I have a 1992 Accord ex that is loosing pressure in one of the tires.
I fill the tire to 28psi the next day I'm down to 24psi, next day 22psi
this continues until about 18psi and then the pressure loss seems to
stop.The tire has been removed and the mechanic says it's ok.
I have noticed there is a lot of corrosion around the rim of the wheel
next to the tire. Could this be the cause of the problem? If so, what
should I do?
BINGO! The corrosion buildup on your rims is likely the cause. I've
run into the same problem on several vehicles - all with alloy wheels.
The cure is to have the tire dealer remove the tire, remove the
corrosion with a wire brush or power wire cup brush, remount the tire
with a goodly amount of bead lube, rebalance and give it a couple years
until you have to repeat the cycle.
It's not universal, I'm told but prevalent enough with the alloy wheels
that the dealers know exactly what to do.
I've read in the newpaper's mechanic column that you need to reseal the
aluminum with a clear lacquer;that most aluminum castings are porous and
will leak air if unsealed.
It also prevents the return of the white corrosion.
Using nitrogen for the fill will further slow leakage.
I've read where more shops are now offering this.One I saw offers free
1. Proper inflation is key to improving fuel economy up to 3% whatever
used to fill
2. Nationwide fewer than 10% of tire dealers offer nitrogen but number
3. Finding way into mainstream at growing number of tire dealers including
4. Most dealers charge $2-$5/tire for initial nitrogen fill-up, generally
offer free lifetime refills
5. Improved pressure maintenance important for sensitive automatic
1. Nitrogen molecules bigger than oxygen molecules so seeps out more slowly
2. Nitrogen resists heat buildup better than air which contains moisture
3. Nitrogen reduces oxidation that can damage tire from inside out
4. Nitrogen is inert gas so no safety or environmental issues
From http://www.mfgdist.com/aircel-n2cel.htm ;
Nitrogen maintains tire pressure better.
Oxygen in air is a tire killer. Compressed air contains 78% nitrogen and
21% oxygen. Oxygen in compressed air is very aggressive and reacts
chemically with rubber causing it to lose its elasticity and strength.
Oxygen first consumes the tire liner, then ravages the insulating rubber as
it permeates through the entire casing. This deterioration is accelerated
due to the pressure difference between tire pressure and atmospheric
pressure. In testing, tires inflated with nitrogen lost only 2 psi in a
six-month period, whereas tires filled with compressed air lost six times
as much in the same period. Since nitrogen maintains tire pressure much
longer and will not react with rubber as oxygen does, tire failure is cut
dramatically. With more consistent tire pressure and improved tire
durability, handling for those larger loads is better, too, making your
drivers safer drivers.
Then the mechanic is a fool. A tire which is loosing that much air will
certainly show itself in a bubbling water test if said mechanic knows
what they are doing.
Find someone competent.
PS Yes, rim corrosion can cause air leaks at the bead and at the valve
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.