Community Forums

TXBart · 05-05-2014, 11:02 AM

I'm setting up my TPMS. The gage on my air chuck, my truck gage and the TPMS pressure do not agree.

How close do you set pressures to the TPMS reading?

This is not a tool for someone who is the least anal retentive!

MRUSA14 · 05-05-2014, 11:03 AM

Mine agree within 1 or 2 PSI. What is the varaince on yours?

thrushl · 05-05-2014, 11:09 AM

Quote:

Originally Posted by MRUSA14

Mine agree within 1 or 2 PSI. What is the varaince on yours?

x2 Same here. I have a high-end digital gauge om my nitrogen tire fill tank that is guaranteed to be +/- 1/2 PSI and it is bang on to my TPMS. Not saying my TPMS is always that close, but it is when the ties are cold.

TXBart · 05-05-2014, 11:15 AM

At least 5-8 psi. I am using analog gages outside which is part of the problem. I am using my garage compressor which is 130 psi, 25 gallon, 5.5 hp. When the compressor is running it inflates in a hurry, when it's idle it's very slow. I am also learning that the update rate on the display is not immediate so.......

Another issue is sunshine; the right side of the coach is in the sun, left in the shade which appears to impact pressure.

To clarify the question, if pressure is supposed to be 95 how close do you get the reading on the TPMS? My nature is to get it to read 95 but I also want to go someplace in the coach and not make a career out of getting pressures exact!

**pasdad1** · 05-05-2014, 11:18 AM

Set the pressure earlier in the day before the sun becomes a factor. Get a good quality handheld digital gage and set the pressure using that as your sole reference....don't worry what the TPMS is reading at that moment. If the TPMS readings are within 5% don't sweat it! it is more useful to see trends than exact pressures....also look for tires that read more than 5% different than the others as a sign that something unusual is happening .

MRUSA14 · 05-05-2014, 11:22 AM

I would first take your tire guage to a tire center and check it against a known accurate one. This way you will know if it is your guage or your TPS that is in error, or both. Assuming your guage is accurate I would not worry about a discrepancy in the TPS. The role of that is to alert you af any change in pressure. The TPS indicated presuure level is not really that important, but the change is pressure is what will get you.

TXBart · 05-05-2014, 02:58 PM

I finally got it all set up, less one sensor. I set all the tires at recommended pressure at the tire with a digital gage then took what the TPMS showed. It is generally within 2-3 psi.

One sensor quit. It showed 78 psi then after a little air went to 116. It was hard to push air through the quit letting air out or in all together. Pressure without it is set to 95 so I will use it as a failure indicator until TST sends me a new sensor. It did the same on other tires.

I went about it the wrong way and this 45 minute job took me almost all day!

Sky_Boss · 05-05-2014, 03:12 PM

Generally, my TST TPMS runs within 2 PSI of my hand held gauge. for the most part the TPMS runs lower than my gauge. I like that because it will trip off low pressure faster that way. My gauge is pretty darn good so I trust it but it is nice that the TPMS seems to agree.

hogdriver · 05-05-2014, 11:27 PM

Quote:

Originally Posted by TXBart

I finally got it all set up, less one sensor. I set all the tires at recommended pressure at the tire with a digital gage then took what the TPMS showed. It is generally within 2-3 psi.

One sensor quit. It showed 78 psi then after a little air went to 116. It was hard to push air through the quit letting air out or in all together. Pressure without it is set to 95 so I will use it as a failure indicator until TST sends me a new sensor. It did the same on other tires.

I went about it the wrong way and this 45 minute job took me almost all day!

I have had problems with the sensors sitting on the 3 inch tire stem extensions. I had to order a couple new extensions $3 ea.

TXBart · 05-06-2014, 06:45 AM

The sensors on my inner duals are a little close to the edge of the hole they come through but aren't touching it, so far.

hogdriver · 05-06-2014, 07:14 AM

Be careful if your valve extensions have any leverage caused by the sensors. I think that is what caused one of my stems to develop a fracture.

Dr4Film · 05-06-2014, 07:17 AM

TPM systems do not have to be exactly synchronized and accurate with your tire pressure gauge.

What is important is that your tire gauge be accurate therefore you should purchase a good one and then have it calibrated to a known accurate gauge from a reputable tire shop.

That should be done every year or so.

Once you set the parameters on your TPMS to your baseline PSI's along with the alarms set points, it is really a matter of relativity. If a tire goes down in psi by 12% or whatever your set point is then it will alarm you to the fact.

You should be more concerned about the differential versus the absolute.

BTW, I use THIS tire gauge and it has been dead nuts from the day I purchased it without any changes to the calibration.

Dr4Film ----- Richard