Tires, TPMS, blowouts, etc.

[DonTom]

In two days, I got two blowouts. Both on the right rear of my Y2K RV. I am now in Wesco, CA staying overnight at a tire shop.

The tires on this RV are the LT 225/75R16.

First, I have a question. If the tires are 75 PSI cold, what PSI would you expect on rear tires after 100 miles or so at 65-70 MPH?

I looked at my TPMS no more than ten seconds before today's blowout. That tire was near 100 PSI. The others were in the mid 80's. And what tire temp range is considered normal? I didn't look at that, as I wasn't expecting the blowout to happen in ten more seconds with no real warning, much like yesterday.

What could cause the temp to raise just before the blowout?

-Don- Wasco, CA (raining here).

 

[Mountain high]

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Check for brake dragging. The tire obviously overheated. The TPMS is attached to the wheel and it too was overheating. Fortunately, wheels usually don't blow to pieces, but tires do. The wheel may have overheated due to a brake issue. Replacing the tire isn't going to solve the root cause until everything it will be mounted to is inspected. You need to inspect all of the components down to the play in the axle bearings, brakes, wheel, etc.

 

[Krazeehorse33]

My guess is pressure hadn’t updated. It was low, increased drag, increase temp then catastrophic failure.

 

[DonTom]

Check for brake dragging.

Thanks, I never thought about brake drag. I will be sure that is checked. If something is overheating, it will explain a lot with my many flats on that side over the years.

From now on, I will make sure the rims are not getting extra hot on either side.

-Don- Wasco, CA

 

[NY_Dutch]

It could be brake drag, or could also be a failing wheel bearing. What do you have the high pressure alert set for?

 

[DonTom]

It could be brake drag, or could also be a failing wheel bearing. What do you have the high pressure alert set for?

My TPMS doesn't have a high PSI alarm. I need to read the PSI to see if it is high.

Now, I understand the purpose of the high temp alarm.

I had no idea such things as brake drag could cause a tire to overheat and cause a blowout, but it makes sense. Sure explains why I get so many blowouts on that side.

-Don- Wasco, CA

 

[NY_Dutch]

My TPMS doesn't have a high PSI alarm. I need to read the PSI to see if it is high.

Now, I understand the purpose of the high temp alarm.

I had no idea such things as brake drag could cause a tire to overheat and cause a blowout, but it makes sense. Sure explains why I get so many blowouts on that side.

-Don- Wasco, CA

Which TPMS do you have? I wouldn't use one without a settable high pressure alarm.

 

[DonTom]

Which TPMS do you have? I wouldn't use one without a settable high pressure alarm.

Some Chinese thing. But one thing I do like about it, is it will update every hour or so when NOT moving. Every few minutes while driving for most normal PSI changes, but a big change is instant. The no upper alarm for PSI isn't a big problem for me as I look at it often, I noticed it was high today just before the blowout.

However, I just thought about something that makes little sense. Only one wheel was reading high today. The wheel right next to it did NOT read higher than the other wheels. And that was the wheel that gave me trouble yesterday.

My rear wheels are drum brakes. I recall seeing the drum yesterday when I had both tires off. And I know drag is a rather common problem with drum brakes. I will be sure I have that checked in the morning. But these guys are difficult to communicate with, they are all Hispanic. But their English is a lot better than my Spanish!

A bunch of workers came in here tonight, so I got to meet them. I have no idea why they came here on a Sunday night, but I next four of them. Perhaps this is a family ran business.

-Don- Wasco, CA

 

[DonTom]

Again, what is the normal increase in PSI about for when 75 PSI cold after 100 miles at 70 MPH? What should be expected? Is a 15 PSI increase higher than normal? At times, I wonder if they are all high.

-Don-

 

[8Muddypaws]

the pressure increase is not directly related to how far or fast you've driven. It's related directly to how hot the wheel/tire is. Hot air expands, right?

