1963 AC evaporator core leaking?

[Mark Geertsma]

Hi all,

Again I have issues with my AC system. Had it refilled recently but within a few days the system was empty again. The AC mechanic added tracer fluid to check for leaks, but there are no visible leaks anywhere. I’m starting to think it’s the evaporator core as this is the only place that can’t be checked.

From your experience, how likely is it that the evaporator core is leaking?

And how easy (or not) is it to replace the core?

[Kurt]

It's possible that the evaporator core is leaking. There are electronic freon detectors that "sniff" the air and  beep when they detect freon (& other gasses). These are good for finding leaks from inside the A/C box through the vents. Of course if the system is empty, you'd have to put some refrigerant in1st. Worst case, the evaporator can be accessed if you take the right front wheel off. If I remember correctly, there is a panel in the wheel housing to remove for access to the evaporator core. If you still have the STV (suction throttling valve) on your system, the diaphragm tends to leak. I replaced mine a few times over the years and finally eliminated it with a modification kit. So far, so good. 

[Kenneth Barton]

Hey Mark,

I'm in the midst of converting my 63 to R134a and replacing lots of components. I replaced almost everything, including the evaporator, with new parts. And I still have been chasing leaks.

A friend brought his freon sniffer over, and the thing screamed when we pointed it at the passenger footwell and the air vents - usually a dead giveaway for an evap leak.

Frustrating considering this was a brand new unit from Auto AC Solutions in Texas.

Fortunately their service is lovely and they've sent me a new unit.

Feel free to message me to talk about AC conversions - I added a nonfactory, modern condenser and some other goodies for the Texas heat.

[Mark Geertsma]

Hi Kenneth,

How difficult was it to get to and replace the evaporator core?

I've heard something about an opening in the inner fender?

[Kenneth Barton]

Mark,

It wasn't entirely "difficult" in the sense that I never got stuck on a certain step. But it was quite involved.

I followed the procedure in the shop manual. The executive summary is you must remove the hood since the hinge blocks the evaporator case. This is best done with 3 people.

You also should take the passenger wheel off, and then the fender liner. Then everything will be fairly accessible.

I'd recommend purchasing a shop manual if you haven't already.

Good luck!

KB