Tire pressure
Thread Starter
Racer
Joined: Nov 2013
Posts: 271
Likes: 38
Tire pressure
I get a warning that the left front tire pressure is down to 21 pounds. I get the tire filled, and a few weeks later, I get the same message again.
It is ALWAYS the left front tire, and the pressure is ALWAYS 21 pounds.
This is an ongoing problem - has happened at least a dozen times.
So why ALWAYS 21 pounds? Why not 20? or 18? or 23? Why 21?
Both the dealership and Goodyear say there is no discernable leak in the tire.
It is ALWAYS the left front tire, and the pressure is ALWAYS 21 pounds.
This is an ongoing problem - has happened at least a dozen times.
So why ALWAYS 21 pounds? Why not 20? or 18? or 23? Why 21?
Both the dealership and Goodyear say there is no discernable leak in the tire.
Le Mans Master
Joined: Sep 2003
Posts: 8,847
Likes: 795
From: Longview Texas
Maybe there is a leak at the bead that seals off when the pressure gets lower. Might help to clean the bead and let the tire reseat. Are all the weights stick on? I have had small leaks at the bead caused by clip on weights.
You might try bleeding more air out of the tire and see if the readout drops below the 21 lbs.
You might try bleeding more air out of the tire and see if the readout drops below the 21 lbs.
Last edited by TEXHAWK0; Dec 8, 2017 at 08:18 PM.
Team Owner
Joined: Sep 2000
Posts: 25,009
Likes: 2,707
From: Far NW 'burbs of Chicago
St. Jude Donor '13
Maybe there is a leak at the bead that seals off when the pressure gets lower. Might help to clean the bead and let the tire reseat. Are all the weights stick on? I have had small leaks at the bead caused by clip on weights.
You might try bleeding more air out of the tire and see if the readout drops below the 21 lbs.
You might try bleeding more air out of the tire and see if the readout drops below the 21 lbs.
The experts will explain this to us...
Le Mans Master
Joined: Sep 2003
Posts: 8,847
Likes: 795
From: Longview Texas
I forget because I bought a tool to read and trigger the sensors so I can read what the output is anytime.
Team Owner
Joined: Apr 2013
Posts: 26,228
Likes: 4,356
From: Chirper Island
Solved the leak.
I have no idea why it started leaking tens of thousands of miles after the tire change.
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Melting Slicks
Joined: Oct 2004
Posts: 2,083
Likes: 710
From: Sunnyvale CA
I once had a new tire that had a slow leak. Several shops couldn't find the problem which turned out to a little rubber piece in the bead. It wouldn't leak when off the car but would when driven.
Last edited by Grand Slam; Dec 9, 2017 at 07:12 PM.
Le Mans Master
Joined: Sep 2003
Posts: 8,847
Likes: 795
From: Longview Texas
Makes me wonder why you had to adjust more often... I doubt the apparent lower fluctuations is due to the nitrogen, but rather just that bottled nitrogen has less moisture to expand... The nitrogen itself behaves by the the same gas laws as oxygen, argon, and all the other gases.
If the oxygen molecule leaks out faster than the nitrogen molecules, then over time, all the oxygen would leak out, so that even if you replaced the 20% oxygen with air (78% nitrogen), the tire would eventually contain only nitrogen..
Consumer Reports did a study in 2006 where they measured pressure loss of nitrogen-filled Vs air-filled tires over a one year period. They took 31 pairs of all season, automotive tires (H and V speed rated). One tire of each pair was filled to 30 psi with air, the other tire from the pair was filled to 30 psi with nitrogen. All 31 pairs were then set aside, outdoors for 12 months.
Their conclusion was that nitrogen does reduce tire pressure loss over time, but the reduction is only 1.3 psi.
Last edited by TEXHAWK0; Dec 10, 2017 at 01:52 PM.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,953
Likes: 12,364
From: NE South Carolina
I get a warning that the left front tire pressure is down to 21 pounds. I get the tire filled, and a few weeks later, I get the same message again.
