backed off until they were just dragging a bit. When I spun the wheel, I could hear brake drag for the entire revolution, but the wheel spins fairly freely with one hand, but definitely not as freely as with no drag. (which is what the Dexter instructions say to do -- adjust to a "light lining drag", whatever that means)

Then I went for about a 7-mile test ride, braking frequently, both at intersections, and manually braking the trailer via the controller while en route. When I got to my destination, both hubs were very hot (could only touch them for 1-2 seconds before getting very uncomfortable) and I could smell brakes.

So it seemed the brakes were too tight. I jacked up both wheels and adjusted the brakes to be less tight. So now when I spin the wheel, you can hear drag for part of the revolution, seemingly indicating a high spot on the shoes. I let the hubs cool off for about 30 min, then drove 3 miles. The hubs heated up again, but not as bad. After letting the hubs cool for about 90 min, I then drove the same 3 miles in reverse. The hubs got warm, but not hot -- about the temp as what they've been over the many thousands of miles we've traveled with the TM.

But then I drove back the 7 mile trip again, braking more than the previous 3 miles, but not as much as the first time doing the 7 miles. At the end of that trip, the hubs were again very hot and I could smell brakes, although probably not quite as bad or smelly, but still obviously too much of both.

So it seems my brakes are still dragging too much. I haven't touched the adjustment on my controller. I was going to lower the voltage and go from there, but first decided to wear them in first. But even at the controller's current setting (which is the maximum voltage on the Prodigy P3 controller), and after about 20 miles with new brakes, the wheels still don't come close to locking up during a hard stop. So I don't think the controller is set too high. And according to the controller display, there is no voltage going to the brakes while underway.

I don't think it's the bearings generating the heat because a) I smell brakes; b) the hubs seem to get hotter when I brake more; and c) I can't think of anything I could have done wrong installing the bearings. It was the first time I've changed the races, but not the first time I've repacked bearings. I tightened the castle nut tight, then backed off about a 1/4 turn....it's on there a little bit tighter than hand tight. The races are fully seated.

I think I'm just going to keep backing off the brake adjustment until I'm not generating heat, hoping I don't superheat the brake shoes or smoke the bearings in the process.

Any suggestions?

Dave
__________________
2000 2720SL & 2007 3124KB
2005 Toyota Sequoia
Twin Battle Born 12v 100Ah LiFePO4 (BBGC2) batteries, 300W solar on rear shell, Link 10, Lift kit, Maxxis 8008 225 75/R15 E tires
ShrimpBurrito is online now   Reply With Quote
Old 09-06-2008, 12:11 AM   #2
Wavery
TrailManor Master
 
Wavery's Avatar
 
Join Date: Jan 2022
Location: San Diego, California
Posts: 2,824
Default

Quote:
Originally Posted by ShrimpBurrito View Post
I just did an overhaul on the TM wheels --- new brake assemblies (new shoes, magnets, springs, backing plate, everything), new drums, new bearings, races, and seals, and hand packed bearings with Castrol wheel bearing grease. Soldered the wires....one old wire nut connection was down to a few strands, and one wire going from one wheel to the other was very badly corroded.

After reassembly, I adjusted the brakes with the adjusting wheel so that I could barely turn the wheel, and then backed off until they were just dragging a bit. When I spun the wheel, I could hear brake drag for the entire revolution, but the wheel spins fairly freely with one hand, but definitely not as freely as with no drag. (which is what the Dexter instructions say to do -- adjust to a "light lining drag", whatever that means)

Then I went for about a 7-mile test ride, braking frequently, both at intersections, and manually braking the trailer via the controller while en route. When I got to my destination, both hubs were very hot (could only touch them for 1-2 seconds before getting very uncomfortable) and I could smell brakes.

So it seemed the brakes were too tight. I jacked up both wheels and adjusted the brakes to be less tight. So now when I spin the wheel, you can hear drag for part of the revolution, seemingly indicating a high spot on the shoes. I let the hubs cool off for about 30 min, then drove 3 miles. The hubs heated up again, but not as bad. After letting the hubs cool for about 90 min, I then drove the same 3 miles in reverse. The hubs got warm, but not hot -- about the temp as what they've been over the many thousands of miles we've traveled with the TM.

But then I drove back the 7 mile trip again, braking more than the previous 3 miles, but not as much as the first time doing the 7 miles. At the end of that trip, the hubs were again very hot and I could smell brakes, although probably not quite as bad or smelly, but still obviously too much of both.

So it seems my brakes are still dragging too much. I haven't touched the adjustment on my controller. I was going to lower the voltage and go from there, but first decided to wear them in first. But even at the controller's current setting (which is the maximum voltage on the Prodigy P3 controller), and after about 20 miles with new brakes, the wheels still don't come close to locking up during a hard stop. So I don't think the controller is set too high. And according to the controller display, there is no voltage going to the brakes while underway.

