Ian C Posted July 25, 2009 Share Posted July 25, 2009 So, I get my new Rays wheels a couple of years ago, and almost instantly while parked at my parents someone nicks two of the valve caps. Shiny anodised blue aluminium they were too. So me being me I just buy a pack of Halfods boggo silver ones and stick two on the fronts while moving the remaining blue ones to the rear. Now I find that the bladdy steel halfords ones have corroded on to the aluminium valve stems due to the miracle of that electrical charge thing between two different metal types (can't recall the term - electrolysis? Surely not). Anyway I now can't get them off, even with pliers the whole valve rotates in the wheel rim. Sigh. So I intend on very carefully dremelling the caps in half while avoiding the thread on the stems. Fun! If anyone else has a better idea, feel free to contribute. I'm only posting this because I've not talked about my own car for ages -Ian PS I've had most of the paintwork redone to clear up a shedload of stonechips and shocker - no more decals on the door for me Quote Link to comment Share on other sites More sharing options...
Scott Posted July 25, 2009 Share Posted July 25, 2009 Can you get a hold of the stem of the valve with a set of pliers? I had this a few years back. I used mole grips on the stem and pliers on the end. If the worst comes to the worst, cut it off and get it replaced. Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 25, 2009 Author Share Posted July 25, 2009 Can you get a hold of the stem of the valve with a set of pliers? I had this a few years back. I used mole grips on the stem and pliers on the end. If the worst comes to the worst, cut it off and get it replaced. Alas, I did think of the dual grippy thing approach, but that'll probably damage the shiny blueness of the stem, plus there is a chance a minor slip with pliers will damage the lovely Rays alloy as well. So it's still Dremel winning the race for me Quote Link to comment Share on other sites More sharing options...
Scott Posted July 25, 2009 Share Posted July 25, 2009 Alas, I did think of the dual grippy thing approach, but that'll probably damage the shiny blueness of the stem, plus there is a chance a minor slip with pliers will damage the lovely Rays alloy as well. So it's still Dremel winning the race for me Ahh yes, i see your dilema now Is it possible to buy the valve's? I would still go with dual grips, cept i would cover the valve with a cloth or something like that. We use pliars with wipes all the time, all you have to be careful of is crushing. Hopefully a little bit more grip is all that you would require though. Have you tried a little heat? Quote Link to comment Share on other sites More sharing options...
Hermit Posted July 25, 2009 Share Posted July 25, 2009 They'll be on a pushbike now then Can't think of anything better than a dremel, but one thought - would it help to slice the top off the cap first so you can see better? (To avoid damaging the threads). Quote Link to comment Share on other sites More sharing options...
kieren1234 Posted July 25, 2009 Share Posted July 25, 2009 Ian, would heating the valve cap gently with something like a lighter, blow torch on low setting help at all. As the different metals will expand at different temperatures, this should free up the threads hopefully. Quote Link to comment Share on other sites More sharing options...
Homer Posted July 25, 2009 Share Posted July 25, 2009 Ian, would heating the valve cap gently with something like a lighter, blow torch on low setting help at all. As the different metals will expand at different temperatures, this should free up the threads hopefully. There's a rubber insert in the valve so you can't heat them. Personally I'd just buy some replacement valves and caps from t'net and give your local tyre place a tenner to swap them over. Quote Link to comment Share on other sites More sharing options...
TRACIE_LOU Posted July 25, 2009 Share Posted July 25, 2009 i had this problem with cheapo valve caps i had to dremel mine off too, make sure you place a thick rag around the area just incase the dremel slips off dont want a nasty sratch on the wheels, just take your time do a little at a time i found once i got close to the thread they came off by hand, have fun Quote Link to comment Share on other sites More sharing options...
merckx Posted July 25, 2009 Share Posted July 25, 2009 (edited) due to the miracle of that electrical charge thing between two different metal types (can't recall the term - electrolysis? Surely not). Galvanic corrosion, it's one of the few things that I remember from twenty years ago when I studied such things. Edited July 25, 2009 by merckx (see edit history) Quote Link to comment Share on other sites More sharing options...
stevie_b Posted July 25, 2009 Share Posted July 25, 2009 I too would suggest a 2-plier approach as Scott said. I'd wrap any nice metal bits in a thick rubber band, which will protect them from the pliers and may also help the pliers grip. Could you use a cloth to protect the wheels from damage, or would it get in the way too much? Or, instead of heating the joint, you could cool it right down with ice. You'd be taking a gamble that the difference in metal contraction works in your favour though. Quote Link to comment Share on other sites More sharing options...
supra dan Posted July 25, 2009 Share Posted July 25, 2009 i had this problem too dremel is the answer Quote Link to comment Share on other sites More sharing options...
