Front Tire Blowout

[twinboat]

Since I can only find one reference of flooring it with a tire blow out, and more saying let off the throttle and steer, like driver training manuals, I wouldn't floor it.

Besides, between reaction time and turbo lag or transmission downshifting, by the time you floor it, whats going to happen has already happened.

[Tireman9]

I'm not going to join the part of the discussion on what to do if a front fails. I would prefer that people did more to lower the chance of having a fron fail in the first place.


The original tire appeaars to have suffered a "Zipper" failure which is what a steel body tire can get after miles of operation with less air than needed to support the actual load.


Sometimes this is due to a puncture and air leak. Sometimes due to leaking valve. Sometimes due to intentionally running lower pressure in an effort to get a better ride.
No matter the reason if you can avoid operating with low inflation you can eliminate the sudden Zipper failure which comes from fatiguing the steel in the tire sidewall.


I don't know what load was on the tire or the inflation or if the tire was previously run when low on air. I also don't know if the TPMS was malfunctioning or had the low pressure warning set too low, but I suggest the low pressure warning be no lower than the minimum amount of air needed to support the measured load on the tire. I do not see how you can get a Zipper failure if you had at least the pressure needed to support the load. Zippers only occur when the tire is run when low on air.

[TonyMac]

Originally Posted by Tireman9

Zippers only occur when the tire is run when low on air.

TireMan, I'm always glad to see you weigh in on these discussions. Please define low on air. How low? Is just a couple of pounds gonna make any big difference? I air to placard limits with 95 in the rear and 110 up front, and I'll adjust in the morning when they get to 3psi off cold. My 4-corner scale weights were well under the tire weight limits and a bit under the axel weight limits.

[ptw]

Originally Posted by Tireman9

I'm not going to join the part of the discussion on what to do if a front fails. I would prefer that people did more to lower the chance of having a fron fail in the first place.


The original tire appeaars to have suffered a "Zipper" failure which is what a steel body tire can get after miles of operation with less air than needed to support the actual load.


Sometimes this is due to a puncture and air leak. Sometimes due to leaking valve. Sometimes due to intentionally running lower pressure in an effort to get a better ride.
No matter the reason if you can avoid operating with low inflation you can eliminate the sudden Zipper failure which comes from fatiguing the steel in the tire sidewall.


I don't know what load was on the tire or the inflation or if the tire was previously run when low on air. I also don't know if the TPMS was malfunctioning or had the low pressure warning set too low, but I suggest the low pressure warning be no lower than the minimum amount of air needed to support the measured load on the tire. I do not see how you can get a Zipper failure if you had at least the pressure needed to support the load. Zippers only occur when the tire is run when low on air.

I had the coach weighed three times, all wheels. The last time was the fall of 2018. I run the tires at 5 lbs over the recommended pressure on the Michelin chart. We should have less weight in the coach now because the first two years owning the coach we were RVing full time. I have been using a TPMS for 4 years. I don't recall what the low pressure is set at on the TPMS, it was set at the RV show when I bought it. I am currently not near the coach. The coach sat for 4 months so I checked the pressure before leaving with a tire gauge. The blowout occurred on the second day of driving after about 550 miles. The pressure was good the second morning. I didn't notice the tire pressure before it failed, traffic was heavy.

[knight13]

If you have a blowout, especially a new driver, it will happen so fast will you be able to think that fast?

[Cloud Dancer]

Originally Posted by knight13

If you have a blowout, especially a new driver, it will happen so fast will you be able to think that fast?

*
Short answer,....NO!
It's NOT just "think". it's think, process, execute. The trick is to have the process in your cerebellum (not your brain). That way it's like riding a bicycle,....you never forget how. All you do is execute.
There's only one most important thing you must do when you experience a front tire blowout in your motorhome. When the blowout occurs on a front steer tire, you only feel 2 sensations with your hand/hands. One sensation is the vibration, and the other is the feeling that something is trying to steer YOUR motorhome to the side of the blowout. YOU already know what you must do! It's the same thing you do when only one front tire hits a long puddle of water. Yes, something tries to steer your vehicle, and you instantly steer away from the puddle. And, you do it without thinking about it. You react instantly, AND with authority.

[Tireman9]

Originally Posted by TonyMac

TireMan, I'm always glad to see you weigh in on these discussions. Please define low on air. How low? Is just a couple of pounds gonna make any big difference? I air to placard limits with 95 in the rear and 110 up front, and I'll adjust in the morning when they get to 3psi off cold. My 4-corner scale weights were well under the tire weight limits and a bit under the axel weight limits.

I would think that 30% low could start some structural damage.


This does not mean that after driving 1/4 mile 30% low the tire is going to explode.

How many times can you bend a paper clip back and forth before it breaks?


Metal fatigue is not a 0% or 100% thing. You can do damage with maybe -20% but it might take many hundreds of miles. You might also fail the sidewall in just a few miles when almost completely flat. The load you are putting on the tire will also affect the steel bending so my ref to the % low also depends on the load.



