Evans antifreeze and heater valve

[62cutlassconvert]

I am on my 4th heater valve rebuild by Old Air. 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…

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?

[62cutlassconvert]

Hi Joe,

I saw an old post of yours that you adapted a valve from Napa to replace your orig.

That’s probably my best option.

Do you have a picture of the install and possible a part number?

Thanks
Layne

[62cutlassconvert]

No one?

[graytoad]

I just saw your post. I was wondering about waterless antifreeze and any possible issues. We had our heater core redone bu Fusicks: I better check with them about that now! Heater cores seem to be my enemy. Every car we have restored – if we did not do the heater core too: sure as shooting the darn thing would start leaking a year or so later.
Other than that: how do you like the waterless antifreeze? We are just about to re-install the engine in our car after having it rebuilt.

[62cutlassconvert]

Should be no problem with the heater core. Problem is the heater valve.

Sorry to say Fusick uses rubber for the diaphragm. I talked to Terry in the back who does their valve rebuilds. Everyone i checked with uses rubber. According to Terry and the Evans guy Dexcool and other modern antifreezes with Similar corrosion Resistance chemicals also have a problem with rubber. Modern hoses are not rubber, they are modern compounds so you don’t see a problem there.

The good news is in talking this out with Evans and then Terry, Terry agreed that a modern “rubber” like Viton is resistant and in checking it out Terry said they will work up a Viton diaphragm. It will cost slightly more for a rebuild with the Viton diaphragm, maybe ~$20. Hopes to offer it beginning of 2021.

Since i already have Evans in the system I will pop for one. My valve has the capillary tube clipped so replacement is simple. On the other hand if your engine is installed and the valve has the tube it’s a lot of work to change it with the engine in the car.

The Evans works very well. I run a 180 Degree high flow Robert Shaw type thermostat from Stewart Eng with a small bleed hole in it. Usually run a temp below thermostat Rating. Don’t know if it was a fault of the Evans, which is less viscous than standard antifreeze, but i had a hell of a time clearing what i believe was an air pocket on my system. Had a running hot problem for a while On the new engine which suddenly solved itself. Had some of what i believe were contributing issues which i wont go into here.
Like the corrosion protection and not having to change it every 2 years. If you loose some you need to re-top with Evans or you loose the benefit. Its pricey, but you don’t have to change it.

I run Classic Green in my other cars mainly because they already had a std antifreeze in them and
To change you need to flush with an Evans prep product and completely eliminate any water and then fill with Evans.

[62cutlassconvert]

Fusick has now had produced and tested a Viton diaphragm that is resistant to the Evans and other antifreeze like Dexcool with additives corrosive to the commonly used rubber diaphragms.
Doing one for me now. Be glad to have a heater back.

[BruceM]

Hi, I’ve been able to rebuild the heater valve myself and it seems to have worked fairly well. NAPA sells the diaphragm for about 10 bucks. It is part no. BK 6601000. You just have to pry the tabs away from the back and separate the parts, remove the old valve, clean up the pieces (I bead blast them), then I put some spray on gasket sealant and put in the new valve and put the pieces back together again as tightly as possible. Haven’t had a problem. Anyway, maybe I don’t understand your problem? Let me know and maybe I can help.

Bruce

[62cutlassconvert]

Hi,

The problem is not rebuilding the valve or getting the diaphragm, please read up to the earlier posts for the issue.

Also, I understand there is a stem seal that should be replaced behind the diaphragm. Were you able to get that?

[BruceM]

Sorry, I guess I’m not much help. I haven’t had a negative experience due to the antifreeze used, and I haven’t used the Evans type. If I learn of something on this problem, I’ll post.

Bruce

[62cutlassconvert]

Received my new Viton diaphragm valve and have installed. Hope this is the last one!

The also pulled off the end of the valve tube and replaced the stem seal in there. I don’t believe Old Air went that far.

Terrance at Fusick as very helpful.

Thanks for all the comments.

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