New Tires and Pressure - RV-Dreams Community Forum

leno · RV-Dreams Family Member

New Tires and Pressure

Jack Mayer · RV-Dreams Family Member

The ONLY way to know what pressure you need is to know the weight of the trailer. Then set the tire pressure based on that weight - the tire manufacturer will have a weight chart on their website, or you can use a universal one for that tire size and rating.

If you do not know the weight then you have to assume it is maxed out for that tire size and run the full pressure.

Unless that tire tech knows your weights he is simply "guessing". Anyone that would do this clearly does not know what they are talking about. That's the way it is - anyone that tells you differently is incorrect.

flyone · RV-Dreams Family Member

I would suggest assume you have close to the weight limit and run the tires at full rated pressure. That way you have nothing to worry about if you have to travel with a little extra weight for what ever reason. Like Jack said the less air pressure in your tire the less weight it can safely carry, you over load it and you are taking a chance on it flying apart when you are rolling down the road. Why even chance it?

Flyone

RVDude · RV-Dreams Family Member

jack and fly have it to the tee. I must emphasize, there are no if ands or buts about what they have said. The ONLY rule of thumb in setting TP is if you don't KNOW the weight on each individual tire and look up the TP on the tire MANUFACTURERS charts then you HAVE to assume worst case and fill to the max load capacity for that tire which is the max stated on the sidewall and hope the tire has the proper capacity for its use. I must repeat, there are NO exceptions.

Terry and Jo · RV-Dreams Family Member

I used to drive semi-truck/trailer rigs weighing up to (and occasionally a bit over) 80,000 pounds for the whole rig and its load. While there may be a wee bit of truth that tires slightly underflated will give one and one's trailer a "smoother" ride due to the additional flex in the tires, we NEVER ran tires under the tire manufacturer's ratings.

To do so would have caused all underpressure tires to flex more and thus overheat the rubber, leading to the real possibility of blowouts. And no one wants to experience blowouts if they can help it. Not only do they ruin tires, they also cause damage to the vehicle on which they are mounted.

The only time I have known of people deliberately underinflating is when they are involved with the off-roading sport.

Terry

Jack Mayer · RV-Dreams Family Member

Underinflated is underinflated.....there is NO circumstance in which you drive underinflated on the road.

Just as a point of interest, we offroad extensively. I'll drop the pressure on my tires to 12-14psi (what you decrease to depends on the tire size and type). However, that is not underinflated for the tire I run and the speeds we travel.

Speedhitch · RV-Dreams Family Member

I was told if the tire is inflated to its max and the load is not there the tire will wear in the middle. The tire at the max should have the load on it to wear correctly. Maybe I misunderstood what was said. Please clearify this if you can.

Speedy

leno · RV-Dreams Family Member

Thanks everyone for the reply. We are going back to tell them they don't know what they are talking about and have them fill to max load. Really appreciate the help.

RVDude · RV-Dreams Family Member

Sir Speedy is spot on, again. Proper inflation is tied directly to weight. No two ways about it. In the absences of knowing the weight you MUST assume the worst case. A little possible center wear sure beats a blown tire due to under inflation.

Jack Mayer · RV-Dreams Family Member

Why would you go back to a tire dealer to inflate your tires? Don't you have a tire pump? If not, you should.

Hook up your trailer and run through a truck scale. It won't tell you individual wheel weights, but it will tell you a lot about your rig.

leno · RV-Dreams Family Member

Thanks Jack. No we don't have a tire pump but will look into getting one. Also, the tire dealer is easier and closer to us than any other place to fill the tires. I also wanted to let them know they gave us bad information. Hubby did that today and we are ready to head to Kerrville tomorrow..

mailman01 · RV-Dreams Family Member

Question concerning tire valve stems: I have 16" rims, steel, I believe, with 80 lbs of pressure max recommended. The stem appears to be metal with black rubber near the rim entry point. When I put a slight amount of pressure on the stem pushing it in any direction air escapes from around the base of the stem....this will happen on any of the four tires. This is a new camper (Arctic Fox) and I have not brought this issue to the attention of the dealer, yet. Before doing so, I wanted some other experienced opinions to help me be better armed when approaching the dealer concerning this, just in case he may tell me "this is normal." If this is in fact, normal, I feel confident the wise and experienced readers of this will verify this...Thanks a lot....Marty

Judy · RV-Dreams Family Member

Have you tried tighting the nut on the valve stem?
southwestjudy

Luvglass · RV-Dreams Family Member

Definitely not normal. If it's a new rig, I'd take it back to the dealer for correction.