The tire manufacturer is likely to have a website that shows maximum pressure and temp for all of their tires. Since your TPMS doesn't show temp you should be diligent in watching the pressure.

I had kind of the same experience. Crappy tires. In my case they were Goodyear Marathons....it was over 20 years ago And happened mid span on the Benecia Bridge. I replaced all of them ASAP It turned out that the replacements were also crappy and they started failing in only 3-4 years.

A better TPMS might be a good investment.

 

[DonTom]

Since your TPMS doesn't show temp you should be diligent in watching the pressure.

It does show tire temps , just has no high temp alarm. It's in smaller numbers that I am not in a habit of looking at--as I have no idea what they mean. I do see different temps for different tires while driving but I don't know what a normal range is for temps.

-Don- Wasco, CA

 

[DonTom]

I replaced all of them ASAP It turned out that the replacements were also crappy and they started failing in only 3-4 years.

That is the age of most of my rear tires, if not a year or so more. But I have new fronts, only a few months old.

Did you also get blowouts? Ever two of them in two days on the same side?

These days, what brands are considered good and bad tire brands?

But I probably have no choice at the tire shop I am now at.

-Don- Wasco, CA

 

[viceprice]

I would buy an infrared temp reader and use it to help diagnosis your heat source. Stop and check when you start to see abnormally high tire pressures or a difference between the pressures. It can be useful for a lot of heat related things. Harbor Freight has a couple to chose from $15-30. I use one to check brake (disk and drum), hubs, wheels, tires (sidewall and across the tread surface) on TV and TT as soon as I get out at a rest or fuel stop. I now have the 507 TPMS on the TT. It has similar sized tires on it as your RV (15 in diameter) I have seen 10-15 psi I ncreases in pressure. It has also shown a remarkable difference in tire temp between the left and right sides when travel direction sort of sets up so the sun is shining on one side more prominently than the other. I love the 507 TPMS.

 

[viceprice]

Manufacturer of the 507 is TST. If you search "507 TPMS" here, you will see other threads about this and other TPMSs.

 

[Laura & Charles]

From 75 psi cold, mid 80s hot isn’t unreasonable, near 100 is not, IMO. Sunny side of coach on a sunny day will be higher than shaded side on the outside dually.
I’ve been told you should replace duals in matched pairs when one needs replaced (and ideally, whole axles replaced together).

 

[Ray-IN]

The TST brand TPMS system models all have a high and low pressure alarm, it's in the owners manual how to set them.
The overwhelming majority of all tire failures are the result of underinflation/overloading.
Source: Do You Have Under-Inflated Tires? | Michelin

You'll note that even though Michelin has tire inflation charts, this Michelin website states to inflate to the door sticker/Federal Tire placard requirements.
Roger Marble is a retired tire design engineer, he goes by Tireman9 on RV websites. He owns and maintains RV Tire Safety .
He speaks at many tire seminars across the nation regularly, including discussing tire temperatures under various conditions.

 

[Mountain high]

 

[Mark_K5LXP]

Were you driving on the sidewalk again?

Mark B.
Albuquerque, NM

 

[Mountain high]

Were you driving on the sidewalk again?

Mark B.
Albuquerque, NM

Right rear tire clipping the curb. Not an uncommon thing with a RV.

 

[Larry N.]

My TPMS doesn't have a high PSI alarm. I need to read the PSI to see if it is high.

Now, I understand the purpose of the high temp alarm.

As a couple of folks mention above the TST 507 (love it) has the pressure alarms, temp readout, etc. But in addition, I routinely use an infrared gun to check the temperature of each tire (including the inside duals) and each hub, including the toad at every stop. It's the first thing I do once I'm parked, grab the gun, walk around checking each tire/hub as well as an overall check for any visible problem, including security of the tow bar, etc.

Note that it also warns you of tire temps at or above 158º, according to one web site, but on mine the high temp alarm is also programmable, in addition to the high/low pressure alarms.