# Tire Pressure



## j1mfrog (Jun 6, 2004)

Correct tire pressure in the Trailer and Tow Vehicle is very important and should be checked often. The problem is, I'm lazy, soooooo....

Anyone use these valve cap monitors?

http://www.jcwhitney.com/webapp/wcs/stores...1&storeId=10101

Are they worth it? Are they accurate?

It would make checking pressure a simple glance at the valve cap and that part sounds good to me.


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## mjwencl (Feb 25, 2004)

I just use the AccuTire Pressure Guage. Very accurate and temperature compensated. I keep it in its case in my Chevy Truck.

I'd be concerned about the valve stem units long term reliability without knowing more about them.


























MS-4000
Digital Tire Gauge with Backlit Display 
5-99 PSI in .5 LB Resolution 
Carrying Case


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## JimMcCombe (Apr 3, 2004)

Whatever you use, I suggest you use two different forms. I burned through a set of tires on our previous trailers because the "high end" pressure gauge I bought was off by 5 lbs. Didn't make a difference on our car/truck so much, but tire pressure on the trailers is a lot more sensitive. I currently use a digital gauge, and the old style manual "pen" gauge.

I don't have any experience with the valve cap monitors. They look neat though!


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## NDJollyMon (Aug 22, 2003)

I use a digital gauge as well. I keep tabs on it's accuracy with the old style gauge too.


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## campingtom170 (Apr 26, 2004)

As you all know, tire pressure is one of the critical factors for a safe and stable tow. I check the pressure in all tires everytime before I tow. I check when the tires are cold. At home, I use a portable 110v compressor, on the road, I use a 12v cordless. The tire gauge I use is an Ashcroft, 436-06, liquid filled gauge.

Several years ago, I was a crew member on a Pro-Mod drag car team. This is the same type of gauge that was being used then and is still being used by many NHRA and NASCAR teams today. I have found mine to be very accurate and durable.

I do still carry the stick type of gauge for the quick check and to verify the Ashcroft.

I guess I am still just a little too old school, translate fuddy-duddy, to go for the digital type of gauge







.

Tom sunny


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## kimacobb (Apr 4, 2004)

what is the tire pressure you are all running at?

mjwencl, where do you get such a handy tire gauge?

Kim


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## jgerni (Nov 10, 2003)

I run the max of 50psi or close to it in the trailer, the MAX on the TV rear and usually the max -5psi on the TV front.


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## hurricaneplumber (Apr 12, 2004)

Some tire pressure information I have found that is interesting to read:

"Note: Air pressure is what carries the load on every vehicle. For a tire to obtain it's full potential in safety, wear and mileage, the air pressure must be maintained in relation to the tire and the load it is carrying. To obtain the correct pressure, first determine the tire load then consult the tire manufacturer's inflation table. Never exceed the wheel manufacturer's maximum pressure!"

"The amount of air pressure in a tire determines the load that can be carried safely. Every Truck Tire will have the maximum load and inflation molded into the sidewall of the tire. This load and inflation ratio should never be exceeded since this can cause handling problems, irregular wear, and component failure. The proper amount of air pressure is always determined by the weight of your RV fully loaded. This weight takes into account all liquids, supplies, and passengers. Tires on RV applications are subject to a variety of more severe conditions when compared to automobiles or trucks. Because of many chassis and optional equipment differences, it is possible for an RV to be within its Gross Vehicle Weight Rating (GVWR), but overloaded when taking into consideration the weight of each wheel position. The only way by which you can know the safe load and inflation pressure for your RV is to know the actual weight of each wheel position under actual loaded conditions. Underinflation of a tire can cause poor handling, irregular wear, and decreased fuel economy. It also causes extreme heat build up within the components of the tire, which can lead to failure. Overinflation of the tire causes a deformation of the contact patch resulting in crowning of the center tread. This causes handling problems such as reduced traction, irregular wear, and an increased chance for impact damage.

Always check air pressure with an accurate air gauge at a cold PSI. Never reduce pressure when a tire is hot and never exceed the maximum cold pressure molded on the sidewall."


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## mjwencl (Feb 25, 2004)

I run the manufacturer recommended pressure of 50psi in each tire of my 2004 25RSS.

I purchased my digital tire guage from Amazon.com

I do verify with a manual NAPA quality pen guage. Very accurate readings with the digital. Accuracy I'd say to within 0.5 psi.

Cheers! It's Friday!


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## fixjet (Jan 19, 2004)

Jim, we use the tire pressure gauges on the valve stem on all our Heavy Jet Aircraft and they work very well. Seldom find one not accurate, but I'm sure they are of better quality than ones made for automotive applications. One thing is they are very heavy and you should balance the tires after installation. I check tire pressures on 18-36 tires a night so it's a great time saver when you have a high volume of tires to check. 
Dan


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## j1mfrog (Jun 6, 2004)

Thanks Dan

I think I'm going to try them out. I'll be sure to check their accuracy every now and then. It just so happens I need new tires so I can have the new ones balanced with these on.


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## NDJollyMon (Aug 22, 2003)

Hurricane...
Interesting article.
That would be great in a perfect world...weighing the unit each time I go camping. Not practical for me, so I run 50 psi. I also keep a close eye on them at gas/other stops while traveling. So far, so good.