It is ALWAYS the left front tire, and the pressure is ALWAYS 21 pounds.
This is an ongoing problem - has happened at least a dozen times.
So why ALWAYS 21 pounds? Why not 20? or 18? or 23? Why 21?
Both the dealership and Goodyear say there is no discernable leak in the tire.
It is ALWAYS the left front tire, and the pressure is ALWAYS 21 pounds.
This is an ongoing problem - has happened at least a dozen times.
So why ALWAYS 21 pounds? Why not 20? or 18? or 23? Why 21?
Both the dealership and Goodyear say there is no discernable leak in the tire.
Could be a slow leaking valve or a bean not sealing on the rim! Have the tire removed and remounted. Or put soap solution on the tire valve and bead yourself and see if there are any fine bubbles. !
a tire dosn't go down for no reason!
Just Sayn'!
Safety Car
Joined: Sep 2015
Posts: 4,785
Likes: 1,417
Hmm, sounds like the first time it happened you should have been more worried about why it was getting lower rather than why it was 21 and not 22 or 23 pounds! If it happened a dozen times you should find out the cause!
Could be a slow leaking valve or a bean not sealing on the rim! Have the tire removed and remounted. Or put soap solution on the tire valve and bead yourself and see if there are any fine bubbles. !
a tire dosn't go down for no reason!
Just Sayn'!
Could be a slow leaking valve or a bean not sealing on the rim! Have the tire removed and remounted. Or put soap solution on the tire valve and bead yourself and see if there are any fine bubbles. !
a tire dosn't go down for no reason!
Just Sayn'!
Intermediate
Joined: Nov 2005
Posts: 38
Likes: 6
From: Ashburn Va.
My new Grand Sports left rear would lose 3-4 psi/week, I told the dealer about it at the 500 mile oil change servuce and they discovered the the TP sensor was leaking. They replaced it and it has been fine.
Intermediate
Joined: Jun 2017
Posts: 34
Likes: 8
I use air and still only have to adjust the pressures when the seasons change and I need adjust for a shift in ambient temperature...I do try to adjust the pressures when the humidity is low..
Makes me wonder why you had to adjust more often... I doubt the apparent lower fluctuations is due to the nitrogen, but rather just that bottled nitrogen has less moisture to expand... The nitrogen itself behaves by the the same gas laws as oxygen, argon, and all the other gases.
If the oxygen molecule leaks out faster than the nitrogen molecules, then over time, all the oxygen would leak out, so that even if you replaced the 20% oxygen with air (78% nitrogen), the tire would eventually contain only nitrogen..
Consumer Reports did a study in 2006 where they measured pressure loss of nitrogen-filled Vs air-filled tires over a one year period. They took 31 pairs of all season, automotive tires (H and V speed rated). One tire of each pair was filled to 30 psi with air, the other tire from the pair was filled to 30 psi with nitrogen. All 31 pairs were then set aside, outdoors for 12 months.
Their conclusion was that nitrogen does reduce tire pressure loss over time, but the reduction is only 1.3 psi.
Makes me wonder why you had to adjust more often... I doubt the apparent lower fluctuations is due to the nitrogen, but rather just that bottled nitrogen has less moisture to expand... The nitrogen itself behaves by the the same gas laws as oxygen, argon, and all the other gases.
If the oxygen molecule leaks out faster than the nitrogen molecules, then over time, all the oxygen would leak out, so that even if you replaced the 20% oxygen with air (78% nitrogen), the tire would eventually contain only nitrogen..
Consumer Reports did a study in 2006 where they measured pressure loss of nitrogen-filled Vs air-filled tires over a one year period. They took 31 pairs of all season, automotive tires (H and V speed rated). One tire of each pair was filled to 30 psi with air, the other tire from the pair was filled to 30 psi with nitrogen. All 31 pairs were then set aside, outdoors for 12 months.
Their conclusion was that nitrogen does reduce tire pressure loss over time, but the reduction is only 1.3 psi.