Tyres losing pressure

[robert.saunders]

Hello everyone, I am sorry if this has been posted before, but here goes...

I have encountered gradual pressure loss in my back tyres, I have the standard "Elegance SE" alloys fitted. I have had tyres checked, no sign of puncture, slow or otherwise.

My question being, are alloys subject to slow pressure release? Sorry about my ignorance but wheels and tyres are really not my thing. Anyhoo, it only seems to happen on the rear wheels, fronts seem to hold pressure. Rear tyres quite new too, only about 3 months old.

The pressure goes down about 10psi a month, which doesn't sound a lot, I don't know, but as I say, fronts maintain. Also, it seems more one tyre than the other....

Any comments as ever well received. This is honestly the best MB forum (and I'm not just saying that to get an answer!)

 

[Brian WH]

Hello everyone, I am sorry if this has been posted before, but here goes...

I have encountered gradual pressure loss in my back tyres, I have the standard "Elegance SE" alloys fitted. I have had tyres checked, no sign of puncture, slow or otherwise.

My question being, are alloys subject to slow pressure release? Sorry about my ignorance but wheels and tyres are really not my thing. Anyhoo, it only seems to happen on the rear wheels, fronts seem to hold pressure. Rear tyres quite new too, only about 3 months old.

The pressure goes down about 10psi a month, which doesn't sound a lot, I don't know, but as I say, fronts maintain. Also, it seems more one tyre than the other....

Any comments as ever well received. This is honestly the best MB forum (and I'm not just saying that to get an answer!)

Yes it is the BEST FORUM mate.

Now then, your tyres.

The clue is in the recent fitting I think. I would suggest that they were not sealed properly. I would return them to whoever fitted them and tell them the loss of 10 psi per month which is totally unacceptable and needs rectifying. The Alloys have nothing to do with it nor does the fact that they are on the rear.

Let us know how you get on.

 

[andy_k]

I'd agree with Brian

but.....

if your previous set of tyres also lost pressure it could possibly be the wheels (alloy rims can become porous with age) although this would be more likely if the alloys were older.

I'd have a good moan at the tyre fitter and get them to refit them and ensure the lips of the wheels are spotless

Andy

 

[wiggy]

heres a different slant on it, did they fit new rubber valves when they changed the tyres? could be where your problem lyes, cover them with soapy water and give em a good bend about, a pound to a piece of poo says you get bubbles.......oh bugger!!! wrong again, heres the pound......Ill get me coat!

 

[R2D2]

.........fauty valves are really common but at least they are cheaply fixed!

 

[Anders]

After checking my tyre pressure one evening, and putting a few psi in a rear tyre, I found it deflated the next morning.

Optimistically expected the worst, nail or similar, but found nothing. Checked the valve, and two out of three times it stuck open.

Check, as said above, with soapy water or a bit of spit that the valve is not slowly leaking.

 

[Tan]

I had a similar problem with Dad's car, it was the valves!

 

[Will]

Did you have this pressure loss before having the new tyres fitted, and did they fit new valves or not?!?

I would take first guess at it being the valves, as on a car as new as yours (?) you shouldn't really be getting bead leakage?

Good luck,

Will

 

[C240Sport97]

my car looses about 2 PSI a month on each of the 4 tyres .. and has done so in the 2.5 years I have had it, even with new tyres, and refurbished AMGs

 

[Shude]

One of my rear tyres lost half it's pressure nearly every day, I just topped it up whenever I went anywhere. A few months ago it decided to totally give up luckily about 30 seconds from home, and not on the motorway at 70-80mph where I was about 5 minutes before that!

 

[Brian WH]

One of my rear tyres lost half it's pressure nearly every day, I just topped it up whenever I went anywhere. A few months ago it decided to totally give up luckily about 30 seconds from home, and not on the motorway at 70-80mph where I was about 5 minutes before that!

Which is exactly why you should get them corrected if they lose pressure, as it can fail on you anytime.

Tyres should not lose "hardly any pressure" if seated and fitted properly with new valves. More than 5 psi per month and you have a problem.

 

[robert.saunders]

Update

Well, I did have a problem with one of the rear tyres before I replaced both of them.

New valves have been installed yes - so they say...

I haven't yet tested the valves (the other half has taken the car away for a few days) but I will this week and see what's what.

I know I said the fronts maintain; I guess in reality they lose a couple of psi per month but I live with that.

I did think (for some reason) that alloys, being porous, would result in some pressure leakage but perhaps the couple of psi per month is just that.

Anyway, depending on the valve test I will get back to the fitters...