absz Posted July 25, 2009 Share Posted July 25, 2009 can of rust off spray (freeze spray) normally does the trick with dis-similar metals. Quote Link to comment Share on other sites More sharing options...
paul mac Posted July 25, 2009 Share Posted July 25, 2009 park the car with the cap on the wheel facing down and give it a blast with WD40 and leave over night, if its facing down the rocket fuel will stay put and work its magic Quote Link to comment Share on other sites More sharing options...
dangerous brain Posted July 25, 2009 Share Posted July 25, 2009 Its called dissimilar metal corrosion in my industry and we use JC5A to stop it commonly known as yaksh*t. If you want the caps back just get the tyre place to cut the valve out from the inside of the wheel and stick the cap (I assume its a hex head cap) in a protected jaw vice and get a decent gripper moleys on the valve stem or drill a hole in the metal part and stick a drill bit through the stem to turn it. YOu may require some wd40 penetrating oil to loosen it up a bit. Spot of WD40 wouldn't hurt the on car removal either. Quote Link to comment Share on other sites More sharing options...
snake Posted July 26, 2009 Share Posted July 26, 2009 The same thing happened to mine,i snapped a valve off trying to undo one of them on my volk alloys.I just bought a new set of flush fit valves and had them changed. Quote Link to comment Share on other sites More sharing options...
Digsy Posted July 26, 2009 Share Posted July 26, 2009 Can a mod move this to technical? The freeze spray idea might work, as because the as ali is inside the steel cap, it will contract much faster than the steel (hence heating them up would only make things worse, even if it were possible). Freezing might open up a gap between the two. I would imagine that freeze spray wouldn't hurt the valve innards, either. Quote Link to comment Share on other sites More sharing options...
dr_jekyll Posted July 26, 2009 Share Posted July 26, 2009 why not take it to a tyre place so they can push the tyre back off the rim and you can remove the whole valve and replace it or put it in a vice to remove the halfrauds cap Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 26, 2009 Author Share Posted July 26, 2009 An excellent set of responses, thank you Putting cloth around the wheel when Dremelling is a good idea that for some reason hadn't occured to me yet. Usually that sort of idea crops up just after the "tzzzt" noise. The valve caps that are stuck on are the crappy Halfrods ones that cost like £3 for all 4, so I'm not destroying the Rays shiny anodised valves or paying a garage to pull the tyres off without being able to lower the pressure first in order to save them Snapping the valve sounds like a bad idea as well so that counts out gruntwork with pliers (plus I can see myself damaging a wheel easily that way!) I'm still going to go for the Dremel microsurgery first (now with added cloth!), although the freeze spray idea sounds intriguing. Galvanic reaction, thank you -Ian Quote Link to comment Share on other sites More sharing options...
paul mac Posted July 26, 2009 Share Posted July 26, 2009 if your going with the Dremel grinding discs make sure you wear eye protection, i had one fly apart a while ago and a bit ended up embeded in the insulation in the garage roof Quote Link to comment Share on other sites More sharing options...
AndrewOW Posted July 26, 2009 Share Posted July 26, 2009 My ex's wheels did this exact thing. She took it to a local tyre place, and they cut the valves off, which allowed the tyres to deflate, then replaced the valves and started again. Cheap, easy and no damage to the wheels, but I'm sure you know what you're doing though Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 26, 2009 Author Share Posted July 26, 2009 if your going with the Dremel grinding discs make sure you wear eye protection, i had one fly apart a while ago and a bit ended up embeded in the insulation in the garage roof Yep cheers mate, I wear eye protection for drilling and sanding, never mind grinding! I had a close call while shooting one day when I got part of a bullet come back at me and lodge in my cheek about 1" under my left eye Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 26, 2009 Share Posted July 26, 2009 Ian, would heating the valve cap gently with something like a lighter, blow torch on low setting help at all. As the different metals will expand at different temperatures, this should free up the threads hopefully. Aluminium alloy expands more than mild steel, so they'd become tighter. Good old pull through rubber valves with black plastic caps, Lovely jubbly Quote Link to comment Share on other sites More sharing options...
ivan Posted July 26, 2009 Share Posted July 26, 2009 Next time fit crappy black plastic covers until that 'special day' when you want to show the car off. Quote Link to comment Share on other sites More sharing options...
gavin.starr Posted July 26, 2009 Share Posted July 26, 2009 Next time fit crappy black plastic covers until that 'special day' when you want to show the car off. the chavs round my end nick them too im fed up of buying new caps now Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 26, 2009 Author Share Posted July 26, 2009 I have sourced new anodised ally valve caps. Black. Set of four. ripspeed, to my shame. -Ian Quote Link to comment Share on other sites More sharing options...
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