Tire Pressure changing

Ford truck guy · 04-09-2021, 07:31 PM

Well, I have been driving either RV's or Big Rigs for close to 40 years.. I ALWAYS check the tires at EVERY stop.. mind you, it was the "Old School " way by thumping them...

I just installed my first TST system and was concerned at first.....I set the system up and installed mid afternoon, it was mid 60's.. ALL my tires were at 115.... came out the next AM ( it was 48 out)and to my surprise they were at 109 - 111 - 110 - 109..

I was concerned at first thinking 6 lbs was too much.. I called the good folks at TST and they told me its very common, told me to check them during the same time frame, close to the same temps....

Low and Behold... all at 115 - 115 -115- -115.. I was shocked to know that there was that much change with 15 degrees . . . . .

I think I'm gonna like this TST 507

although it may be Too Much Info for me while driving ! ! !

Jim & Mary · 04-09-2021, 10:53 PM

Joe
I've had mine for four years or so and my only complaint is first with the monochrome display and then with the color, i can't get it bright enough to see while wearing sunglasses on a bright sunny day. I would think if the truck display can be read the TST display should be as well. They included a trailer repeater when I bought the system, but haven't had to use it yet.

mhs4771 · 04-09-2021, 11:21 PM

Hey Joe, we were up in Savannah last week and the morning we left the temp was in the mid 30's and my TST was going off with low pressure. Just muted the alarm and left, within a few miles they had warmed up enough to stop the alarm.

Ford truck guy · 04-10-2021, 01:32 AM

Quote:

Originally Posted by Jim & Mary

Joe
I've had mine for four years or so and my only complaint is first with the monochrome display and then with the color, i can't get it bright enough to see while wearing sunglasses on a bright sunny day. I would think if the truck display can be read the TST display should be as well. They included a trailer repeater when I bought the system, but haven't had to use it yet.

Thanks Jim, I am leaving Sunday for the first trip so we will see how easy or hard it is to see the grayscale I version I chose...

Ford truck guy · 04-10-2021, 01:34 AM

Quote:

Originally Posted by mhs4771

Hey Joe, we were up in Savannah last week and the morning we left the temp was in the mid 30's and my TST was going off with low pressure. Just muted the alarm and left, within a few miles they had warmed up enough to stop the alarm.

Thanks Michelle,

I always knew the temps varied, just was surprised that much with that little if a temp swing... I'm excited to try it out

markw · 04-10-2021, 02:59 AM

Wait till you see the change on a hot day.
Mark

**piper guy** · 04-10-2021, 05:53 AM

Jim - if your sunglasses are polarized, that can cause viewing problems on screens.

almcc · 04-10-2021, 01:07 PM

The other thing that you may see on a hot day is that the high temp warning goes off on your left front truck tire if you come to a stop (say at a traffic light) and keep the diesel engine running. The heat from the engine seems to come out in that direction and heats up the tire! Depends on what temp you set the high temp warning at.

travelin' texans · 04-10-2021, 03:24 PM

Quote:

Originally Posted by Jim & Mary

Joe
I've had mine for four years or so and my only complaint is first with the monochrome display and then with the color, i can't get it bright enough to see while wearing sunglasses on a bright sunny day. I would think if the truck display can be read the TST display should be as well. They included a trailer repeater when I bought the system, but haven't had to use it yet.

Jim, Your sunglasses are probably Polarized, mine are also & can barely see my phone display with them in.
Joe, if you think that's shocking watch the temps while traveling in 100+ degrees on fresh black asphalt, 5 or 6 degrees is nothing.

MichaelA · 04-10-2021, 03:35 PM

Go to a racetrack.... Before going on-track, i air my vette down to 26 degrees. My target ‘hot’ tire pressure is 34 psi. In just 10-ish minutes I’ve achieved that type of rise in air pressure.

Each time I exit the track into the pits, I immediately check the pressure. Bleed off anything above 34 psi..

I know.... apples/oranges/totallyunrelated but was the first useless bit of info that popped into my head.

mhs4771 · 04-10-2021, 04:01 PM

I first set my TST high limit at their suggested 20%, since I'm running 125# that put it at 150, first time out in near 100 degree temps it went off as tires approached 151, so raised limit to 155 and no problems since.

Ford truck guy · 04-11-2021, 01:30 AM

Donald Wiesehan set my pressures and I hate to say this, but I am ASSUMING the HIGH is set at 138psi which is 20% of the set psi I gave him which is 115..

I somehow misplaced all the paperwork that came with, so until I find that, I won't know if he noted that info... I do know he noted 115, thats all I got

On edits.... found it! 144#- 25% is the high... 103# 10.3% is the low

**Blenhardt** · 04-17-2021, 03:47 PM

I too have the TST system and like it. My question is how high a pressure is too much for my Goodyear G114 tires after setting to the recommended 110psi when cold? On a hot day they will climb to a little over 130 psi??

mhs4771 · 04-17-2021, 04:02 PM

Blenhardt, double check the ratings on those tires, G614 are 110 and G114 are 125. With my previous G114s set at 125 I had to raise my high limit to 155 because on a hot day they would hit 150 and set off the alarm.

travelin' texans · 04-17-2021, 04:29 PM

Quote:

Originally Posted by mhs4771

Blenhardt, double check the ratings on those tires, G614 are 110 and G114 are 125. With my previous G114s set at 125 I had to raise my high limit to 155 because on a hot day they would hit 150 and set off the alarm.

I agree with both the temps & pressures. It's not unusual to see 25-30+ psi increase in pressures on a very hot day on black asphalt.

Ozzie · 04-17-2021, 05:38 PM

FYI ... For a complete explanation of RV tire pressure and the effects of temperature and altitude changes see this link:

RECREATIONAL VEHICLE TIRE AND CARE GUIDE:

https://www.goodyearrvtires.com/pdfs...care-guide.pdf

Note: The RV tire guide does not cover the effects of the tire heating when travelling.

**Blenhardt** · 04-18-2021, 12:36 AM

Thanks for the feedback. I was wrong. I have G614's and inflate them at 110 cold. That's what I sometimes see, 25 to 30 because of heat.

Ford truck guy · 04-18-2021, 06:45 PM

My first trip with the TST was a week ago... 1st half was raining and my psi’s only increased from 115 to 125....
2nd half was sunny and mid 70’s... went up to 138-140... thinking I may have to raise the upper limit if traveling in the heat this summer considering i was within 5 psi at 70 degrees

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