Check this out , a bit in depth though. click here
>>>RENAULT LAGUNA MKII
Hope this answers some of your questions.(probably create more)
Had 2 front tyres changed today , all seemed ok till i came out of work and found the nearside flat, thought maybe a holed tyre and started to footpump it up ,went up ok ,but when i removed the air attachment air whistled out of the valve.
To cut a long story short , the guys at the tyre place tried to remove the valve cores with the key to deflate the tyre before changing.
i stepped in and said that they shouldn`t be removed.
--------TOO LATE ??
I`m guessing that they`ve knackered one up and jammed the dust cap on to get me away.
Imagine the fun I`ll have tomorrow when I return .
Please don`t make the same mistake as i did and use the back-street type garages.
the few quid i saved will now cost me big time.... i.e. new valve+programming.........doh!
One other tip :- change your dust caps to plastic ones then they won`t corrode on, I had no choice as my chrome ones were nicked ages ago!!!!