A change in inflation of a few psi is not going to be significant in every day use.

[Tireman9]

Originally Posted by ptw

I had the coach weighed three times, all wheels. The last time was the fall of 2018. I run the tires at 5 lbs over the recommended pressure on the Michelin chart. We should have less weight in the coach now because the first two years owning the coach we were RVing full time. I have been using a TPMS for 4 years. I don't recall what the low pressure is set at on the TPMS, it was set at the RV show when I bought it. I am currently not near the coach. The coach sat for 4 months so I checked the pressure before leaving with a tire gauge. The blowout occurred on the second day of driving after about 550 miles. The pressure was good the second morning. I didn't notice the tire pressure before it failed, traffic was heavy.

I have covered how I set my TPMS on my blog RVTireSafety.net It is entirely possible the low pressure warning level is/was too low and you did not get an early warning before failure.


I have suggested, also in my blog, that people run a test of the TPMS annually. Everything made can fail to work properly.


When you get back to the coach you might check the settings before driving and check that the sensors warn as soon as you are at the minimum needed to support the load.

[Cloud Dancer]

Originally Posted by Cloud Dancer

*
Short answer,....NO!
It's NOT just "think". it's think, process, execute. The trick is to have the process in your cerebellum (not your brain). That way it's like riding a bicycle,....you never forget how. All you do is execute.
There's only one most important thing you must do when you experience a front tire blowout in your motorhome. When the blowout occurs on a front steer tire, you only feel 2 sensations with your hand/hands. One sensation is the vibration, and the other is the feeling that something is trying to steer YOUR motorhome to the side of the blowout. YOU already know what you must do! It's the same thing you do when only one front tire hits a long puddle of water. Yes, something tries to steer your vehicle, and you instantly steer away from the puddle. And, you do it without thinking about it. You react instantly, AND with authority.

*
The way to train your cerebellum for the above is easy. The next time and the next and the next time you drive a motor vehicle, every 3 miles or so just ask yourself: TODAY is the day a front tire will blowout, what is the FIRST thing I'll do? AND, answer yourself by saying INSTANTLY GRAB and TURN the steering wheel 2 degrees or whatever amount it takes to STAY in my lane!!!

[Johnynorthla]

I don’t know about everyone else, but I’m always glancing at my TPMS. I check it against a digital and analog gauge before every trip after my RV has been sitting for more than a week. I don’t rely on the alarm, plus I’m always interested in my tire temps. It amazes me how my RR, inside dully, rises in temp and psi as soon as I start driving, due to the placement of my exhaust being within 12” from it!

Heck, I’m glancing at all my gauges, (braking system, OBD2 gauge, RPM, speed, temps, etc..,etc..), constantly, like a good pilot should! I don’t do it out of fear, I do it out of process and a strong desire to make my trips safer and better for me and the family. I feel it’s part of driving a big rig!

[Tireman9]

Originally Posted by Johnynorthla

I don’t know about everyone else, but I’m always glancing at my TPMS. I check it against a digital and analog gauge before every trip after my RV has been sitting for more than a week. I don’t rely on the alarm, plus I’m always interested in my tire temps. It amazes me how my RR, inside dully, rises in temp and psi as soon as I start driving, due to the placement of my exhaust being within 12” from it!

Heck, I’m glancing at all my gauges, (braking system, OBD2 gauge, RPM, speed, temps, etc..,etc..), constantly, like a good pilot should! I don’t do it out of fear, I do it out of process and a strong desire to make my trips safer and better for me and the family. I feel it’s part of driving a big rig!

In my racing days when con fronted with a high exhaust heat situation I found that a short sheet of stainless set about 1" or more from the exhaust pipe would drop the temperature significantly. The exhaust wrap material didn't allow cooling air to flow between the exhaust pipe and the shield.


I also monitor the gauges and check mirrors almost constantly so I know where the other vehicles are and if there are any changes in vehicle operation.

[Cloud Dancer]

Originally Posted by Johnynorthla

I don’t know about everyone else, but I’m always glancing at my TPMS. I check it against a digital and analog gauge before every trip after my RV has been sitting for more than a week. I don’t rely on the alarm, plus I’m always interested in my tire temps. It amazes me how my RR, inside dully, rises in temp and psi as soon as I start driving, due to the placement of my exhaust being within 12” from it!

Heck, I’m glancing at all my gauges, (braking system, OBD2 gauge, RPM, speed, temps, etc..,etc..), constantly, like a good pilot should! I don’t do it out of fear, I do it out of process and a strong desire to make my trips safer and better for me and the family. I feel it’s part of driving a big rig!

*
Just a reminder: I trust that "...etc, etc." includes a frequent scan of all rear and side view devices. Positional awareness at the time of a tire blowout can be very helpful.

[knight13]

When my wife had a blowout, I also had a TM system, all we heard was a peep and the tire blow.

[WILDEBILL308]

I would look at how Michelin recommends how to handle a blow out.
https://www.michelinrvtires.com/tire...ce-and-safety/
Bill