Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 02-09-2016, 09:51 AM   #15
Senior Member
 
DMTTRANSPORT's Avatar
 
Join Date: May 2014
Location: Henderson, Nevada
Posts: 1,225
Quote:
Originally Posted by gnlandrus View Post
My question is, what would be considered a dangerously high pressure that would require me to pull over and deal with it ? Lets use a steer tire with a cold pressure set to 110 lbs. as an example. At what pressure should I take action, assuming all other conditions are normal.



Sent from my iPhone using iRV2 - RV Forum
This is an example of my statement, you are talking of a high AP which will happen in a normal case and in a low tire/leak/puncture case, are you going to pull over every time the pressure seems high?? bump the tires every evening and when fueling...
__________________

__________________
2005 Newmar DS 4023, Spartan Chassis, ISL 370 Cumapart, 2008 Jeep Rubicon 4dr, 2015 Kia Soul, 1969 Italian & 2004 Akita
DMTTRANSPORT is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 02-09-2016, 09:55 AM   #16
Senior Member
 
IASM's Avatar
 
Join Date: Nov 2013
Posts: 449
Greg-I don't think that's something under your control unless the tire is overloaded or running under inflated and building to much heat.
The manufacture is assuming temp and pressure increase in there charts. I would make sure the weights are known and cold pressure within guidelines.
Rod
__________________

__________________
IASM is offline   Reply With Quote
Old 02-09-2016, 10:41 AM   #17
Senior Member
 
britcon's Avatar
 
Join Date: Mar 2011
Posts: 578
Quote:
Originally Posted by DMTTRANSPORT View Post
This is why I do not own a TPMS, sure it will let you know if you have a tire going down/flat, but thats it, rolling down the road you will get unrealistic readings depending on the tire temp., OAT, ALT, etc.
To each his own. Personally, I want to know if my inside dual is going flat before it comes apart and rips the heck out of the wheel well. Cheap insurance IMHO.
__________________
2014 Newmar Ventana 4037 / 4018
2015 Jeep Grand Cherokee Ltd.
1940 Chevrolet Pickup
britcon is offline   Reply With Quote
Old 02-09-2016, 10:49 AM   #18
Senior Member
 
DMTTRANSPORT's Avatar
 
Join Date: May 2014
Location: Henderson, Nevada
Posts: 1,225
Quote:
Originally Posted by britcon View Post
To each his own. Personally, I want to know if my inside dual is going flat before it comes apart and rips the heck out of the wheel well. Cheap insurance IMHO.
Never needed one with 58 tires rollin and a heavy load, it's like the auto slack adjusters they also keep you from hands on issues....JMHO!
__________________
2005 Newmar DS 4023, Spartan Chassis, ISL 370 Cumapart, 2008 Jeep Rubicon 4dr, 2015 Kia Soul, 1969 Italian & 2004 Akita
DMTTRANSPORT is offline   Reply With Quote
Old 02-09-2016, 10:53 AM   #19
Senior Member
 
Join Date: Jul 2012
Location: North Lake Tahoe
Posts: 155
Tire pressures will vary with the temperature. For every ten degrees the pressure will change by a pound.
__________________
2016 Rockwood Signature Ulta Lite 8280WS
2004 Dodge 2500 4x4 crew cab long bed, 5.9 Cummins, 6 speed New Venture, Pac Brake
English Shepherd, Australian Shepherd, 5 year old puppies keeping us young
Greytraveler is offline   Reply With Quote
Old 02-09-2016, 10:55 AM   #20
Senior Member
 
Join Date: Feb 2006
Location: NW Arkansas
Posts: 116
Quote:
Originally Posted by DMTTRANSPORT View Post
This is why I do not own a TPMS, sure it will let you know if you have a tire going down/flat, but thats it, rolling down the road you will get unrealistic readings depending on the tire temp., OAT, ALT, etc.
After checking tire pressures before our most recent trip, I monitored the TPMS screen the entire trip. 155 miles from home a tire began losing 1 PSI every 10 miles. The pressure was within range when I stopped 90 miles later but, the next morning the tire was down to 15 PSI (Flat) and was taken in for repair.

