Increased tire temperature New Aire

[islandnomad]

Photos Valor sensor and rim installation

[turbopilot]

Originally Posted by islandnomad

Turbopilot: It does mount on the rim.

Ok installation as expected

Maybe we are using terms differently. My definition of "rim" would be the outer edge of the wheel which is the primary interface between the tire bead and the wheel. I am using "hub" to mean the center section of the wheel, exclusive of the "rims".

In any event if the Valor sensor is stuck on the wheel "hub" it will be sensing the highest temperature in the whole tire/wheel assembly since it is rotating within an inch or so of the hot brake drum. I would expect to see high temperatures in that sensor location particularly since we are dealing with a steel wheel in that position versus an alloy wheel outboard. So 210F measured temperature from a sensor in that location seems about right, maybe even a bit low with heavy braking.

[islandnomad]

Turbopilot: I like your definitions wheel, rim and hub - makes it much easier to communicate. I understand your point about the proximity to the hub/brake. I need to re-confirm with Valor exactly what temperature, air or steel is being measured.


Again, my concern is the tire temperature and the degradation (reversion) of the tire from high temperatures. I would appreciate your thoughts on this.

[Dutch Star Don]

Maybe I'm missing something. I think some are skimming over all the pertinent information. The OP is seeing 210 degrees at the TIRE. In his original post, his sensor said 210 and then an IR gun verified the same temp at the rim and TIRE. I don't think it's a reading caused by the proximity of the sending unit to the steel wheel mount.

I realize that some tire monitors are estimating the heat since they're attached to the stem. My DP exhaust heats up the sensor on the right front tire of my toad and causes some high readings. I've also stopped at a rest stop in 100 degree weather and taken an IR reading of my tires, they've never been more than about 25-30 degrees above ambient air temp.

It just doesn't make sense to see 200+ degrees on a TIRE.

****Just did some more reading on the topic. A poster saw 186 degrees on his RV tires, but the outdoor temp was 111 degrees.

["007"]

The rear duel tires have brake shoes for stopping the coach which one of the rear duel tires has the brake shoes, inner tire or outside duel or both?
Is the brake shoe's releasing fully when your foot is off brake or is the brake shoe dragging on the wheel cylinder, heating up the tire.
Have you had any problems with heated brake fluid or does braking seem to fade at times?

[islandnomad]

Reply 007: Brake shoes/brakes/slack adjusters are on the rear inner steel wheels. Outer rear aluminum wheels with no brakes. As far as I can tell, the brake shoe releases when foot off the brake pedal. I have experienced no fading. Air brakes so no fluid to my knowledge. As mentioned previously, when the temp reaches +/- 150°, the temps rise relatively rapidly to alarm temp 176° and above which makes me wonder if defective steel rims/wheels are the problem: expanding with the increased braking heat resulting in incomplete release of the brake shoe. Thoughts ?

[islandnomad]

Reply Dutch Star Don: Agree that it not the proximity of the sensor on rim/wheel. Otherwise, IMO, all Valors would be alarming - at least with drum brakes/steel wheels and frequent braking. Ambient temperatures have never above 80-85°F, so far. If I recall correctly, the tire temps can be up to 20-25°F above ambient when going down the road.
It is the tire temperature rise causing potential degradation of the tire.


BTW: I have spent considerable time with Freightliner - via phone, Gaffney Service Center, FMCA Rally Perry. Most recent communication = there is not a problem. However, at the first occurance, Freightliner replaced the brakes so must have thought at that time there was a problem.

[twinboat]

Originally Posted by islandnomad

Reply 007: Brake shoes/brakes/slack adjusters are on the rear inner steel wheels. Outer rear aluminum wheels with no brakes. As far as I can tell, the brake shoe releases when foot off the brake pedal. I have experienced no fading. Air brakes so no fluid to my knowledge. As mentioned previously, when the temp reaches +/- 150°, the temps rise relatively rapidly to alarm temp 176° and above which makes me wonder if defective steel rims/wheels are the problem: expanding with the increased braking heat resulting in incomplete release of the brake shoe. Thoughts ?

The brake drum, not the wheel, would expand from heat caused by braking. There is at least an inch clearance between the drum and wheel so that they would never make contact.

If anything, you would have more clearance between shoes and drum when the drums get hot.

You should be able to see the gap between the shoe and drum by crawling under and looking. You will need to chock the wheels and reliese the parking brake.

You can even pull on the slack adjuster, parking brake off, by hand, to check for movement. If they are hot and dragging or binding, there will be no movement.

[islandnomad]

Twinboat: Thank you. That check has been done at Freightliner, Gaffney Service which I observed. Cold brakes. I will try checking when hot if possible. Not much clearance to crawl underneath.

[PaulTNaples]

Is it possible that the air bags are not fully inflated causing to much loading on the axel?

[RHoop]

One other thought, don't put too much faith in the readings from an IR gun, especially if you are shooting from several feet away. You can test the accuracy for yourself by aiming at other objects, or other parts of the same object, that should be at the same temperature.

[islandnomad]

Have conference call with Newmar and Freightliner tomorrow - will raise suggestions from the above posts. Hopeful I will get a more definitive solution.

[islandnomad]

Conference call Newmar & Freightliner. Suggested using engine brake in slow traffic, frequent braking etc. Same as suggested by Old-RVer in earlier post. Anyone else use their engine brakes in traffic ??

[NealC]

I use engine brake all the time to save the brakes unless in hydroplane conditions.