Losing Pressure

[Octomonkey]

I had a set of summer tires on and shortly before I put the all-seasons back on, one of the tires was losing air, and I would have to reinflate it about once every week. I figured once I got the all-seasons back on, the problem would go away. Well, it didn't. One tire is still losing air, but not as quickly as the summer tire was. Does anyone have any idea what could be causing this?

[gto57]

If it is the same rims, probably a bent rim??

[Octomonkey]

If it is the same rims, probably a bent rim??

I could inspect it more closely, but it didn't appear to be bent anywhere the last time I looked at it.

[GTO_04]

Won't a road force balance show a bent rim?

Since it is happening with different tires, it has to be the rim IMHO.

GTO_04

[nadthomas]

Pull the wheel, inflate it to about 60psi, and either submerse it in a tub or sink if you have one big enough, or spray a soapy water mixture around the bead and look for bubbles. If you don't find a leak there, start checking the the tread area. You could have a small nail hidden in the tread, but I bet you will find the leak at the bead. I had 2 brand new tires that leaked around the bead, not because of wheel damage or dirt in the bead, but because there was a defect from the tire mold. Either way if the wheel is not bent, a tire shop can apply a sealant and remount the tire to get them to seal up better. That's what they did on my new tires (I should have pushed for them to replace the tires since they were brand new), but they are now holding air just fine.

[Jontall]

The tires have a low profile and pot-holes (when hit) can unseat the bead from the rim causing a slow leak. Break and reseal both beads.

Also:

Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) #05-03-10-003 - (Mar 31, 2005)
Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant)

with Cast Aluminum Wheels


Condition
Some customers may comment on a low tire pressure condition.

Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel.

Cause
Porosity in the cast aluminum wheel may be the cause.

Correction
Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI.
Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location.
Important:

• If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced.

• If two or more leaks are located on one wheel, the wheel should be replaced.


If air bubbles are observed, mark the location.
- If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001A or newer - Tire Puncture Repair Procedures for All Cars and Light Duty Trucks (SI Document ID #1573203).

- If the leak is located on the aluminum wheel area, continue with the next step.

Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel.
Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting (SI Document ID #1332544).
Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M® General Purpose Adhesive Cleaner, P/N 08984, or equivalent.
Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, GM P/N 12378478 (Canadian P/N 10953493) or equivalent, to the leak area.
Allow for the adhesive/sealant to dry.
Notice: Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak.

Align the inscribed mark on the tire with the valve stem on the wheel.
Mount the tire on the wheel. Refer to Tire Mounting and Dismounting (SI Document ID #1332544).
Pressurize the tire to 276 kPa (40 psi) and inspect for leaks.
Adjust tire pressure to meet the placard specification.
Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle (SI Document ID #664222).
Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI.

[J.E.T.]

Had the same issue on my chrome Beyern 5's, front ones only. Had to remove the tire, clean the rim and apply sealant........problem solved.

JET