Finding Cause of Slow Tire Leak 2001 Camry

Question

I have a 4cyl 2001 Toyota Camry

It has the following rims.

I believe they're an aluminum alloy. I have a matching set of 4 DUNLOP tires rated for 44 PSI. I'll edit this post with specifics momentarily.

They were last checked for tire pressure 2,900 miles ago, one of the tires had a staple in it which punctured the tire. This leak was plugged and the tire was filled (as were the other three tires).

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One tire looked quite low (although not so low that it was worrying me) - I decided to check the pressure and the tires were as follows.

Front-left: 30.5 PSI

Front-right: 20.5 PSI

Rear-right: 10.5 PSI (this is the one that looked low; it is also the tire which was plugged.)

Rear left - 35.9 PSI

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I topped them all off to 40 PSI on Saturday. By today [Monday] the tire which was at 10.5 PSI is already down to 35 PSI. (All other tires are fairly stable.)

My question is: what is the normal rate of air leakage for tires / alloy rims? And how can I diagnose leaks around the rims?

I will have the tire itself checked, to make sure the area surrounding the plug is not leaking (and to ensure there are no new obstructions) this weekend.

Also, 10.5 PSI is quite low, is it low enough that I should consider that tire to be damaged? What are some signs of premature wear to look for?

All four tires are brand new, they were put on the car by the previous owner before I purchased it (2,900 miles ago; give or take).

Answer 1

Sly's technique is a good one for diagnosing leaks, but you may find it difficult to spot if the leak is too small.

If you have a persistent leak on one particular wheel, it may be that there is some corrosion or foreign particle contamination on the inside of the wheel rim - this prevents the tyre from sealing properly against the rim and allows the air to slowly seep out.

Any decent tyre place should be able to take the tyre off, clean the edge of the rim and tyre and re-seat it - many now add a white 'goo' sealant to help combat this problem.

Answer 2

Easiest way to diagnose leaks is to use something like Windex. Spray it on the tire and around the rim. If you see any bubbles, that's where the air is leaking from.

Answer 3

A loss of 2-3 pounds a month is reasonable. This will vary with ambient temperature changes. If the outside temp. is 75 degrees when the tire is filled and 30 degrees when it is rechecked the loss may be more. Conversely if the tire is filled when it is 30 degrees and rechecked at 75 degrees it may be higher. Tire pressure should be checked monthly. Many low profile tires show little evidence of low pressure due to the short sidewall. When you see a statement to check the tire pressure when cold it refers to the tire being at ambient temperature, and not having been driven for several hours. To determine the extent of damage from running under inflated the tire must be removed from the rim and the interior examined for evidence of damage.

Answer 4

Unmount your tire from your car using the Jack and wrench provided, full it with air, and then put it in a large tub of water, a bath tub will work if you dont mind a tire being in it, could get messy. but just slowly put the tire in, not all the way, just enough so that one side is in, then let the water settle, see if bubbles are coming from the tire or seal, if it is then you know where your leak is. If not then rotate the tire so that a new section is in the water, and look again.