I don't think it's the bearings generating the heat because a) I smell brakes; b) the hubs seem to get hotter when I brake more; and c) I can't think of anything I could have done wrong installing the bearings. It was the first time I've changed the races, but not the first time I've repacked bearings. I tightened the castle nut tight, then backed off about a 1/4 turn....it's on there a little bit tighter than hand tight. The races are fully seated.

I think I'm just going to keep backing off the brake adjustment until I'm not generating heat, hoping I don't superheat the brake shoes or smoke the bearings in the process.

Any suggestions?

Dave

One suggestion........Relax.

It's perfectly normal for new brakes to get hot and even a little smelly until they are broke in. One of the worst things that you can do to new brakes is to "Over stress" them. It's best to drive normally for the 1st few hundred miles. If you glaze the shoes during brake-in, you will loose a lot of your braking power and your brakes will over-heat more easily.

I would NOT recommend manual braking new trailer brakes. That generates a tremendous amount of heat because the trailer is trying to do the job of all 3 axles, including the 2 TV axles. Not a good thing to do to new brakes. That's sorta like getting your car out of the brake shop, racing down the street at 90MPH and slamming on the brakes.

Sounds like you've got it right. You won't get bearings over-heating on a 3-mile drive (unless they are really over-tight).
__________________
TrailManor Elkmont
640W solar- 230AH LiFeP04 Battery
Wavery is online now   Reply With Quote
Old 09-06-2008, 06:08 AM   #3
mtnguy
Guest
 
Posts: n/a
Default

Quote:
Originally Posted by harveyrv View Post
Sounds like you've got it right. You won't get bearings over-heating on a 3-mile drive (unless they are really over-tight).
In my case, I left my bearings too loose. I tightened the castle nut, rotated the wheel, retightened, and then backed off 1/4 turn. There was slight play in the bearings, which is the way I learned in my younger years. But the bearings were still running hot. I took it to a trailer shop to make sure everything was OK, and also to check the brakes, and the mechanic there took a lot of time adjusting the bearings when he put the wheel back on. He left the bearings tighter than what I had, and there was virtually no play with the bearings. The hubs run warm and equal side to side now.

Chap
  Reply With Quote
Old 09-06-2008, 08:56 PM   #4
ShrimpBurrito
Site Sponsor
 
ShrimpBurrito's Avatar
 
Join Date: Jul 2006
Location: Sunny Beaches of Los Angeles
Posts: 3,233
Default

The Dexter instructions that came with the TM and the Prodigy brake controller instructions both say to manually brake the trailer brakes using the lever on the controller during the break-in procedure. That's why I did that.

I pulled both wheels off just to triple check the bearings, raceways, tightness of the castle nut, and brake adjustment. This time, I remembered my infrared thermometer and took a baseline reading of 71 degrees at home. By the time we drove 5 miles in city traffic, the hubs shot up to 130 degrees, and the wheel was about 125. Very hot to touch, but not quite as hot as yesterday.

On the way home, I decided to turn the output voltage on the brake controller to zero, essentially disabling the TM's brakes. I again took a baseline reading before heading back, and they had cooled to 72 degrees. After 5 miles along the same exact route, the hubs heated up to 82 degrees. Much better.

So it seems the TM brakes were set too high, and the TM was pulling back on the TV during braking. So now I think I'm going to increase the controller voltage to just below the point where the hubs heat up. I can't think of any other way to do it, but I know running hubs at 130-150 degrees is not a good idea.

Dave
__________________
2000 2720SL & 2007 3124KB
2005 Toyota Sequoia
Twin Battle Born 12v 100Ah LiFePO4 (BBGC2) batteries, 300W solar on rear shell, Link 10, Lift kit, Maxxis 8008 225 75/R15 E tires
ShrimpBurrito is online now   Reply With Quote
Old 09-07-2008, 03:08 PM   #5
rtcassel
Site Sponsor
 
Join Date: Jul 2003
Location: MD
Posts: 410
Default are you using a boost setting?

If I use a boost setting of b1 on the Prodigy, the hubs get too hot.
Reference post http://trailmanorowners.com/forum/sh...0275#post40275
Does anyone out there use boost without getting hot hubs?
__________________
Tim
2004 2720SL TrailManor, 2 X T105, Trimetric 2030RV, TST TPMS
2003 Tundra Access V8 2X4 w/Tow Pkg
Equal-i-zer 1000, Prodigy, McKesh, UnderCover
rtcassel is online now   Reply With Quote
Old 09-07-2008, 03:54 PM   #6
ShrimpBurrito
Site Sponsor
 
ShrimpBurrito's Avatar
 
Join Date: Jul 2006
Location: Sunny Beaches of Los Angeles
Posts: 3,233
Default

Before I changed the brakes, drums, and magnets, I used the B3 boost setting on the Prodigy P3, and my hubs never got hot. I knew was settings were high, which was one reason I wanted to change everything -- I figured there was little braking reserve, which is a problem not only when towing but also in a break-away situation.