TPMS works for some things.
__________________
JumboJet is offline   Reply With Quote
Old 02-09-2016, 02:38 PM   #21
Senior Member
 
Betr2Trvl's Avatar
 
Join Date: Dec 2014
Location: Georgia
Posts: 1,067
Setting the alarm levels on the TPMS does not have to be an exact science......

For low pressure, I set mine about 5#s below my minimum cold pressure settings.

For high pressures, set it initially about 20-25#s higher than your cold settings. Then simply see what you get across all the tires too after driving a while, then adjust your alarm setting from there. I have mine about 10#s higher than what I saw on hot tires on hot summer afternoons.

As noted, if I get a low pressure alarm after driving, I would have lost about 20#s of air pressure from the hot pressures at that point which would indicate a leak of some sort, which is what I (and I would think most people) are most concerned with. We usually check the monitor throughout the day when we are driving just to make sure all seems good. And I am really just as concerned with the toad pressures as I am the coach, since you have no feel if a toad tire is going down, or for instance, the parking brake is left engaged and you get a heat or high pressure warning from dragging a tire.....

Btw, on high pressure tires on a MH your pressure deviation is closer to 2#s per 10 degrees ambient while your car is about 1# per 10 degrees (rounding both to keep it simple). So the OP gained about 6-8#s just based on ambient temp.

The other thing to keep in mind is that you drive very little on cold tires, just a few miles before they heat up and you see the pressure gains which can vary quite a bit even from the same cold setting depending on sun, sun on one side or the other, rain, ambient temp changes, etc. Cold tire pressures are just that, cold minimum pressure settings. Even so, on my cars and MH, I'll set a bit higher in the fall if I set my tires when it is 70 degrees for instance and expect to drive in cooler temps where I'll loose a few pounds due to lower ambient temps.

Regards
__________________
D&S
2015 Tiffin Allegro 31SA; 24k chassis, Sumo springs
2015 Jeep Cherokee Trailhawk
Betr2Trvl is online now   Reply With Quote
Old 02-09-2016, 04:12 PM   #22
Senior Member
 
Selah's Avatar
 
Join Date: Oct 2012
Location: Indiana
Posts: 2,320
My TPMS cost a little over $300. Friend of mine saved $300 by not having one. Same friend had a flat on his toad that cost over $1800 to repair. Friend now has a $2100 TPMS.
__________________
Paul, Kathy, and Tux the Mini Schnauzer
2014 Tiffin Phaeton 42 LH, 2013 Honda CRV
"When the time comes to look back, make sure you'll like what you see"
Selah is offline   Reply With Quote
Old 02-09-2016, 07:40 PM   #23
Senior Member
 
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 1,731
When you first install a good TPMS, it's a good idea to just monitor what is happening as you drive. The OAT and heat from the rolling tire will increase the pressure and to some extent the temp readings. I don't pay much attention to the temp reading, because it is influenced both up and down by the OAT. For the first few trips don't be alarmed by what you see. After several trips, you will know what is normal for the tires on your motor home. This assumes that you started with the correct pressure in each position. Now, after seven years of experience with a TPMS, I know what is normal and when to be concerned. In that time, I have had a blown trailer tire at night. I had no idea it had blown except for the monitor alarm which showed me what position had lost pressure and that the other tire on that side was increasing in psi and temp at an alarming rate due to the added weight it had to carry. I stopped, changed the tire and was on my way. I can only imagine what the damage and cost would have been without my TPMS when the second tire failed. Needless to say, I'm a believer.
__________________
2013 43 QGP Allegro Bus
Crasher is online now   Reply With Quote
Old 02-10-2016, 09:34 AM   #24
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 18,099
Quote:
rolling down the road you will get unrealistic readings depending on the tire temp.
What's unrealistic about that? It is the actual pressure in the tire at that time.

