C2 67 A/C Question

[Terry S.]

The problem is the length of the capillary tubes on an original expansion valve for a 67 Corvette.

First I bought an original Frigidaire expansion valve with the straight probe (for passenger cars) but the length of the tube was too short to reach the top arch of the tube as per the 67 AIM. I talked to the guy who sold it to me and he said he has the correct expansion valve for a 67 Corvette with the "J" hook end but the probe capillary tube is the same length as the straight probe expansion valve and wouldn't be long enough. As you can see by my attached picture the tube, because of where it begins on the expansion valve and some twist and turns, needs to be about 18" long. The other capillary tube that goes to the POA has to be at least 11"-12" again because of twists and turns.

I believe according to the 67 AIM we are attaching the expansion valve at the correct location on the bracket that is attached to the box(from the factory) and that we have the POA attached correctly.


Any help in solving this problem would be greatly appreciated!

[Peter L.]

Re: C2 67 A/C Question

Terry - Idid not note a P/N for the VALVE ASSY, thermostatic expansion in the C60 Section of my 1967 Corvette AIM, but the October 1966 Chevrolet Parts and Accessory Catalog show P/N 5910489 in Group Number 9.213 for 63-67 Corvette. P/N 5910489 was changed to P/N 5910613 in 10-68. My 1972 Corvette P & A, Rev 9-71 lists the 5910613 for 63-67 Corvette only. 1968 -1972 Corvette calls for P/N 5910767.

The 1966 Chevrolet P&A does not show any other application of P/N 5910489 to and other Chevrolet vehicles. I have another 1975 or so Chev Pass, Chevelle, Chevy, and Camaro P&A and it does not list P/N 5910613 for any of these vehicles from 1965 to 1973.

I measured the capillaries on an original thermostatic expansion valve assy from a 67 Corvette and the capillary from the top of the valve to the top of the hooks is ~17-1/2" long and the other capillary running from the underside of the valve to the end of the fitting is ~ 13-3/4".

The P/N 5910613 thermostatic expansion valve assy corresponding capillaries are ~17-1/4" and 15-1/4" in length.

So, the bottomline from what I can tell is Corvette thermostatic expansion valve assy is unique to the Corvette C60 system and any other Chevrolet vehicle C60 thermostatic expansion valve assy most likely won't easily adapt to your 67 Corvette application.

FYI, Long Island Corvette Supply does list a replacement. Perhaps someone has had experience with it.

Hope this info helps and good luck.

Pete

[Joe R.]

Re: C2 67 A/C Question

Hi Terry:

I have a 67 A/C car so I went out to garage tonight and measured the dimension you show in your photo. It matches what you show, with about 15 linear inches from where the tube would exit the expansion valve to the top of the large pipe exiting the evaporator.

On my car, which has its original expansion valve, there is very little extra length available on the expansion valve capillary tube. The capillary tube makes a 90 degree turn as it comes out of the expansion valve, and then shoots straight up the side of the evaporator housing. The J-shaped bulb wraps around the top of the exit pipe bend and has the capillary tube entering straight in from underneath.

In other words, part of the distance that has to be covered is made up by the straight portion of the bulb. So, if you measured it on the bench, the length of the capillary tube itself would likley be about 14 inches.

By the way, in my parts collection I have an incorrect, used expansion valve has the straight bulb. I measured that tonight and it is about 14 inches from the expansion valve to the far tip of the bulb. It *might* be possible to strap that bulb to the pipe immediately above the POA valve, which would be functional but not correct in appearance.

I do not know if there is an aftermarket expansion valve that has the correct J-shaped bulb, but you can check with Classic Auto Air in Florida or Old Air in Texas. Used originals are fairly rare, and I have only seen one on ebay during the past year or so. To make matters worse, these valves are generally not rebuildable, so if you buy a used one there is some chance that won't be useable.

Hopefully the J-shaped one that your supplier says he has will turn out to be the correct size and will be functional.

Good luck with this.