But my understanding is that the boost setting just refers to the initial output voltage, i.e. the voltage as soon as you step on the brake pedal. Voltage increases as you decelerate. No boost starts at 0 volts, B1 starts at 13% of output voltage, B2 at 25% of output voltage, etc.

My output voltage was previously set at the max -- 12+ volts. Plus the B3 boost. And again, my hubs never got hot with those settings until I changed all that stuff.

Dave
__________________
2000 2720SL & 2007 3124KB
2005 Toyota Sequoia
Twin Battle Born 12v 100Ah LiFePO4 (BBGC2) batteries, 300W solar on rear shell, Link 10, Lift kit, Maxxis 8008 225 75/R15 E tires
ShrimpBurrito is online now   Reply With Quote
Old 09-07-2008, 04:08 PM   #7
rtcassel
Site Sponsor
 
Join Date: Jul 2003
Location: MD
Posts: 410
Default

Perhaps the mechanical aspects of the new braking system are so much better than what you had on there before: magnets, wire connections, springs, shoe linings, pristine hubs, etc. Maybe the old parts' deficiencies were masked by the use of boost. I recommend trying it without boost. I did not understand why boost would contribute to hot hubs, but the tech person I talked to at Tekonsha did not seem to want to talk about it. She just said that if it makes the hubs hot, then do not use boost.
__________________
Tim
2004 2720SL TrailManor, 2 X T105, Trimetric 2030RV, TST TPMS
2003 Tundra Access V8 2X4 w/Tow Pkg
Equal-i-zer 1000, Prodigy, McKesh, UnderCover
rtcassel is online now   Reply With Quote
Old 09-07-2008, 04:51 PM   #8
ShrimpBurrito
Site Sponsor
 
ShrimpBurrito's Avatar
 
Join Date: Jul 2006
Location: Sunny Beaches of Los Angeles
Posts: 3,233
Default

Quote:
Originally Posted by rtcassel View Post
Perhaps the mechanical aspects of the new braking system are so much better than what you had on there before: magnets, wire connections, springs, shoe linings, pristine hubs, etc. Maybe the old parts' deficiencies were masked by the use of boost.
I agree.

Interesting that Tekonsha recommended no boost. In Dexter's instructions, they say to set the controller so that 2 volts goes to the brakes at initial braking, gradually increasing to 12 volts.

Prodigy's instructions say that without the boost, voltage starts at zero. So that doesn't seem consistent with what Dexter recommends for their brakes.

But I think if you have good braking and cool hubs, all is good in the world. I'm going to remove the boost as you suggest and go from there. What power setting (1 to 12) is your P3 set to? The Prodigy instructions say to start at 6 before adjusting......

Dave
__________________
2000 2720SL & 2007 3124KB
2005 Toyota Sequoia
Twin Battle Born 12v 100Ah LiFePO4 (BBGC2) batteries, 300W solar on rear shell, Link 10, Lift kit, Maxxis 8008 225 75/R15 E tires
ShrimpBurrito is online now   Reply With Quote
Old 09-07-2008, 05:07 PM   #9
Bill
Site Team
 
Bill's Avatar
 
Join Date: Feb 2003
Location: The mountains of Scottsdale, AZ, and the beaches of Maine
Posts: 10,088
Default

I don't use a Prodigy, so this is an honestly ignorant question. The posts above make it sound like the boost setting applies some small voltage to the brakes even when the brake pedal is not depressed. Can this be true? Say it ain't so, Joe!

Bill
__________________
2020 2720QS (aka 2720SL)
2014 Ford F-150 4WD 5.0L
Bill's Tech Stuff album
Bill is offline   Reply With Quote
Old 09-07-2008, 05:32 PM   #10
ShrimpBurrito
Site Sponsor
 
ShrimpBurrito's Avatar
 
Join Date: Jul 2006
Location: Sunny Beaches of Los Angeles
Posts: 3,233
Default

Quote:
Originally Posted by Bill View Post
The posts above make it sound like the boost setting applies some small voltage to the brakes even when the brake pedal is not depressed. Can this be true?
Not as far as I can tell. The Prodigy manual says, "Each incremental boost setting increases the sensitivity of the P3's inertial sensor, enhancing the participation of the trailer brakes during a braking event."

But the it says, "With the boost off, during a braking event, the power to the brakes starts out at zero and increases with deceleration. With the boost on level B1, during a braking event, the power automatically starts out at approximately 13% of the power setting and increases with deceleration. With the boost on level B2 or B3, during a braking event, the power automatically starts out at approximately 25% of the power setting and increases with deceleration."

It doesn't specifically state the difference between boosts B2 an B3, although it recommends B3 for bigger trailers.

Dave
__________________
2000 2720SL & 2007 3124KB
2005 Toyota Sequoia
Twin Battle Born 12v 100Ah LiFePO4 (BBGC2) batteries, 300W solar on rear shell, Link 10, Lift kit, Maxxis 8008 225 75/R15 E tires
ShrimpBurrito is online now   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 07:13 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 2022 Trailmanor Owners Page.