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TPMS and/or pressure gauge
I just bought a set of TPMS sensors to put on the new to us rig we'll be picking up on Saturday (yay!). Whilst shopping for Eternabond and other stuff that we'll be using, I put a tire pressure gauge in the Amazon shopping cart, whereupon my dear partner said, "isn't that redundant, since you'll be installing TPMS"? I did not have a worthwhile response, so I'm going to ask the forum - what would a good answer have been? She has a point, doesn't she?
2003 MB
Formerly 1997 TK

Re: TPMS and/or pressure gauge
Reply #1
A TPMS is a very important addition to your RV travel safety. That being said, the TPMS only monitors the tire pressure that is in the tire. It does not inflate nor does it maintain the tire’s air pressure.

The tires must first be properly inflated before the TPMS can detect the pressure in the tires. A quality tire air pressure gauge is necessary to determine the air pressure you are adding to the tires. After that, the TPMS is there only to inform you of the current tire pressure.

Many RV owners use a digital pressure gauge. They are much easier to read than an analog dial style gauge and more accurate (depending on the gauge quality one would gather).

A quality portable air compressor is also recommended for your LD.

Happy travels.

Kent

2015 27' RB "MissB.Haven"

Re: TPMS and/or pressure gauge
Reply #2
A sensor can fail or give you a reading you want to double check for some reason.  Plus, you'll need to check your spare periodically.  Frank
plan B - 2023 Travato

Re: TPMS and/or pressure gauge
Reply #3
Trust, but verify.  ;)
Joel
Joel & Terry Wiley
dog Zeke
2013  31 IB   Orwan   / 2011 CRV Tow'd LWEROVE

Re: TPMS and/or pressure gauge
Reply #4
The sensors on my tires are quite accurate at tracking pressure changes, but are not as accurate at displaying the tire's actual pressure.  I use a digital pressure gauge to inflate my tires, getting a pressure within 1/2 PSI of my target pressure.  The sensors, reporting the pressures, display pressures that vary by several pounds.  However, they will report a pressure drop very accurately.  Other systems might work differently, but mine stores individual tire pressure settings and tests for changes against that stored number, thus they are quite reliable to monitor pressure, but not very good for setting a pressure.  That's why I use a digital pressure gauge.

Ken F in NM
'08 MB


Re: TPMS and/or pressure gauge
Reply #6

If the new coach is not equipped with long valve stems on the inner dual wheels (might be worth checking), you may wish to consider an extended claw foot gauge like this:

Amazon.com: WYNNsky Extension Heavy Duty Straight-on Dual Head Service Tire...

As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Warren
2019 MB “Dream Catcher”
Jeep Wrangler JL

Re: TPMS and/or pressure gauge
Reply #7
<snip>
A quality portable air compressor is also recommended for your LD.

Happy travels.

Kent

Do you have a favorite compressor? I used to carry a jump start battery pack w/ a built in compressor, but I recently found out it doesn't have enough umpf to start the rig w/ a dead battery. I ended up getting a NOCO boost pack to handle the jump starting, but now I'm going to need a separate compressor.
2001 MB

Re: TPMS and/or pressure gauge
Reply #8
I purchased the Viair 400P RV compressor. Rather than purchasing the compressor on Amazon, I went directly to the manufacturer web site. 400P-RV Automatic Compressor | VIAIR

It is 12volt system, fairly compact and has a great following among LDOG members and Off Road enthusiasts.

Others here use compressors that are less costly and can do a good job at getting the job done. Like many of us, I’d rather not have a need to use it but if you are on a long trip it is advisable to maintain proper pressure in the tires.

Under inflation is a bad thing and can quickly ruin a very expensive tire. On top of that, an under inflated tire can cause a blow out. That’s the very last thing you want to experience in a heavy RV.

Enjoy your LD and safe travels.

Kent



2015 27' RB "MissB.Haven"


Re: TPMS and/or pressure gauge
Reply #10
As others have said, a handheld tire pressure gauge is useful for inflating a tire to the correct pressure.  With the TPMS I use, the sensors update about every five minutes.  I use flow-through sensors on the LD, but not on the toad, which would make it even more of a pain not to have a gauge.

Another consideration is that all the TPMS systems I know of measure absolute pressure, with the number displayed adjusted for sea level air pressure. A handheld tire pressure gauge measures the difference in pressure between inside and outside the tire, which is what you care about.  At higher altitude, a TPMS will read low compared to a gauge.

Re: TPMS and/or pressure gauge
Reply #11
I purchased the Viair 400P RV compressor. Rather than purchasing the compressor on Amazon, I went directly to the manufacturer web site. 400P-RV Automatic Compressor | VIAIR

It is 12volt system, fairly compact and has a great following among LDOG members and Off Road enthusiasts.
<snip>
Kent

I was looking at this one on Amazon, but the a few of the comments in the review where interesting. To quote from the amazon page:
"The Viair compressor excels at one thing. TOPPING OFF your tow vehicle and RV's tires. It's actually not really all that great at doing anything else. And if you happen to be an off roader looking for a compressor to re-inflate your big balloon tires after a day of muddin, I strongly suggest you do you homework on Viair compressors before pulling the trigger."

Looks like the 400P-RV has a 33% duty cycle and the 450P-RV has a 100% duty cycle, but lower CFM and power draw.

Anyone have thoughts on the 400 vs 450?
2001 MB

Re: TPMS and/or pressure gauge
Reply #12
Thanks all for the comments & suggestions.
I have a compressor at home, my old digital gauge conked out on me a few years back so I'll go with Joan's recommendation. I bought the TST 507 with flow through caps and will hopefully be installing these onto the Borg stems that will be installed with 6 fresh Michelin Agilis tires on Saturday. From there, it's back to Sacramento and camping out on the north 40!
2003 MB
Formerly 1997 TK

 
Re: TPMS and/or pressure gauge
Reply #13
"The Viair compressor excels at one thing. TOPPING OFF your tow vehicle and RV's tires. It's actually not really all that great at doing anything else. And if you happen to be an off roader looking for a compressor to re-inflate your big balloon tires after a day of muddin,

Looks like the 400P-RV has a 33% duty cycle and the 450P-RV has a 100% duty cycle, but lower CFM and power draw.
Anyone have thoughts on the 400 vs 450?

If you are going to use the compressor to add air to your LD's tires, almost any decent quality, small compressor will do the job as long as it is capable of easily reaching the highest pressure needed. 120-VAC compressors can be considered too, your rig has a generator.
Good tires, used with a TPMS, should not need frequent airing or not much when they do, no air is lost regularly checking the pressure when the TPMS system does that for you.
If a compressor is also going to be used to air up a 4X4's tires, after a day of off-roading, a small compressor is going to make you wait quite a while. Viair makes some very expensive compressors for such applications, overkill for topping off a LD's tire pressure.
For airing our Jeep's tires, a 10-lb, CO2 tank is carried. It's fast and powerful enough to run a full size,1/2" air impact wrench.
Once again, overkill for topping an RV's tire's pressure off.

For your LD's tire, the 400-RV is more than big enough, unless your tires are all flat, a 33% duty cycle will easily do the job. The 450-RV has a longer duty cycle because it is producing less compressed air, allowing it to run longer before overheating, it is more appropriate for airing up a 4X4's large tires.
Viair's RV compressors are very appropriate for Class As and DP tires, that run at much higher pressures than our tire's 80-psi maximum.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze