14 replies to this topic

[fenghuang]

I've had this Mini a few months and it's only been used a couple of times a month so far. In that time 3 of the tyres have lost a significant amount of pressure - enough to be visibly in need of pumping.

I reckon the odds of 3 slow punctures is pretty slim.
So is this most likely to be old tyres in need of replacement, poor fitting, or just some thing that small wheels are more prone to?

[Kieranlee999]

i think it might just be a mini thing mine do the same what type of wheels? 

[Miniminx71]

Tyres will lose more pressure in cold weather, and they may have been inflated when the tyres were warm which would have given an inaccurate reading. Pump them back up from cold and see what happens.

 

 

If in any doubt, most tyre garages will do a tyre check for a few pounds.

Edited by Miniminx71, 19 February 2015 - 11:17 PM.

[1984mini25]

If there isn't any visible punctures (nails/screws etc.) and the tyres are heavily cracking, it could be the valves (hence why they are changed when new tyres are fitted) or more likely corrosion between the bead of the tyre and the rim. Easy way to check is to mix up some soapy water in a bottle of some sorts, remove the wheel, lay flat and pour the soapy water round the bead/rim of the tyre, with any noticeable bubbles indicating an air leak.

 

Few possible fixes if the rim is leaking, you can have the bead popped and sealant applied and the tyre reflated. The tyre removed and the bead of the rim cleaned, repainted and the tyre refitted. The tyre removed, wheel stripped, repainted/ refinished etc. or to replace both the wheel/s and tyres for new.

[Wiggywithahailo]

Had this once before with an old Ford with metal rims the bead was rusty flattened it off...no more leaks

[lsto]

One of my wheels has had a slow puncture for over a year now. Been to 2 different tyre shops and they both cleaned up the bead and changed the valve, to no avail. Can't find any leaks with soapy water and a bucket. I just resigned myself to pumping it up every 2 weeks

[fenghuang]

... what type of wheels? 

12" Minilites. The fact that I think they've been reconditioned makes me wonder whether the bead is indeed the problem.

Tyres will lose more pressure in cold weather, and they may have been inflated when the tyres were warm.

There's far more pressure getting lost and over too long a period of time for this.

[pierres]

Had this problem what they do is take the tyre of clean inner rim put a sealing compound on and refit tyre and job done have not had any problem since, that was about six months ago

[Craig89]

This was happening to a wheel of mine recently, suspected the bead but once the wheel was removed there was a very small nail in the tyre. Had the puncture repaired and now, touch wood, all good

[spiguy]

With alloys which will now be fairly old, it's most likely leaking at the bead to rim seal. With alloys corrosion is an additive process, ie it makes the surface where the corrosion occurs increase in size, rather than getting a dip or pit like with steel. As a result the bead is moved away slightly from the rim causing potential for a leak. I have had this eventually on all my alloys, including one of the current ones.

 

The best cure is to take the tyre off, rub down the corrosion until it is very smooth and then paint with something like silver enamel paint, or any sort of paint really. This will keep it at bay for another few years until it happens again. I believe that garage tyre inflation equipment is a bit of a culprit in this as there is often moisture in the air line. I try to avoid using garage inflation equipment, but if I do need to I usually operate the air line against the side of the tyre, you will see the moisture wetting the tyre, and after a few seconds it will dry up. Then without releasing the trigger I put it on the valve, and inflate the tyre. Regular use of forecourt inflation is likely to put a reasonable amount of water in there which will speed up the corrosion process.

 

As mentioned above by others, some soapy water sprayed around the rim will show up any leaks.

[megamini_jb]

As already said, most likely the bead seal. That's where I'd try first.

I had 2 wheels leaking there, bought myself some bead sealer from ebay and done it myself, 3 months on and no pressure lose in either.

Edited by megamini_jb, 20 February 2015 - 09:57 AM.

[1984mini25]

 I believe that garage tyre inflation equipment is a bit of a culprit in this as there is often moisture in the air line....

 

It's probably more down to the camps on the tyre machine and a ham fisted approach chipping off bits of paint that over time allow moisture in and corrosion to start. That an knock on wheel weighs, witch due to there design can also chip the paint of the rim.

[gazza82]

My pet hate .. knock-on balance weights on alloys .. why the h3ll did they bother to invent stick-on weights!!

 

You also get a build-up of rubber around the rim over time which they should clean off .. but if you aren't there to watch them they do take short cuts ...

[AVV IT]

As mentioned above, old alloys often corrode underneath the tyre bead which then causes air leaks. Standard Rover minilites are notorious for this. To check take the offending wheel off and immerse it in a childs paddling pool (or the bath if yer missus won't hit the roof). Slowly rotate the wheel and look for air bubbles, from the rim, the valve or the tyre itself. It's much like looking for a puncture on a bicycle inner tube, but on a larger scale.

If you get air bubbles appearing around the rim, then it's a case of having the tyre removed, and removing the offending corrosion, before repainting and refitting the tyre. Take a look at this wheel refurb thread I did a while back, that shows pics of the corrosion I had under the tyre bead of some leaking miniltes, (and the paddling pool technique too).

http://www.theminifo...rb#entry2596269

[spiguy]

 

 I believe that garage tyre inflation equipment is a bit of a culprit in this as there is often moisture in the air line....

 

It's probably more down to the camps on the tyre machine and a ham fisted approach chipping off bits of paint that over time allow moisture in and corrosion to start. That an knock on wheel weighs, witch due to there design can also chip the paint of the rim.

 

Indeed, but next time you use an air line, blast it at your tyre and watch the water spread over the rubber.