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Fixing a slow leak in tire help

Discussion in 'Prime Care, Maintenance and Troubleshooting' started by GKL, Oct 10, 2021.

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  1. GKL

    GKL Active Member

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    Interesting, thanks for sharing that !

    So when you mentioned "higher pressures I saw suggested here" how high were those suggested pressures ?

    So if the label on the door of my car says 35psi for rear tires and 36psi for front tires maybe do about 38psi rear and 39psi front ?

    (I definitely want to void squeaks and rattles and not over-inflate too much !)
     
  2. GKL

    GKL Active Member

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    Okay, thanks, somehow I don't remember having as much issues with maintaining tire pressure in past cars I've had.

    Maybe check tire pressure once a month ?

    So would about 3lbs over what the door label says be okay without causing too rough of a ride ?

    I'm retired and some days my car might sit till afternoon before it gets driven, if I check the air pressure in the afternoon (car sitting undriven up to that point) about what pressure should I expect to see if the cold pressure on the label says 35psi ?

    If I add air in the afternoon and want to have it about 3lbs over the label's cold pressure of 35psi, I'm guessing it would be more than 38 as 38 would be if I added air in the morning.
     
  3. ChapmanF

    ChapmanF Senior Member

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    I kind of eventually settled on 38/36, where the door sill numbers were 35/33, so about 3 psi over.

    When I got my first Prius and joined PriusChat, I was briefly in the influence of some enthusiasts hyping pressures near the sidewall maximum, but I couldn't stand it myself, and I regretted what it did to the dash.

    I have reset my TPMS by inflating the tires first to sidewall max, pressing the TPMS "ok, remember this pressure" button, then lowering them to the pressure I want. That gives me a pretty early TPMS warning when they get a little low, which is the way I like it. If you push the "remember this" button at the pressures you actually want, it doesn't give the warning until the tires are quite squishy.

    Might not be to everybody's taste though, because it ends up giving the light fairly often in transitional weather (like now), and airing the tires back up just the small amount required isn't always enough to douse the light right away, so it stays on for a while.
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    If you’re not that familiar with changing tires:

    slightly loosen the lug nuts before raising the car; it’s a lot easier than when the wheel’s off the ground, free to spin.

    And vice versa when reinstalling.

    If you don’t have a torque wrench (lug nut spec is 76 ft/lb, per attachment I posted previous), snug them with medium/strong effort, verify with torque wrench when you can.
     
  5. bisco

    bisco cookie crumbler

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    i pump to 42/40. then ignore them. it takes a long time to get back near spec, then i pump up again.

    the ride is a bit harsh on rough roads
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    I like to set them all to the same pressure, a pound or two over front tire spec pressure.
     
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  7. bisco

    bisco cookie crumbler

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    why the same mendel?
     
  8. Salamander_King

    Salamander_King Senior Member

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    I do the same as Mendel. Set all four tires at 38ish. It's easier to remember and maintain that way. And I don't have to do any adjustments when rotating tires.
     
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  9. bisco

    bisco cookie crumbler

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    so toyota recommends the differential for no reason? i always thought it was because of engine weight
     
  10. Salamander_King

    Salamander_King Senior Member

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    Yeah, I think that is the reason. But honestly, only a 1psi difference between the front (36psi) and the back (35psi), I doubt if that really makes difference in real-world day-to-day driving conditions. If I park my car for a while during the day, the side hit by the sun is almost 2psi higher than the other side.
     
    #30 Salamander_King, Oct 11, 2021
    Last edited: Oct 11, 2021
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  11. Mendel Leisk

    Mendel Leisk Senior Member

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    What he said.
     
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  12. BiomedO1

    BiomedO1 Senior Member

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    I also run 38 psi all the way around. I usually reinflate around now and check again on the next cold snap. Spring & summer heat takes care of itself - unless the TPM goes off. I usually check for nails/screws during tire rotations; which I won't have to do for another 18 months.:)
     
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  13. GKL

    GKL Active Member

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    At least for now I am trying about 3 psi over, definitely want to avoid ever being under-inflated though after my recent experience :rolleyes:
     
  14. GKL

    GKL Active Member

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    Good you brought that up, we can't assume auto shops are going to inflate our Prime tires to what we know they should be, I am going to post a post shortly with pics about how I resolved things from my recent experience which included getting 2 new tires, good thing I checked the pressure of my tires the next day before driving as they had only inflated the tires they installed to about 32-33 psi :eek:
     
  15. GKL

    GKL Active Member

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    The door label on my 2020 Prime says 35 rear and 36 front (cold) so I am trying 3 psi over those for now and see how that works.

    After my recent experience I might check my tire pressures at least once a week for right now (especially since we are getting into cooler and cooler weather now) then maybe would going to checking tire pressures about once a month should be okay ?
     
  16. GKL

    GKL Active Member

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    We decided to replace the tire that was driven on very under-inflated because the way it looked I was leery about trusting it at expressway speeds. My wife suggested we get 2 new tires installed which I agreed since we could use the good tire from the other side to use for a spare.

