Losing Air in All Tires!

john_dough · 07-26-2009, 12:29 PM

I've had my 2008 with OEM tires for about 11 months and for the past month I've been having trouble keeping air in the tires. I normally run at 50psi/48psi. All four tires lose from 5 to 10 psi over a two week period. Has anyone seen this before? Thanks.

john1701a · 07-26-2009, 12:35 PM

Since the tires are only rated for 44 PSI max-cold and tires lose a little bit over time anyway, your experience is probably a realistic expectation.
.

**TonyPSchaefer** · 07-26-2009, 12:36 PM

I've only seen this in the Autumn as the temperature of the air in the tires drops and therefore, the psi. In the summer, I've never seen this.

I'm going to assume that you've already checked them for construction debris.

jayman · 07-26-2009, 12:37 PM

Leaky valve stems? Sabotage?

Vincent · 07-26-2009, 12:50 PM

Same problem with my 06 Gen II. Lot's of Florida Summer heat build up during the day that eventually leaks out of hyperinflated tires. Had much better luck controlling my medium (40/38) tire pressures when I switched to a Nitrogen fill (vs 78% nitrogen regular air).

Still playing with tire pressures on my Gen III; when I find a happy PSI, I'll go for a NitroFill again.

Try Nitrogen; Good Luck.

john_dough · 07-26-2009, 02:04 PM

Didn't realize psi limit is 44--my bad. Construction debris and vandalism have been eliminated. Visual check of tires shows no punctures. Valve stems are a possibility. I've reset pressures to 40/38 and will observe. Thank you all for the useful comments.

topkick · 07-26-2009, 03:15 PM

I had this problem with my 2007 Prius. Everytime I check the tires they had lost some pressure. I bought a valve stim tool and checked all the valve stims. All were not fully seated. I tightened each one, but only firm. Did not over tighten and never lost any more pressure.

My 2010 seems to be ok and I don't lose any pressure. I still want to check the stims if I can find my tool.

**TonyPSchaefer** · 07-26-2009, 03:25 PM

44 is a psi limit? Where's that written? I'm running 52f/50r and haven't had a problem with air leakage.

Patrick Wong · 07-26-2009, 03:44 PM

Quote:

Originally Posted by TonyPSchaefer

44 is a psi limit? Where's that written? ...

The maximum cold tire inflation pressure can be found on the sidewall of the tire. Typically this is 44 psi. It might be lower or it might be higher than that number, depending upon the tire brand/model in service.

**TonyPSchaefer** · 07-26-2009, 04:35 PM

Oh I know the sidewall rating. I must have misread the post. I thought it was being said that 44 was the upper maximum for the tires, not merely a rating.

07-26-2009, 12:29 PM	#1
john_dough Member Join Date: Aug 2008 Location: Florida Posts: 61 My Car: 2008 Prius Model: Package: #2 Thanks: 23 Thanked 2 Times in 1 Post Friends: 0	Losing Air in All Tires! I've had my 2008 with OEM tires for about 11 months and for the past month I've been having trouble keeping air in the tires. I normally run at 50psi/48psi. All four tires lose from 5 to 10 psi over a two week period. Has anyone seen this before? Thanks.

07-26-2009, 12:35 PM	#2
john1701a Senior Member Join Date: Jan 2004 Location: Minnesota Posts: 3,376 My Car: 2010 Prius Model: IV Package: Solar Roof Thanks: 9 Thanked 145 Times in 70 Posts Friends: 12	Re: Losing Air in All Tires! Since the tires are only rated for 44 PSI max-cold and tires lose a little bit over time anyway, your experience is probably a realistic expectation. .

07-26-2009, 12:36 PM	#3
TonyPSchaefer Your Friendly Moderator Join Date: May 2004 Location: Far-North Chicagoland Posts: 10,512 My Car: 2004 Prius Model: Package: #9 Thanks: 39 Thanked 168 Times in 109 Posts Friends: 23	Re: Losing Air in All Tires! I've only seen this in the Autumn as the temperature of the air in the tires drops and therefore, the psi. In the summer, I've never seen this. I'm going to assume that you've already checked them for construction debris.

07-26-2009, 12:37 PM	#4
jayman Senior Member Join Date: Oct 2004 Location: Winnipeg Manitoba Posts: 11,576 My Car: 2004 Prius Model: Package: B Thanks: 35 Thanked 186 Times in 169 Posts Friends: 12	Re: Losing Air in All Tires! Leaky valve stems? Sabotage?

07-26-2009, 12:50 PM	#5
Vincent Don't Wait Until Tomorrow Join Date: Sep 2005 Location: South Florida Posts: 635 My Car: 2010 Prius Model: V Package: Navigation Thanks: 0 Thanked 21 Times in 13 Posts Friends: 0	Re: Losing Air in All Tires! Same problem with my 06 Gen II. Lot's of Florida Summer heat build up during the day that eventually leaks out of hyperinflated tires. Had much better luck controlling my medium (40/38) tire pressures when I switched to a Nitrogen fill (vs 78% nitrogen regular air). Still playing with tire pressures on my Gen III; when I find a happy PSI, I'll go for a NitroFill again. Try Nitrogen; Good Luck. Last edited by Vincent; 07-26-2009 at 12:53 PM.

07-26-2009, 02:04 PM	#6
john_dough Member Join Date: Aug 2008 Location: Florida Posts: 61 My Car: 2008 Prius Model: Package: #2 Thanks: 23 Thanked 2 Times in 1 Post Friends: 0	Re: Losing Air in All Tires! Didn't realize psi limit is 44--my bad. Construction debris and vandalism have been eliminated. Visual check of tires shows no punctures. Valve stems are a possibility. I've reset pressures to 40/38 and will observe. Thank you all for the useful comments.

07-26-2009, 03:15 PM	#7
topkick Senior Member Join Date: Jun 2007 Location: Oklahoma City Posts: 155 My Car: 2010 Prius Model: IV Package: Navigation Thanks: 8 Thanked 20 Times in 13 Posts Friends: 0	Re: Losing Air in All Tires! I had this problem with my 2007 Prius. Everytime I check the tires they had lost some pressure. I bought a valve stim tool and checked all the valve stims. All were not fully seated. I tightened each one, but only firm. Did not over tighten and never lost any more pressure. My 2010 seems to be ok and I don't lose any pressure. I still want to check the stims if I can find my tool.

07-26-2009, 03:25 PM	#8
TonyPSchaefer Your Friendly Moderator Join Date: May 2004 Location: Far-North Chicagoland Posts: 10,512 My Car: 2004 Prius Model: Package: #9 Thanks: 39 Thanked 168 Times in 109 Posts Friends: 23	Re: Losing Air in All Tires! 44 is a psi limit? Where's that written? I'm running 52f/50r and haven't had a problem with air leakage.

07-26-2009, 04:35 PM	#10
TonyPSchaefer Your Friendly Moderator Join Date: May 2004 Location: Far-North Chicagoland Posts: 10,512 My Car: 2004 Prius Model: Package: #9 Thanks: 39 Thanked 168 Times in 109 Posts Friends: 23	Re: Losing Air in All Tires! Oh I know the sidewall rating. I must have misread the post. I thought it was being said that 44 was the upper maximum for the tires, not merely a rating.

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