Normal or trouble brewing?

[Ck2hans]

The TPMS shows my inside passenger dual wheel is running 20 deg hotter than the rest of the wheels and the PSI is running 1-2 PSI higher than the rest.
Is this normal or is there trouble brewing?
Chuck

[Fratto]

We leave from Taos headed to Amarillo tomorrow. I will pay more attention to the temperatures. On the drive axles, I would think that if it was an oil issue it would show up on both sides. If it was a bearing issue, I would think that some of the heat would migrate to the outer dual. I know that the outer dual probably has more airflow / cooling but surely it would not be the same temp as the drivers side when the inside dual is warmer? I would think that a dragging brake or other issue would create much more than a 20 degree delta.

Is your TPMS internal or screwed onto the stem? If the latter, can you swap sensors and see if there is a calibration issue?

Has this 20 degree delta been constant, did it just show up?

[Ck2hans]

Mark:

Good input, the TPMS are external. I will swap the sensors to see what happens. Might crawl under the coach (with jack stands) when I get home and back off the brake adjuster a tad to see if that makes a difference.

Chuck

[Ck2hans]

UPDATE
Swapped the TPMS on the passenger duals (inside to outside and Vice versa). The temp still shows 18-20 deg higher on the inside (which is now reading as the outside) and still 2–3 PSI more. Sooooo I am guessing the brakes are starting to drag on that wheel. Will attempt to adjust it the next time I get under the coach.
Chuck

[PrevostNewbie]

Chuck, i think you have auto slack adjusters.

[Ck2hans]

Mike:
You are correct, when I think about it about 6 years ago I had a similar issue and believe it was the same axle. I backed off the auto adjuster a few clicks and that fixed the problem. Going to get under the coach and back off the adjuster a couple of clicks again and see if I can get another 6 years out of it.

[Fratto]

Good Morning ... back in the Texas heat. Here are my tire temperature observations from Taos to Amarillo and Amarillo to DFW.

Coming down the canyon from Taos to Espanola using the trans retarder and some brake: Front tires normally in the low 120 range or in the high teens. Drives in the high 90's to the low 100's depending on sun exposure. Tags in the 130 range. However when stopped at the various stop lights in Espanola after the the descent, the drivers tag went to 150 and the passenger to the 140's. 30 to 45 minutes later with highway driving temps were back in the 130's. Could be that the drivers side has the muffler, radiator, trans cooler (with retarder running in the 230 range) etc. contributing to heat?

From Amarillo to DFW: Front and drives same as before. Tag on the drivers side mid 130's and passenger high 120's. Although it takes and hour to two to get to these temps. However as we get into the DFW stop and go traffic, the tag temps both went into the 140's sitting at lights. At this time, we also were running the generator and you guessed it, the exhaust pipe also runs past the drivers tag. While checking into the RV park and idling the drivers tag goes to 150 and the passenger to 140's.

I wish I had paid more attention to the temps rather than just the pressures in the past. Now I am not sure if this has always been the case or if it is something new. Anyway, with highway air flow, tags can in the 130's but when stopped the temperatures climb.

Chuck: On the drives, mine were always the same temp +/- 2 degrees or occasionally 4 degrees different.

I have Prevost Nashville researching the caliper issues and if I learn anything I will let you know. We will likely stop by there on the way to or from Busapalooza in Petosky in September.

[PrevostNewbie]

Mike:
You are correct, when I think about it about 6 years ago I had a similar issue and believe it was the same axle. I backed off the auto adjuster a few clicks and that fixed the problem. Going to get under the coach and back off the adjuster a couple of clicks again and see if I can get another 6 years out of it.

I have manual slack adjusters on my bus, i am curious as to how you can back off a few clicks and not have them go right back as soon as you apply the brakes.

[Fratto]

Good Point :-)

[Ck2hans]

Mike:
Don't have a good answer for you, just know it worked the last time. Will see if I am lucky twice.
Chuck

[PrevostNewbie]

That's not how auto slack adjusters work, you might have a bad one.

[Ck2hans]

Mark:
Other than the passengers side dual my temps on all the wheels are similar to yours. Interesting how the tags run hotter than the rest.

[Fratto]

Thanks Chuck ... Its good to know.

[Coloradobus]

Have you checked your caliper piston boots for integrity and piston lubrication. If a piston is sticking, adjusting slack adjuster wont help. My 2 cents. Im assuming like our former 2000 Marathon H, you have disc all way around

[Ck2hans]

Jim:
I do have disc all around. Calipers were rebuilt about 2 yrs ago with new pads, coach is kept in a climate controlled garage so rust/rot of caliper pin/boots is unlikely although I do have that on the radar and will be checking it out. Biggest obstacle at this time is finding time to do it. Don’t have any trips planned anytime soon so it’s on the get around to it list right now.
Thanks for the thoughts/input