-- Edited by Luvglass on Monday 13th of April 2009 07:23:31 AM

mailman01 · RV-Dreams Family Member

Thanks folks for the advise, I did speak to the dealer this morning and he was very receptive to the situation. He also said this was not a normal and that the stems were apparently not properly seated at the rim and that I should take it to a nearby tire shop, have it repaired/stems replaced, or whatever is needed and to send him the bill. Can't beat that. Sort of surprised this occurred on a new unit. Thanks again, Marty

RVDude · RV-Dreams Family Member

I'll guess Judy has the right answer - about a 10 min total job all around - unless the tires need to be dismounted. Just some info for your dealings at the tire shop - regardless of who ultimately ends up paying.

mailman01 · RV-Dreams Family Member

There are no nuts on the valve stems, simply inserted from inside the rim. Northwood put me in contact with the manufacturer in Idaho for a resolution. Apparently these should have been steel stems with the nut on the outside to securely tighten things down, but they were not. Folks with Arctic Fox/Nash products may want to check their valve stems...Marty

RVDude · RV-Dreams Family Member

Here's a potential recall that might affect your (and 6,000,000 other) stems.
Official NHTSA valve stem recall

The following yellow box is a simple summary of the NHTSA recall provided by www.aa1car.com

WARNING: DEFECTIVE MADE-IN-CHINA TIRE VALVE STEMS RECALLED

Cheap Rubber Valve Stems Are Cracking and Failing, Causing Tire Blowouts & Rollover Accidents

cracks in tire valve stem

A recall notice affecting as many as six million Chinese-made automotive tire valve stems has been issued as of May 30, 2008. The defective tire valve stems were made in China by Shanghai Baolong Industries, and were distributed in the United States to many independent tire dealers by Tech International of Johnstown, Ohio. The defective valve stems were manufactured from July 2006 to November 2006, and were installed on vehicles in the U.S. from January 2007 to July 2007 (or possibly later).

Motorists who have had tires replaced or serviced in 2007 are warned to inspect their valve stems for cracks or leakage.

Examine the valve stem and flex it in a circular motion with your finger. If you see any visible cracks or hear air hissing (leaking) from the base of the valve stem, the valve stem is defective an must be replaced. Failure to replace the valve stem may cause the tire to lose air or suddenly go flat. Sudden loss of air pressure at highway speeds can be very dangerous, and may cause the driver to lose control and have an accident or rollover!).

There are no external markings on the valve stems to identify their source, so the only way to know if the valve stems on your vehicle are those involved in the recall is to have your tires dismounted so the numbers on the bottom of the valve stem inside the wheel can be read. The part numbers affected by the recall are:
TR-413
TR-413CH
TR-414
TR-415
TR-418
TR-423

For complete details about the NHTSA safety recall, Click Here. NHTSA CAMPAIGN ID Number: 08T018000

The above yellow box is from www.aa1car.com

A true metal stem uses a nut and a black rubber washer to attach them.

Apparently yours are standard rubber snap in style - some have metallic sleeves around the stem. These are potentially the ones in the 6 million unit recall above.

-- Edited by RVDude on Tuesday 14th of April 2009 01:07:06 PM

mailman01 · RV-Dreams Family Member

Dude, thanks for the info, mine are more like the black rubber ones and probably on the recall list you enclosed. I am having them replaced with the steel stems. Thanks again. Marty

Janeen · RV-Dreams Family Member

We are getting ready to take our new 5ver camping. We took it to the dealer for a minor repair and on the way home the rig was bucking all over the place. All I could do was keep in the slow lane and pray we made the 8 miles to home. We did and the first thing I remembered is somewhere on this site I read that bucking is mainly due to tire inflation errors. We checked the truck, tire one was 85psi, tire two was 74psi, tires on the rear ranged from 65 to 87psi! Holy crow batman! Then we checked the rig, 40 to 46psi all around. We're lucky we didn't have a catastrophy. Now we just bought new tires on the truck a month ago and the rig is a month old. The guy at the tire store said he put 80psi in the rear duallys and 65 in the front. The RV place said they checked pressure when they did the 'delivery'.

Word to the wise, don't ever take someones word for it when it comes to tire pressure. Check them yourself, it pays to be a control freak! :)