Help me find this tire leak
 

One of my tires loses about 1 pound of air every couple of days. However, the leak stops leaking at 25psi. I have removed the tire thinking there is nail or something causing a slow leak. Nothing.

Could it be the valve itself? Anyone else here with this experience?

Could be the valve and also the rim..

I had a similar problem on my 1971 W113 280SL.
Checked the tire for leaks in a tub of water, removed and remounted the tire, installed a new metal valve and still a slow leak down to about 22-24lbs..
Ended up putting in a tube and no more problems !

Lay the tire flat and slowly pour some water around the bead area. The water will collect and fill the low spot at the tire/wheel interface and enable you to spot any bubbles.

Can also be the valve stem or the core.

Jim

Charge the tyre with air conditioning fluid then use a sniffer or an ultraviolet light. See

http://www.justoffbase.co.uk/Air-Conditioning-Leak-Detection-Kit-Sealey-VS600

also see Adixen.co.uk maybe for some ideas.

Normal engineering crack detection techniques, so called

- dye penetrant

or

- ultrasonic scanning

around the rim.


I know it is very hard to fine small leaks. There was man on Ebay selling a wheel that was replaced by the MB dealer. He/they eventually found the crack in the rim; welded it and was selling the wheel.

Loose valve might be worth checking, but i'm betting on it being a slight bead seal leak. JimFreeh's method is the best check, adding a little dish soap to the water will make it even more visible (and fun for kids!!). While you have the soapy water out, brush a little onto the valve stem and valve.

Good luck.

rim
 

If you can get the tire off, use steel wool to clean off the rim where the tire bead seats. You should also clean the tire bead with the steel wool. Then, reinflate and reseat with soapy water on the bead.

x2 on the valve stem and/or seal

Errrr....This seems:

- cost prohibitive
- potentially illegal depending on refrigerant
- not very logical

How about using soapy water? Any tiny leak will bubble up if the water has soap in it.

Yep soapy water is good if you can't immerse the whole wheel.

It will certainly show any problems if you fill the op of the valve stem.

If the valve is leaking and it is a Schrader valve (http://en.wikipedia.org/wiki/Schrader_valve) don't over tighten the valve. You might get one of those prong shaped security bits to fit (see http://www.peachparts.com/shopforum/showpost.php?p=2715799&postcount=17 for the type of thing I mean)

First, overpressure the tire (50? psi). Then throw soapy water over the whole tire to look for bubbles. I've been able to find the smallest of leaks using this method.

In my area tires often develop rim leaks from corrosion. Lay the tire flat and throw soapy water on the rim. Wait a number of minutes and the slow leaks will show up as small patches of foam.