Tire Pressure - Montana Owners Club

BandJ · 04-24-2006, 01:05 AM

Do you lower your air pressure in the REAR tires when not towing. If so how much and why. My tires call for maximum pressure of 80 psi.

Montana_2005 · 04-24-2006, 02:07 AM

We usually keep ours between 75 and 80 winter and summer... "correct" tire pressure supposedly helping a fair percentage on MPG's to say nothing of handling on rough roads and wear and tear on the tire.

Fordzilla · 04-24-2006, 05:37 AM

I always ran my SRW p-up's at 80 all summer long and dropped it down to 55 in the front and 45 in the rear during the winter when the trailer is in storage. The lower pressure does wonders when driving on ice and snow. I normally air them up right before going to pick up the trailer in the spring and leave them @ 80 until done towing.
Now with the DRW the door jam sticker says only 60 for the back duals and 75 for the fronts. I was a little skeptical and tried it on a short journey over the weekend and checked to see if they were getting warmer at every stop. They performed great on that trip, but I think I may pump them all up to 80 like the tire manufacturer suggests before any long trips.

firetrucker · 04-24-2006, 09:01 AM

Ron,

Before you pump up your tires to the maximum pressure, double check with the maufacturer. That pressure on the sidewall of the tire is for the maximum load only. The pressure you use should be based on the actual load the tires carry. Many manufacturers have a table of pressure versus load on their websites. After the Firestone/Ford debacle, car manufacturers have been very careful to identify the proper pressure on that sticker on the door frame.

Bob

Illini Trekker · 04-24-2006, 10:56 AM

GMC door plate says 55 front 80 rear, I run 55 front and 60 rear with out a load.

Montana Sky · 04-24-2006, 11:39 AM

I run 80 psi on the front and rear of the truck when towing. When not towing I drop them down to 55 psi (cold) to soften the ride and also allow the tires to wear flat. If you tend to leave high air pressure in them when not putting a load on, the tires will wear funny in the center of the tread pattern. The same is true if you under inflate them, they will wear funny on the outside of the tread pattern. I did this on my factory tires on this truck and got 36,000 miles with even tread wear. Replaced those with the current tires back in October and have 16,000 miles on these already. So far they are wearing very well. As far as the coach, it stays at 80 psi all year.

Gene Chaltry · 04-24-2006, 03:06 PM

I run 65 in front, 80 pounds in rear all the time. No problems.

Mac · 04-24-2006, 03:44 PM

I'm a 75-80 pounds towing and 55 all around in the winter when not towing.

mac

fulltimedreamer · 04-24-2006, 04:14 PM

I run 55 front and 70 rear all the time. My first set of tires were replaced at 61,000 or so. I kept them rotated and was very pleased with the even wear. The replacement set have 22,000 or so on them and seem to be wearing very well too. This is with pulling my TT with a weight of 10,000 lbs and a tongue weight of 1000 lbs.

patodonn · 04-24-2006, 06:12 PM

We run 55 front and 80 rear while towing, and drop the rear to 55-60 if not towing for a week or more. Also drop the air bag pressures from 40 psi (towing) to 10 psi when not towing for a week or more.

It should be noted that there is no more weight on the front tires when towing or not towing..they should be at mfg specs for your truck, which is about 55-60...just a thought/

richfaa · 04-25-2006, 05:09 AM

Just returned from a morning with our Tire guy, Long time friend, Fellow Lion member . Tires all our Vehicles and purchased our Terry TT in September 05. First..Ford does dumb things also..We noted that the valve stems on both the inside and outside dually lined up with the same hole in the rim making it very difficult to check the air pressure or add air.. He pulled the outside dually, rotated it 180, put a bendey valve stem on the inside dual wheel and the problem is solved.. On tire pressure.Saw no need to vary the tire pressure in the TV except for personal preference,80 psi cold means just that, it may ride rough but will not harm the tires.. reminding me that HEAT is the PRIME destroyer of tires. On balancing the camper tires,,it is a good idea..a badly out of balance tire will contribute to heat buildup and increased tire wear. They will ALWAYS balance the tires on a Camper or boat trailer when new tires are purchased.Mission tires are no better no worse that any OEM tire any Brand any country of manufacturer. So we will keep 80psi in both the camper and TV..we will buy better tires and have them balanced before we hit the road for Texas and Arz this winter.Oh--he did not charge me for the tire rotate, he bought BKFST BUT he will call when he they are ready to de winterized their, our previous , camper for proper instructions...The Barter system is alive and well in Ohio...

