Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Slow leak in driver's side's rear tire

I drove my pickup for the first time since February. The left front tire had 26 psi (should have 29); the right front had 23.5; the right rear had 29 (should have 35), the left rear had 10.5. I inflated them to correct pressure in February (probably a little over), so the left rear lost about a .1 psi/daily. It took air, and kept it for the short drive I took. Any suggestions for what I should look at first?

A shop should be able to find the source of the leak, or if the tires need replacement now is the time. My work truck had a slow leak, ended up being a staple, one air bubble maybe every 30 seconds, I got new tires but I did not have to pay for them,

That’ll sometimes happen when a vehicle sits for a long time.

Temperature effects wheels/tires.

Keep an eye on the tire pressures. And if the tires keep losing pressure, it’s time to dip them into the dunk tank to locate the leaks


Sometimes that sort of a leak will fix itself if you keep the tires properly inflated going forward. Check them once every few weeks and top them off is probably the best advice, as it might fix it with no further bother. Beyond that, you can check the valve stem seal by inflating the tire by putting some soapy water on the end of the stem, see if any bubbles form. If you don’t have valve caps on all the tires, get some b/c dirt can get to the seal area for the little pin thing and cause a slow leak. If you notice a leak, sometimes you can fix it by tightening that pin with a special tool. If you’re up for removing the wheel, clean it off first, and brush it with soapy warm water using a paint brush. Lay the tire horizontally and use a long bubble level and shims to get the wheel as horizontal as possible, then check the bead area with the soapy water technique. I had a bead leak on one of my truck’s tires this past summer which showed up w/that method.

Its getting colder now so I’d top them off again and check weekly. If one is still losing air, mix up some dish washing detergent and spread it over the tire-treads, rims, valve stem, and look for a bubble forming. One slow leak I finally had to put a large container of water and wait a little to see a bubble once every 30 seconds or so. For a couple years I was losing air in my trailer tire at maybe 30 # a year. Finally I noticed a small nail in it and was pretty well sealing the leak, except not entirely. It was time to replace it anyway.

Fill your tires with nitrogen . With nitrogen, your tire pressures will remain more constant, saving you a small amount in fuel and tire-maintenance costs. There will be less moisture inside your tires, meaning less corrosion on your wheels. You will not be able to feel any difference in the ride or handling or braking, unless your tire pressures were seriously out of spec and changing to nitrogen brought them back to the proper numbers.

I fill them with 79% nitrogen now. I’ve been thinking about switching to helium for the savings from the added buoyancy.

I remembered that in 2009 this same tire was really low (7 psi). I replaced it with the spare, filled my bathtub, couldn’t find a leak (but did get my tub and myself really dirty). I took it to a llantero who figured out the valve was bad (he had a deeper tub). Because I brought the tire in myself he installed a new valve for $3 (!). I put that tire in the spare tire mount (under the bed). Isn’t this an odd coincidence? The valves on the other 3 tires haven’t failed.


Consider switching to hydrogen, it will give you even more lift :slight_smile:

1 Like

Do YOU do that that?

Where do you get your cylinder filled/refilled?

To be honest, I have no intention of filling my tires with nitrogen

I just want to know how you do it, since you brought it up :crazy_face:

I tried that with my Hindenburg.


Nitrogen has been used in race cars tires for years because of its ability to remain stable in all weather condition. Since 2000,dealerships, tire shops and service stations offers this service for regular passenger vehicule.for a few dollar per tire. Cars equipped with tire pressure monitors will also benefit from this service.

I was not very good at chemistry but believe @RandomTroll is correct that regular air already has a high proportion of nitrogen in it.

Paying extra for Nitrogen on a non - race car vehicle is silly. And I really don’t think the tire pressure sensors really care.

deleted . . .

STUPID 10 character minimum

What’s your angle?

It sounds like you’re heavily promoting filling tires with nitrogen

For “regular passenger vehicles” I don’t see a meaningful advantage

Ive heard that that race cars that use nitrogen have two tire valves, so that the pure nitrogen entering the tire can push the existing air out the other side. Road cars only have one valve. How do you get the existing air out when you fill a road car tire with nitrogen?

I was always interested in the same thing: how do they purge the air from tires when claiming to fill it with nitrogen?
I can imagine that repetitive fill&drain cycles will eventually get most of oxygen content out, not sure how many cycles they do

A vacuum is pulled on the tire to remove any air before filling with nitrogen.

Much like how a vacuum is pulled on an AC system before it’s filled.


1 Like

This is how they do it:

I didn’t ask how “they” do it

I asked how YOU do it