TPM Nut Seal....Check them !
Thread Starter
Safety Car
Joined: Dec 2010
Posts: 3,938
Likes: 498
From: Fords, NJ
TPM Nut Seal....Check them !
I have been experiencing a slow leak on my left front tire for the past 2 months. Every time I'd fill it to 30 psi in a matter of 2 weeks it would leak down again to about 23 to 25 psi. I couldn't find anything in the tread area so I figured i'd have to take it to the shop. So like a dope, I'm standing at the front of the car staring at the wheel and then it hit me.
Got a 1/4 " drive deep socket ( can't remember size) and checked the TPM nut. I was able to get a full turn and a half on it before it snugged up. While i was at it I checked the rest of the wheels. I was able to pull up on the rest anywhere from a 1/2 to 3/4 of a turn before they got snug.
Left front tire has been holding pressure !
I dunno if this was just a fluke or what but from now one I'll make it a point to check them at least twice a year
Got a 1/4 " drive deep socket ( can't remember size) and checked the TPM nut. I was able to get a full turn and a half on it before it snugged up. While i was at it I checked the rest of the wheels. I was able to pull up on the rest anywhere from a 1/2 to 3/4 of a turn before they got snug.
Left front tire has been holding pressure !
I dunno if this was just a fluke or what but from now one I'll make it a point to check them at least twice a year
Last edited by SG Lou; Apr 8, 2016 at 08:43 PM.
Administrator
Joined: Mar 2001
Posts: 368,399
Likes: 24,797
From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03 thru '26
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
Good that you found the source of the leak and it didn't cost you anything but some time.
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
The torque specs for the TPMS nut are:
Early '97-'00 = 106 in lbs
Late '01-'04 = 62 in lbs
The early sensors use an oring and the late sensors use a formed gasket or grommet.
The best price I have seen for the service kits (seal, valve core, nut, cap) is $1 or less at Rock Auto.
Early '97-'00 = 106 in lbs
Late '01-'04 = 62 in lbs
The early sensors use an oring and the late sensors use a formed gasket or grommet.
The best price I have seen for the service kits (seal, valve core, nut, cap) is $1 or less at Rock Auto.
Team Owner
Joined: May 2001
Posts: 87,375
Likes: 1,593
From: Western NY
Thread Starter
Safety Car
Joined: Dec 2010
Posts: 3,938
Likes: 498
From: Fords, NJ
Thread Starter
Safety Car
Joined: Dec 2010
Posts: 3,938
Likes: 498
From: Fords, NJ
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
I have read that there are differences between the printed manuals and the dealer's electronic ones. The dealer's show 62. I have also read that there was a service bulletin that changed the spec from 35 to 62. I took a brief look though and could not find the bulletin. I will update if I find it.
The Schrader (OEM manufacturer) spec for torque is 62. This might be confusing because the Scrader spec for the early sensors is also 62, but I don't know if they changed the oring to a formed gasket on the aftermarket sensors so the early and late torques might be the same now for Schrader aftermarket. Some of the pictures of new early style Schrader appear to have the later seal.
The export vehicles used the early style sensors so the 106 matches to the early sensors.
The Schrader (OEM manufacturer) spec for torque is 62. This might be confusing because the Scrader spec for the early sensors is also 62, but I don't know if they changed the oring to a formed gasket on the aftermarket sensors so the early and late torques might be the same now for Schrader aftermarket. Some of the pictures of new early style Schrader appear to have the later seal.
The export vehicles used the early style sensors so the 106 matches to the early sensors.
Thread Starter
Safety Car
Joined: Dec 2010
Posts: 3,938
Likes: 498
From: Fords, NJ
Yes, that is confusing. Please let us know if you come across that bulletin you referenced.
All I can say is, when my new tires and sensors were mounted, I told the tire guy to use 35 lb in and mine haven't leaked yet. It's been probably a year or more so I might just try and see if they're still at that spec, and if not bring them up to at least 35 lb in. I don't want to take a chance of over-torqueing them, and as long as they're not leaking, all should be good (as far as I'm concerned).
All I can say is, when my new tires and sensors were mounted, I told the tire guy to use 35 lb in and mine haven't leaked yet. It's been probably a year or more so I might just try and see if they're still at that spec, and if not bring them up to at least 35 lb in. I don't want to take a chance of over-torqueing them, and as long as they're not leaking, all should be good (as far as I'm concerned).
1/4" or 3/8" drive or both ?
Last edited by SG Lou; Apr 10, 2016 at 11:34 PM.
Thread Starter
Safety Car
Joined: Dec 2010
Posts: 3,938
Likes: 498
From: Fords, NJ
OK then, I'll buy both
Team Owner
Joined: May 2001
Posts: 87,375
Likes: 1,593
From: Western NY
Just to throw my $0.02 in on the torque value. In reality, you need the nut to apply enough force to adequately seal the valve stem, you not enough to damage the seal or the sensor. You also need the nut to have enough torque applied to it so it remains tight.
IMHO, a minimum level of torque, so the seal doesn't distort, but a drop of blue Loctite on the threads, so the nut remains tight, will work well.
IMHO, a minimum level of torque, so the seal doesn't distort, but a drop of blue Loctite on the threads, so the nut remains tight, will work well.
Thread Starter
Safety Car
Joined: Dec 2010
Posts: 3,938
Likes: 498
From: Fords, NJ
Just to throw my $0.02 in on the torque value. In reality, you need the nut to apply enough force to adequately seal the valve stem, you not enough to damage the seal or the sensor. You also need the nut to have enough torque applied to it so it remains tight.
IMHO, a minimum level of torque, so the seal doesn't distort, but a drop of blue Loctite on the threads, so the nut remains tight, will work well.
IMHO, a minimum level of torque, so the seal doesn't distort, but a drop of blue Loctite on the threads, so the nut remains tight, will work well.
Team Owner
Joined: May 2001
Posts: 87,375
Likes: 1,593
From: Western NY
I took the wheels were off the car, however, and I set the wheels on my workbench, upside down, oriented so the sensors were hanging over the edge of the bench, and fortunately, gravity held them in place, while I R&Red the nuts. I was very careful, however, not to push on the stems, while the nuts were off.