Tire pressure increase about 2% for every 10 degrees of temperature change. If you set the pressure when the tire was at 20 F. ambient, and then drove it 20+ miles, the tire itself probably climbed to 90+ degrees. Maybe more under some conditions. On a warm day it is not unusual for a tire to hit 110+ degrees. That's an easy 15% increase, and 20-25% is not out of the question. Nor is that necessarily a problem, but it is worthwhile to be warned it is happening, in case the cause is something else, e.g. an overheated wheel bearing or a dragging brake.
__________________
Gary Brinck
Former owner of 2004 American Tradition
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC
Gary RVRoamer is online now   Reply With Quote
Old 02-10-2016, 09:54 PM   #25
Senior Member
 
Ray,IN's Avatar
 
Join Date: Aug 2001
Location: North America somewhere
Posts: 13,713
According to Goodyear:
"IMPORTANT: It's a common practice for RV owners to lower tire pressure in their search for a smoother ride. This is not only dangerous, it's relatively ineffective, as the difference in ride quality is not significant."

When you run the minimum air pressure for your load instead of mfgrs tire placard, you make your MH more susceptible to sway from wind, passing large vehicles, and sudden maneuvers.
As to how high pressure must get to be dangerous, Tireman9 is IMO the best person to actually know. If I remember correctly, he was a tire design engineer when working.
__________________
2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member,FMCA."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert the Constitution. "Abraham Lincoln"
Ray,IN is offline   Reply With Quote
Old 02-11-2016, 09:20 AM   #26
Senior Member
 
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 1,731
Quote:
Originally Posted by Ray,IN View Post
According to Goodyear:
"IMPORTANT: It's a common practice for RV owners to lower tire pressure in their search for a smoother ride. This is not only dangerous, it's relatively ineffective, as the difference in ride quality is not significant."

When you run the minimum air pressure for your load instead of mfgrs tire placard, you make your MH more susceptible to sway from wind, passing large vehicles, and sudden maneuvers.
As to how high pressure must get to be dangerous, Tireman9 is IMO the best person to actually know. If I remember correctly, he was a tire design engineer when working.
So who's recommendation do we follow, the Motor home manufacturer who must cover any liability of some owners irresponsible loading and assumes maximum weight or the tire manufacturers load chart that through testing has determined the correct pressure for any given load? The load chart may give the minimum pressure, but it is also the correct pressure. I had an Avalanche that the placard said 35 psi in the tires. Depending on the load, I carried as low as 26 psi using the load chart. At 80,000 miles the tread wear was even and still safe to drive. The load chart recommendations work, but require an operator that is diligent in following it.
__________________
2013 43 QGP Allegro Bus
Crasher is online now   Reply With Quote
Old 02-11-2016, 10:15 PM   #27
Senior Member
 
Ray,IN's Avatar
 
Join Date: Aug 2001
Location: North America somewhere
Posts: 13,713
Crasher, follow the MH tire placard air pressure, tire mfgrs do not know how their tires will be used, that is beyond their control.According to the RMA/Rubber Manufacturers Association, over 90% of all tire failures are due to underinflation/overloading.

Back to the original question; bursting pressure of MH/truck tires. This 1983 study from U of Michigan says a radial truck tire will burst somewhere around 341 PSI. This is also enough pressure to deform the bead surface of a one-piece truck rim, making is unusable.
That said, the sidewall listed air pressure is self-explanatory, but tire mfgrs.also say 10-15 PSI over that is still safe.
__________________
2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member,FMCA."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert the Constitution. "Abraham Lincoln"
Ray,IN is offline   Reply With Quote
Old 02-11-2016, 10:31 PM   #28
Senior Member
 
Mr_D's Avatar
 
Solo Rvers Club
iRV2 No Limits Club
Join Date: May 2011
Location: Vancouver, WA
Posts: 28,535
Quote:
Originally Posted by Ray,IN View Post
That said, the sidewall listed air pressure is self-explanatory, but tire mfgrs.also say 10-15 PSI over that is still safe.
If that was true then why does it keep coming up time after time?
__________________

__________________
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '14 CR-V
Mr_D is offline   Reply With Quote
Reply

Tags
tire pressure



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Weighed RV, how do I use this data to determine tire pressure? terryl Class A Motorhome Discussions 28 09-06-2015 07:49 AM
One more tire pressure question...sorry Jim28730 Class A Motorhome Discussions 8 07-22-2015 03:54 AM
Tire pressure deviation WDW MH-General Discussions & Problems 48 05-07-2015 07:54 PM
Checking Tire Air Pressure - E450 s1njin Winnebago Industries Owner's Forum 10 04-24-2014 07:13 PM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:34 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.