Chrome plated valve stem caps

[Cadillac Tech]

#08-03-10-005A: Use of Chrome or Chrome Plated Steel Valve Caps on Aluminum Valve Stems - (Mar 31, 2009)

Subject:Use of Chrome or Chrome Plated Steel Valve Caps on Aluminum Valve Stems​

Models:2010 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn)

2010 and Prior HUMMER H2, H3
2009 and Prior Saab 9-7X​

This bulletin is being revised to include the 2010 model year. Please discard Corporate Bulletin Number 08-03-10-005 (Section 03 -- Suspension).
This bulletin is being issued to inform dealers about the use of chrome or chrome-plated steel valve caps on aluminum valve systems.
Dealers/customers cannot install a chrome or chrome-plated steel valve cap on an aluminum valve system. If this happens, the contact between the different metals results in galvanic corrosion, which will seize the cap to the stem and may fracture the stem when attempting to remove the cap.
Inform customers of corrosion issues when chrome or chrome-plated steel valve caps are used on aluminum valve stems.
Use only plastic or aluminum caps with aluminum valve systems.​

 

[XLR ED]

I just had a 04 Vette at work that needed 4 tires and it had chrome valve caps on it. One of them rusted fast to the valve stem and I had to replace a valve sensor.

 

[monepit]

And if they do seize, do not try to force it off. It is easier to go to the tire shop and let them do it. That way if, when it breaks you don't have to remove the tire and haul it in. Expierance talking.

 

[XLRJIM]

Interesting

I have had chrome plated caps on the tires for several years with out a problem. They are not magnetic so perhaps the base metal in them is aluminum also so there is no electrolysis. Just took them off this morning and there is no evidence of corrosion.

 

[monepit]

When I first bought trixie I had 2 that were seized. Two weeks ago while checking air pressure in all the cars I had 2 on the truck seized. This time I took it to the tire shop and the tried it. They broke 2. Incidentally, The reason I was checking all the cars is that I drove Windi's BMW one day. I went to the gym after work and when I came out I noticed one of the ties was low. So I took it to the shop about 3 miles down the road to air it up. When the tried to put air in it it just blew. It was off the rim on the inside. These are fancy after market rims with low profile tires, 20 inch, like Trixies. They are not run flats but I was able to drive to the shop without any damage and surprisingly, It drove like a low tire but not bad. They reseated the tire and aired it up and it has been fine ever since. I couldn't believe I was able to drive a non run flat with no air in it and not do any damage. Believe me I wouldn't have moved it if I thought it didnt have any air in it and was off the rim on the inside.

 

[Cadillac Tech]

#08-03-10-005A: Use of Chrome or Chrome Plated Steel Valve Caps on Aluminum Valve Stems - (Mar 31, 2009)

Subject:Use of Chrome or Chrome Plated Steel Valve Caps on Aluminum Valve Stems​

Models:2010 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn)

2010 and Prior HUMMER H2, H3

2009 and Prior Saab 9-7X​

This bulletin is being revised to include the 2010 model year. Please discard Corporate Bulletin Number 08-03-10-005 (Section 03 -- Suspension).
This bulletin is being issued to inform dealers about the use of chrome or chrome-plated steel valve caps on aluminum valve systems.
Dealers/customers cannot install a chrome or chrome-plated steel valve cap on an aluminum valve system. If this happens, the contact between the different metals results in galvanic corrosion, which will seize the cap to the stem and may fracture the stem when attempting to remove the cap.
Inform customers of corrosion issues when chrome or chrome-plated steel valve caps are used on aluminum valve stems.

Use only plastic or aluminum caps with aluminum valve systems.​

If you apply a little anti-seize to the valve stem threads it will help keep the chrome caps from seizing to the valve stem.