    I also kept the tire that was under-inflated as I wanted to see what caused the leak as well as how that worn area felt, and that worn area felt noticeably thinner so I am glad we decided to replace it, just not worth taking a chance to keep using it.

    I am going to post some pics, one will show the screw from the outside that caused the slow leak as well as once showing where it came thru on the inside. Another pic will show how the tire got worn from driving on it under-inflated (it was worn that way on both sides). I will also show pics that show the tires I got as well as the wheel I got. Also a pic showing where the jack is at under the back seat (and a question about getting it out)

    I needed to find a place that could have the tires I needed at least by the next day (I wanted to get a match for what was originally on the car) but also a place that had a discounted price, the lowest price I was able to find in our area was about $116 and I found a place that could fit us in the very next day, I guess I must have seemed hesitant enough to the person on the phone that he offered a coupon that would bring the price of the tires down to about $100 each so that was great, the place is called Mavis Tire and Break, never been there before, only real complaints was we asked for the new tires to be put on the front and they put them on the back (we didn't have time to wait for them to change it) and they only inflated the tires to 32-33 psi, so always check your tire pressures after having your car serviced.

    Note: the only tires available that fast was rated 89S instead of the 91S on the original tires, but the store said that should not be any problem since we don't usually haul extra heavy loads.

    I guess we'll just wait till the next time our car is due to have the tires rotated and simply have them put the newer ones on the front then (we have our routine maintenance service done at the dealership since they included the plan when we bought the car that made it no cost to have regular maintenance done)

    I found a place (Discount Tire Direct) that was on the way there that had the wheel I needed to put the good tire on to have a full size spare, the wheel was only $67 but I got the 10% off discount they offer to veterans. So now we have a full size spare I keep behind the driver's seat.

    Question about the jack under the rear seat, how easy is that to get out, does it simply fit thru the space to pull it out thru the top of the seat frame ?

    Another question, since we only needed to get 2 new tires now we wanted to match what was originally installed on the car, later on in the future when we would be ready to replace all 4 tires at once should we stay with the same tires or are there other tires that might be better but still around the same price range ?

    (note: the pic further down showing the worn area I should have said "an under-inflated tire" instead of tires since it was only one tire)

    inside view of cause of leak.jpg jack under back seat Prius Prime 2020 XLE.jpg outside view of cause of leak.jpg tires Mavis Tires and Brakes.jpg wheel 48991 Discount Tire Direct.jpg why to make sure tires are not underflated.jpg
     
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  17. burrito

    burrito Active Member

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    If replacing 2 tires, the new ones should always go on the back, regardless of whether the car is front- or rear-wheel drive.

    When it happened to me, I got charged a rotation fee to swap the old tires to the front. You saved a bit if they did that for you.
     
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  18. Mendel Leisk

    Mendel Leisk Senior Member

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    Just break down and get two more, lol? It seems like getting just two, you're in a conundrum, till the end of time: the newer tires on the back will never catch up.


    conundrum meaning - Google Search
     
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  19. Salamander_King

    Salamander_King Senior Member

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    Not sure what you are asking here, but you are showing the photo of the rear seats with cushions removed. If you are asking how to remove the scissors jack under the rear seats, there is an access door panel on the bottom side of the left rear seat. See the diagram below. You may have to turn the jack bolt a few turns to shorten the height to get it out. It is stored that way so that it does not rattle.

    upload_2021-10-14_15-53-17.png

    As long as the tire is the same size and speed and load range, it does not have to be identical, but the same brand with exactly the same tread pattern may be a good idea. Depending on how much treads are left on other two tires, you may never be able to wear them out evenly from now on. As commented already, the new tires are supposed to go to the rear. This means two somewhat worn tires are going to stay in front. With front-wheel-drive cars like PP, the front tires are going to wear faster than the rear. By the time it is time for you to rotate the tires for the next service, the front may be far more worn than the two new tires on the rear. If that is the case, rotating tires will never "catch-up" to even out the wear on all four tires. You may have to keep driving without rotating and keep replacing two tires at a time from now on. Or if you want to replace all four tires same time, you are likely to have two tires that have still a usable amount of tread left. I have read about "shaving" good tires to even out the tread depth, but have never seen such service offered by any tire shops I have visited.

    Your OEM tire was Dunlop Enasave. It comes with very thin treads to begin with at 8/32" when new. Check the remaining treads in the older tires and if it is less than 5/32, you may get a better deal changing all four tires changed now than doing two tires at a time. Then you have better choices of tires to pick from
     
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  20. GKL

    GKL Active Member

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    Interesting, not doubting the validity of your advice, the reason I heard in the past for your best tires to be on the front was a blowout on the front would be much more hazardous than one in the back.

    What is the specific reason for new ones going on the back ? (I need to have a very logical reason to convince my wife :D)