62 Cutlass Convert

I am on my 4th heater valve rebuild by Old Air for my 62 Cutlass. Looked at my history on rebuilds and I’m getting 6-10 months out of a valve and it starts to leak at the diaphragm. VERY unhappy.

I am using Evans waterless antifreeze which has worked out well and has good characteristics for alum…This is the alum V8 model.

In talking with the Evans tech on the problem he said they may be using old timey rubber on the diaphragms. He said Evans is not compatible with genuine rubber.

Old Air says yes they are using rubber diaphragms that they have made for them.

Anyone using Evans?

And if so has anyone experienced this?

Tedd Thompson

Well, If Evans says not to use natural rubber with their product and your rebuiler says they use natural rubber my suggestion is find a builder that doesn't use natural rubber or change your fluid that is compatible with natural rubber. I'm running a Ranco valve that has been rebuilt for the last 10 years and have no problems. I have no idea what rubber was used in it's rebuild and I use old world Prestone fluid as my antifreeze so someway you need to get the correct combo.....Tedd

62 Cutlass Convert

Yeah i know i have 3 options.
1 Change to a rebuilder with modern compund for the diaphram. Talked to 3 so far and all use rubber.
2. Adapt a modern valve to the application. Not desired but not that big a deal
3. get another rebuild in rubber and switch to classic green. Like the Evans for the Aluminum eng and radiator, doesnt require changing every two years, cost etc but this maybe the only good solution available.

My post was to see if anyone else is using Evans and has had a similar experience or knows a rebuilder who uses a modern compound?