Rear Tyres Losing Pressure Faster Than The Fronts

[tufty9]

I have noticed ever since I had new Pirelli Scorpion tyres put on the rear of my 2003 3 door RAV several months ago(There are Bridgestones on the front) that the rear tyre's seem to lose pressure a lot quicker than the fronts. If I pump all tyres up to 29Psi, then within a month the 2 rear Pirelli's are down to 26Psi or less whereas the Bridgstone's on the front stay at 29Psi for months without losing pressure. Is it normal for the rear tyres to lose pressure this quick? I'm new to owning a car, and my boyfriend used to deal with the tyre's but he can't remember whether the Toyo Tranpath tyres which were on the rears lost pressure that fast!

So I'm wondering if it's normal, and if not, could it be Pirelli's are not a good make, or could it be the place that fitted them used naff valves? If it's the valves are they easy to get a garage to replace, or are they actually attached to the tyres? Sorry for sounding such a dunce, but the tyre issue has been bugging me for ages! Car is having service soon, so if it's something that can be fixed I will mention it to them!

I hope the solution is not gonna be expensive!

[john1944]

I have noticed ever since I had new Pirelli Scorpion tyres put on the rear of my 2003 3 door RAV several months ago(There are Bridgestones on the front) that the rear tyre's seem to lose pressure a lot quicker than the fronts. If I pump all tyres up to 29Psi, then within a month the 2 rear Pirelli's are down to 26Psi or less whereas the Bridgstone's on the front stay at 29Psi for months without losing pressure. Is it normal for the rear tyres to lose pressure this quick? I'm new to owning a car, and my boyfriend used to deal with the tyre's but he can't remember whether the Toyo Tranpath tyres which were on the rears lost pressure that fast!

So I'm wondering if it's normal, and if not, could it be Pirelli's are not a good make, or could it be the place that fitted them used naff valves? If it's the valves are they easy to get a garage to replace, or are they actually attached to the tyres? Sorry for sounding such a dunce, but the tyre issue has been bugging me for ages! Car is having service soon, so if it's something that can be fixed I will mention it to them!

I hope the solution is not gonna be expensive!

It is always recommended to chck tyre pressures every week, and if you are loosing just 3 lbs pressure over a month, I do not think that is too bad. One other point is part of the car in direct sunlight when you check the pressures, because this can throw out readings considerably. Try putting 31 lbs in the rear tyres, this will help lengthen your periodic checks.

[tufty9]

No the car isn't in sunlight, in fact it's normally dark when I've checked them lately. It just seems odd why the rears lose pressure and the fronts don't.

[bothwell_buyer]

Funny one!

I must admit that I don't check the tyre pressures regularly at all - I tend to look at them and know. When driving, I will also know if a tyre is soft from the way the car handles - but then I've had the car for almost 15 years.

You can easily check the valves by putting some soapy water on the end of the valve and if bubbles appear then the valve is leaking. Normally, a valve is replaced when a new tyre is fitted - but not always!

There are new systems available which monitor your tyre pressure - I think Hoovie on this forum fitted a set. The new RAVs have them fitted too I think.

The only time I've had problems with tyre pressure going down that fast was due to slow punctures. A garage or tyre shop can test your tyre/wheel to see if theres a leak by putting the whole thing in a bath of water to watch for bubbles= air escaping.

So as a summary, to me, losing that air is not normal over a 1 month period. I've got 3 sets of tyres and wheels and not one wheel loses that pressure over even 6 months. None of the tyres are Pirellis right enough, but I can't see them being much different....

[anchorman]

I think you'll find they are leaking around the beads or valve stems. I would take it back and they normally have a tank they can dunk them in to test for leaks.

Don't let them charge you for resealing.

[bluemarky]

Hi

I've had problems with alloy wheels before that were leaking at the rim, when i had the tyres taken off i found that a certain tyre group did not check the inside of the rim for corrosion so when they fitted the tyres the seal did not seal properly thus resulting in the tyre losing pressure over a time, tool car back to tyre centre and they took tyres off and cleaned the inside of the rim with a grind stone to get a good seal, then i had no problems.

This is a common problem with alloys

mark

[jedi134]

Try swapping the rears for the fronts and see if the same happens. :)

[bitman]

not very wise to have different tires on a permanent 4x4 box...

i know nothing to do with losing pressure what will be mostly the cause of corroded rims since those toyota / lexus allows are very likely to corrode.

[Hoovie]

I have noticed since having a TMPS system installed that after driving, the pressures on the right-hand side are about 10% higher then the left, and the front are about 10% higher then the rear,

And also as John mentioned, the sunlight - and air temp - can make a major difference - upto 20%, but the pressures while varying over a day and driving should end up being the same every day if you are checking the PSI same time each evening if not driven within the last hour or so.

in your situation, sounds to me totally like leaking and I personally reckon a car tyre should loose NO pressure over many, many months, let alone 3psi each month

[bothwell_buyer]

Ah furgot - ma landrover suffered air loss but it was the wheels that were well corroded....... a set of new wheels fixed the air loss, and fitted new tyres at the same time - shame the lump has been off the road since whilst another engine is sourced that actually starts when you want it to !! :censor: :censor: