Chevy Suburban Hot Rear Brakes

Ray LeTourneau

Senior Member - Past Moderator
I'm looking for a little help for a friend.

Tow vehicle is a 2004 2500 Suburban. 8.1 with 4.10 gearing.

The problem is the rear brakes get extremely hot but ONLY while towing. He has had the brakes checked by a reputable mechanic and everything is good and there are no issues while not towing. He has had the rear diff fluid changed and checked again and all is good there.

Any thoughts?
 

jmgratz

Original Owners Club Member
Sounds to me like the trailer brakes are not working and the brakes on the truck do all of the stopping.
 

Manzan

Well-known member
Would most of the trailer weight on the rear axle due to an improperly set WD hitch make a difference? Along with trailer brakes not working. Not sure of the physics involved.
 

danemayer

Well-known member
I'm wondering how he knows it's the brakes getting hot. If the hubs are hot, it could be the brakes, or maybe something else - bearings?

Does this happen only in traffic where the brakes are getting a lot of use, or does it also happen on the highway where little or no braking is involved?
 

TeJay

Well-known member
Ray,
This has been a topic before but that's OK . When he says hot what does he mean?? If they are working correctly they will get hot but under normal situations they should not smoke or get steaming hot. If you do a couple panic stops they will be hot but not usually smoking hot. The heat is directly related to how much weight you are trying to stop. Just use some common sense on that issue. It's already been mentioned and they are probably correct that the trailer brakes may not be working and the truck brakes are doing all the work. Remember that brakes work because they are rubbing two surfaces (drum or rotor & shoes or pads) together to create friction to change all that energy of motion (truck/camper) into another form of energy and that's heat. When you inspect brakes the problems are not always obvious. Worn brake material and scored drums are easy to spot but glazed linings are not. Glazed linings result from overheating the material. The bonding agent used to make the material becomes chrystalized when it's overheated and becomes smooth or polished. At that point the linings are ruined and must be replaced. There is a difference between burnished linings and glazed linings. No glazed linings can't just be sanded or ruffed up with sandpaper because it's deep into the material. Bad bearing will overheat but they would overheat all of the time and just wiggling the wheel will tell you if the bearings are so bad that they are getting hot. Also a visual inspection will show the heat generated and worn bearings. As suggested have him check for correct hitch adjustment.

TeJay
 

Ray LeTourneau

Senior Member - Past Moderator
All great thoughts here. Because I don't see this friend but a couple times a year, I'll forward this thread link to him so he can see the replies. I did discuss the weak trailer brake possibility with him. He also said he checked the temps of the rear brakes with a non contact thermometer and they were beyond it's range. I forgot what that number was. Hopefully he'll become a forum member and he can respond as well. Thanks!!!
 

porthole

Retired
Bad master cylinder - contaminated fluid? That is where i would look first. Majority of the braking is done by the front brakes.

Parking brake cable issue? Don't remember if the 2004 got disc brakes but either style of parking brake will cause problems if sticking - hanging up..
 

Ray LeTourneau

Senior Member - Past Moderator
Bad master cylinder - contaminated fluid? That is where i would look first. Majority of the braking is done by the front brakes.

Parking brake cable issue? Don't remember if the 2004 got disc brakes but either style of parking brake will cause problems if sticking - hanging up..
Yes, they are discs. I'm hoping my friend will get signed in and reply this evening. He's pulling a small TT toy hauler. I'm not sure either but I think the parking brake is on the driveshaft???
 

katkens

Founding Illinios Chapter Leader-retired
Yes, they are discs. I'm hoping my friend will get signed in and reply this evening. He's pulling a small TT toy hauler. I'm not sure either but I think the parking brake is on the driveshaft???

The rear disc brake rotor has a cast brake drum on the inside of rotor , it functions as emergency brake.
 
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