Fordzilla · 04-25-2006, 06:07 AM

Rich, I noticed the same problem with the rear dual valve stems lining up in the same hole. I ended up having to go out and buy a different tire gauge that has an angled head to reach the back ones. I think the first time I have them rotated I am going to have them spun 90 degrees each rotation to keep them from getting any flat spots on the same spot on the both tires. And I will be adding extensions if I can find some that work. One of my summer purchases is hopefully going to be a tire pressure monitoring system. Then hopefully I won't have to check them too often.

richfaa · 04-25-2006, 07:02 AM

My tire guy said that the rubber/vinyl valve extensions are prone to leaking and he sees that quite a bit with Rv's at the shop. I have not yet been able to find a metal/mesh extension that will fit as the ones I have seen are made for the larger truck duallies and are to long or the clamps to hold them to the rim will not fit on the Ford rims as they are(the rims) to thick. It looks like rotating the wheel 90 or 180 will make checking and adding air doable. We also have one of those long angled head tire gauges that we picked up at a truck stop and it helps.. Tne more I think about the tire pressure monitoring system the better it sounds...

Fordzilla · 04-25-2006, 10:20 AM

cheapest I have seen is $690 for a Doran one which will monitor 10 tires. I have to weigh it out before I will spend that kind of money. But we had three blowouts with the past trailer and checked the tires before and during every trip. So really one repair job would offset the price of the monitoring system. I really have myself talked into it already, it's just that I would like to shop around an see if I can find a better price.

Montana Sky · 04-25-2006, 10:32 AM

I thought about buying a tire pressure monitor system for the truck and coach. I decided without it I have another reason to pull off during the day, stretch the legs and check the pressure and temps on the tires. So far it has worked well for me and saved me a bunch of money.

richfaa · 04-25-2006, 12:51 PM

There are a lot of vendors at the FCRV campvention and I think that last year I saw the Doran system for less than that. I am also going to get a 50 amp autoformer there .There was a vendor there last year with some very good pricing. The autoformer is a must for us now..am still thinking on the tire monitor. We will not be driving the bus any more so our goodie money is restricted.

sreigle · 05-08-2006, 09:24 AM

Make sure the Doran will really work for you. I bought that system for $500 for 8 tires back in 2002. I found the signal would not usually reach from the right rear trailer wheel to the unit under the dash. Sometimes it worked. Doran sent me an antenna extension that I mounted by the rear axle. That helped a little but didn't solve the problem. Doran replaced a couple of the units but they did the same thing.

The units on the valve stems ate batteries. Like once per month. Each unit took two button batteries available at Walmart. About 3.50 per pair if I recall. Also, before fulltiming, the Montana was not close enough to the truck to trigger the alarm. If a tire on the Montana went 5 psi low, the unit on the valve stem would just continue sending out a signal and the battery would run down in a couple of days. When I hitched up again I had no way of knowing those batteries were dead. Maybe the newer units are better than the one I had.

If I were going with tire monitors again I would go with the kind that strap to the inside of the rim. Just my opinion based on a $500 mistake.

Fordzilla · 05-08-2006, 09:35 PM

That's good info to have Steve. I looked at those when they were in Trailer Life magazine a few months ago. Looked real nice, and no worry about loosing the caps. I will have to drum around on the net and see what everyone is saying about them before I spend that kind of $$.

Wrenchtraveller · 05-09-2006, 02:40 AM

Lots of good advice here and for sure more tire problems are caused by low pressure than are caused by high pressure.
I always run my fronts at 70 and my rears at 80 and have never had a problem. In fact back when I had a 95 F250 with 8800 GVWR and all loaded up with the slide in Camper, I was over 11000 pounds so I ran 90 PSI in the back because I had reliable information from a tire maker that if you do go over your tire's weigh capacity , then you should add 10 pounds over your tire's max rating.
For years people ran around with big Lance 11' campers on Ford F250s and these were all overloaded to the extreme and that is when they were telling people to run 90 psi in their tires. I know quite a few people other than myself that ran 90psi and never had a problem.

steves · 05-09-2006, 07:37 AM

This an extract from the documentation I got from RVSEF when they weighed my 3400.

"The tire and Rim Association standards permit increasing the pressure of Light Truck (LT) tires up to 10 psi over that shown on the sidewall, and up to 20 psi for truck tires". "This DOES NOT increase the rating of the tire, but helps it to run cooler".

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