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## hatcityhosehauler (Feb 13, 2004)

I learned, almost the hard way to check the pressure's *BEFORE* leaving for the trip. Last weekend, my father and I went down to Wildwood State Park in Long Island, NY to attend the practice rounds of the US Open. I met him at a rest area about 15 miles from my house. I couldn't understand why the trailer was handling as poorly as it did.

He was looking over the TV/TT setup, and noticed the drivers side tires on the TT looked "a little soft".

I dug out my pen style tire gauge from the tool kit, and sure enough both tires were down to around 35 psi (and this was with the tires hot) and the passenger side were down to about 42-45 psi. I took out my 12v air compressor, and attempted to fill them, but couldn't get the chuck to properly engage the stems. Luckily, Dad had a 12v unit in his truck. Needless to say, our planned 10 meet up at the rest stop turned into a 45 minute tire stop, and the TT handled much better for the rest of the trip.

I was running late for our planned meeting time, and never checked the tires before I left, when I had the air available from the big compressor. I won't do that again.

Tim


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## hurricaneplumber (Apr 12, 2004)

Jolly,

I learned more about this. It appears that on a motorhome it is much more critical about the weight each tire is carrying, Especially when they have a tandem set in the rear as well as a single axle in the rear (like a bus does).

I will be keeping my TT at 50 PSI, and my truck around 45-50 PSI.

One thing is for sure, there is no perfect situation. If there was this would all be easy and we would have nothing to talk about...

Kevin


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## j1mfrog (Jun 6, 2004)

j1mfrog said:


> http://www.jcwhitney.com/webapp/wcs/stores...1&storeId=10101
> 
> Are they worth it? Are they accurate?


So far, so good. Only had 1 show yellow so far and it was a few pounds low. Been verifying good pressure in all that indicated green. Quick easy peace of mind to walk around camper/truck and see green without bending down to check pressure 8 times. Boy, I AM getting old.


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## CamperDC (Oct 30, 2003)

Thanks for the report. I think I will give these a try as well.


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## Ymryl (Mar 2, 2004)

I've been considering the "Smarttire" system. The optional remote display shows the cold pressure of each tire within the first hundred feet you pull the trailer and shows the current pressure as you are driving.
They have it at the TireRack.com ($229 for the basic system - 4 wheels and $50 for the optional remote display). Might be a good thing to do next winter.

Smarttire System:









Optional Display:


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## j1mfrog (Jun 6, 2004)

Over 5000 miles later and I still like them.









Accurate and reliable so far.


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## Mgonzo2u (Aug 3, 2004)

This seems like a decent deal from Radio Shack, so I'll buy it to go along with my old fashioned stick pressure gauge.

http://www.radioshack.com/product.asp?cata...5Fid=63%2D1114#


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## slman (Jan 21, 2012)

j1mfrog said:


> j1mfrog said:
> 
> 
> > http://www.jcwhitney.com/webapp/wcs/stores...1&storeId=10101
> ...


Well I just retired, and off in a week, so checking all my tires on a 23' kangaroo, it was uncanny---all were at 36 lbs.

So I recon, with fully loaded I will take the advice given here and go with a full 50 lbs each wheel. 
By the way,----the Temp. in Medford Oregon today under the rv cover is 34 degrees with no ice melting so far off the truck bed or pond. This may have a bit to do with the low 36 lb. reading


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## KTMRacer (Jun 28, 2010)

j1mfrog said:


> Correct tire pressure in the Trailer and Tow Vehicle is very important and should be checked often. The problem is, I'm lazy, soooooo....
> 
> Anyone use these valve cap monitors?
> 
> ...


Here is how they work.

The open (depress) the normal valve core spring so air pressure is behind the indicator. So, unless they seal very well, they can leak around the threads. Only you can decide if it's worth the risk of ending up with a flat tire from a thread leak. If they are a plastic body, I can tell you they don't always last. Metal bodies with an o-ring to seal may be better.

Personally, I rely on a good tire gauge and a TPMS for the trailer tires.


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## Bill & Kate (Apr 28, 2012)

j1mfrog said:


> Correct tire pressure in the Trailer and Tow Vehicle is very important and should be checked often. The problem is, I'm lazy, soooooo....
> 
> Anyone use these valve cap monitors?
> 
> ...


I have had a set of SecuTire monitors on our trailer for 4-5 years. They are only an alarm that goes off it the tire pressure goes below like 30 psi. It is my hope that would be enough warning to get off the road and check to see what's wrong before a tire self destructs. The set was much cheaper than other systems, and a little inconvenient in that you have to take the sensor off the tire stem to actually check the pressure, but I think the system is definitely worth the price. Do a web search - these have been around for a while, and there are multiple discussions.

SecuTire


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## raynardo (Jun 8, 2007)

*SmarTire for Recreational Vehicles*
*SmarTire products are no longer available in the recreational vehicle market and the company has ceased support for this product category.*

Parts may be available at your local dealer, however, we retain no inventory to support service parts.


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## j1mfrog (Jun 6, 2004)

Hard to believe this thread from 2004 is still alive. The pressure caps worked well, but I don't use them anymore. I just keep a good pressure gauge in the TV door and check pressure before leaving a site.


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