Factory A/C Issues--1964 327/300

[Bruce Boatner]

The factory A/C in my 1964 coupe that I just acquired (the car, not just the A/C) works fairly well, but I'm afraid the shop that repaired the A/C just before I bought the car employed a few shortcuts that I need to unravel. The guy I bought the car from took it to his friendly neighborhood Firestone dealership for the work, so I guess perfection cannot be expected. My first problem is that the A/C compressor runs continuously and does not cycle on and off as it should. There is vacuum line that hooks up to a fitting on the intake manifold just behind the carburetor that was plugged with a bolt. I suspect this vacuum line may be involved in the temperature control process, but I am not sure how.

Secondly, I have noticed that water accumulates on the passenger side floor board whenever I run the A/C. Probably just a tube that has been disconnected or routed wrong, but I have no idea where to look.

I would greatly appreciate any and all advice from all of you A/C experts out there. It's still A/C weather here in Houston.

[Mike M.]

Re: Factory A/C Issues--1964 327/300

The assembly manual, in the C-60 section of options, shold be of help. good luck, mike

[Geoff C.]

Re: Factory A/C Issues--1964 327/300

Sir,
On a 1964 model the vacuum fitting near the rear of the intake supplies vacuum to the Power Brakes (if PB equipped), the Automatic transmission vacuum modulator (via a convoluted metal pipe) (if Auto equipped) and the Air Condition for the STV (Suction Throttling Valve), the Hot Water shut of valve and the controlling Brass switch under the dash (if AC equipped).

See your Assembly Instruction Manual or my web site for a schematic of the AC vacuum circuit.

Geoffrey Coenen




AC Vacuum Hose Circuit

[G B.]

The compressor shouldn't cycle

Your '64 never had a cycling compressor clutch. They were introduced for automotive a.c. systems long after the last mid-year Corvette was built. The first one I saw on a Chevy product was in the mid-seventies.

[G B.]

Water on passenger carpet

Bruce, this sounds like condensation from the evaporator box that is building up and overflowing out the ductbox seams.

There is a factory drain hole in the bottom of the evaporator box just outside the firewall. It's supposed to have a short stubby drain hose on it, but most of these hoses are missing now. This hose or the hole might be plugged with mud, fungus, or an insect nest. Poke it clean. Just try not to damage the evaporator core right above it.

[John C.]

Re: The compressor shouldn't cycle

Jerry as usual is exactly correct. You regulate the amount of cooling by a damper that adjusts much air either bypasses the evaporator coil or flows through it.

Old Air Products makes a kit that can change this setup to one that cycles on and off but you'll sacrifice originality points.