1968 AC expansion valve question

[Russ S.]

Okay, the rebuild is nearing completion but I need to understand how the expanion valve bulb attaches to the evaporator tube. My bulb is straight not bent in a j-shape. It appears that either my part is not correct or in 68 not all cars had a j-shape bulb. Assuming that they should be bent where is the j-clamp attached to the tube and how is the tube routed to the valve? Any pictures available? Here is a photo of what mine looked like prior to restoration.

Russ

AC bulb.jpg

[Monte M.]

Re: 1968 AC expansion valve question

Russ,

I have most A/C parts here out of the car, but I am not sure of what it is exactly you are asking.

Here is a few pictures of an original line set. Maybe that will answer your question. If not be more specific and I will see what I can do to help.

Monte
Off 1971 C-3.jpgOff 1971.jpg
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[Dale C.]

Re: 1968 AC expansion valve question

In 68 the A/C hoses were clamped not crimped as in 69 and on.

[Tom L.]

Re: 1968 AC expansion valve question

The bulb is not a "J" shape, it should be straight. I clamaps the the suction line at the exit of the box. See your pic, the bulb is located under that black gooey insulation at the top of the pic. Good luck!

[Monte M.]

Re: 1968 AC expansion valve question

Russ,

Sorry for my earlier post. I have no idea what I was thinking at the time.

The bulb typically attaches to the straight part of the evaporator line, under the black goo as Lynn suggested.

My guess is the bulb should be straight unless there is something going on out of the ordinary.

The bulb attaches with two small clamps and screws. I will post pictures tomorrow when I get a chance.

The expansion valve in your picture looks to be original. You can tell by the length of the tube the bulb is actually on.

On an OEM expansion valve there is very little extra length in that line. On replacements there is usually enough extra line that you have to run the line round and round four or five times to make the bulb fit where it belongs.

If that is your car in the picture, or your car looks similar, you will need to get a heat gun to help get the tar tape off. I is usually very hard and brittle by now.

Once again, Sorry for posting the wrong stuff. I will post a few more pictures tomorrow.

By the way, even though you cannot see the little clamps that hold the bulb in place, if you need/want a set of originals, I have some.

I will even help you set up your A/C system if you want to. I have helped quite a few of the guys on this sight get their system back up and running.

Monte

[Terry M.]

Re: 1968 AC expansion valve question

Okay, the rebuild is nearing completion but I need to understand how the expanion valve bulb attaches to the evaporator tube. My bulb is straight not bent in a j-shape. It appears that either my part is not correct or in 68 not all cars had a j-shape bulb. Assuming that they should be bent where is the j-clamp attached to the tube and how is the tube routed to the valve? Any pictures available? Here is a photo of what mine looked like prior to restoration.

Russ

[ATTACH=CONFIG]47770[/ATTACH]

Back in the days when I used to play with AC systems I saw a number of GM OEM expansion valves (not necessarily on Corvettes, but why should Corvettes be any different?) that had a date code on one of the flats of the valve, just below the circular bellows. You might want to examine yours closely.

[Russ S.]

Re: 1968 AC expansion valve question

Here is my bulb. It is straight and had two clamps holding it on. I thought it was original but was told it should be j-shaped with a special clamp to hold it on. Thanks for the offer to help. I have had all the components rebuilt and/or tested so I hope it works when I finish it.

AC bulb.jpg

[Dick W.]

Re: 1968 AC expansion valve question

Here is my bulb. It is straight and had two clamps holding it on. I thought it was original but was told it should be j-shaped with a special clamp to hold it on. Thanks for the offer to help. I have had all the components rebuilt and/or tested so I hope it works when I finish it.

[ATTACH=CONFIG]47781[/ATTACH]

I have worked on more than a few GM A/C systems and the configuration of your looks like what I would expect to see. That valve was used by not only GM but many, if not most, aftermarket systems