There have been several cases reported, in the UK, of corroded alloys on post 2004 Prius. Various causes have been suggested including corrosion from brake dust to poor lacquer to seal the wheels. I would be interested to know if this problem exists on the US cars as Toyota seems to be taking forever to sort out what is an incredibly simple problem. Come to think of it Lexus has the same problems too. It's not often anyone can say that Toyotas have a problem, but it's doubly irritating that all the other manufacturers seem to perform better than Toyota on this issue. Stuart S :angry:
Stuart, you have a different size and possibly make of wheels on your UK Prius. I have never heard of any corrosion problem with US/CAN wheels.
I haven't heard anything specific about the Prius or Toyota cars, but alloy rims in general have problems with corrosion. Aluminum is a soft, highly reactive metal. What keeps it from fizzing away almost immediately is that Aluminum oxide is very tough (chrome works the same way). The outside layer of the wheel oxidizes into a tough, corrosion resistantent layer. If you scrape off that layer, or prevent it from forming, then the Aluminum underneath is exposed to corrosion. That's the problem with sealing Aluminum with a coating: the coating prevents oxygen from getting to the top layer of Aluminum, so no hard oxide layer forms. If you can keep out all of the oxygen (you won't), then you are okay, but what really happens is oxygen gets in through very small holes. This oxygen starts crevice corrosion, which eats away under the coating. It is common to have trouble with rim leaks on older alloy wheels, especially if tires have been remounted a few times. Tom
I have filiform corrosion starting on 2 wheels at the edge of the center holes. Later this summer I'll probably polish it out and re coat with clear.
Alloy wheel corrosion is a common problem here. Anyplace you have road salt in winter, the clear coated wheel can't keep it out. I solved the problem - sort of - by running winter tires on steel wheels in winter. The alloys stay in the heated condo storage unit.
---------- I haven't heard anything specific about the Prius or Toyota cars, but alloy rims in general have problems with corrosion. Aluminum is a soft, highly reactive metal. What keeps it from fizzing away almost immediately is that Aluminum oxide is very tough (chrome works the same way). The outside layer of the wheel oxidizes into a tough, corrosion resistantent layer. If you scrape off that layer, or prevent it from forming, then the Aluminum underneath is exposed to corrosion. That's the problem with sealing Aluminum with a coating: the coating prevents oxygen from getting to the top layer of Aluminum, so no hard oxide layer forms. If you can keep out all of the oxygen (you won't), then you are okay, but what really happens is oxygen gets in through very small holes. This oxygen starts crevice corrosion, which eats away under the coating. It is common to have trouble with rim leaks on older alloy wheels, especially if tires have been remounted a few times. Tom[/quote] ------ Hello, We have a 2007 Prius. It was mentioned: "I have filiform corrosion starting on 2 wheels at the edge of the center holes. Later this summer I'll probably polish it out and re coat with clear". Could you tell me what the name of the "clear" product is?Thank you Read more: http://priuschat.com/threads/corroded-alloys.19350/#ixzz25Jf3szVd" I haven't heard anything specific about the Prius or Toyota cars, but alloy rims in general have problems with corrosion. Aluminum is a soft, highly reactive metal. What keeps it from fizzing away almost immediately is that Aluminum oxide is very tough (chrome works the same way). The outside layer of the wheel oxidizes into a tough, corrosion resistantent layer. If you scrape off that layer, or prevent it from forming, then the Aluminum underneath is exposed to corrosion. That's the problem with sealing Aluminum with a coating: the coating prevents oxygen from getting to the top layer of Aluminum, so no hard oxide layer forms. If you can keep out all of the oxygen (you won't), then you are okay, but what really happens is oxygen gets in through very small holes. This oxygen starts crevice corrosion, which eats away under the coating. It is common to have trouble with rim leaks on older alloy wheels, especially if tires have been remounted a few times. Tom[/quote]
