Pretty much sums it up . I dunno if I want to rebuild my system or go aftermarket ? My inner and outer plenums are fine . The Valve diaphram off of the top of the evaporator is toast . I think one company told me to do an upgrade . But Joe N.(nailheadina67) said that my system was a better style and rebuild it . Is there any way to test an evaporator when it's disconnected . I have a large vacuum motor from a printing press that'll "Suck Start a Harley":laugh: and a spare vacuum gauge . Could I rig up something to see if the evap. is good ? I know I'll need lines/drier/compressor . I'm considering a parallel flow condenser too . I've heard they're more efficient . Thanks , Steve
I guess Joe hasn't seen your post yet, but I can guess what he'll say. We both agree on most aspects of GM AC. Your 64 will have an STV, and yes, keep it. If the old one is damaged, replacements are available. If only the diaphragm is bad, a kit is about $10. It will need to be properly calibrated for the refrigerant that you choose, so you will probably want to have it rebuilt and calibrated. POA and STV "upgrade" kits are different, but neither one works as well as the original. You can pressure test your evaporator, but you will need accurate gauges, correct fittings, etc. It's best to remove it, clean it well, and have it tested. You would be surprised at the amount of garbage that will be on the outside of the evap. This will also let you see if there is any corrosion that may cause problems after the repair, remember, it's been in there for 44 years covered with damp dirt. If you are going to use R134a, then a parallel flow condenser is a good choice. You will have to have lines custom made though, there are no direct replacements that I know of. If you have the original lines rebuilt, you can have the rebuilder install the proper condenser fittings. I personally recommend staying with R12 on these old systems. The price has dropped drastically in the past few years. (and no need for a parallel flow condenser). If you rebuild the system right you won't have to touch it for a long time, so the price difference is negligible. Joe is a big proponent of HC refrigerants. I'll keep my opinion to myself and let him give you his input on that matter. Hope this helps.
Thanks for the input . My main concern is the vacuum cannister(diaphram) that screws in on top of the STV Valve . It's "kaput" . I need to drag out my "Hemmings Manual" ,I may have seen a rebuilding service for those somewhere in the Vendor Section. I'm sure the main diaprham in the valve is shot too . Someone hacked my switch plate at one time and put an incorrect switch in that did not actuate the small valve switch on the side of the controls that controls all functions of the blend doors,heater valve etc. Thankfully I got a new set of controls froma 65 Lark but one vacuum port is missing for the Vaccum Control on top of the STV Valve . It looks like I may be able to install my vacuum block and control on the 65 control body . I finally got a photocopied assembly manual off of ebay . Alot of the diagrams are very small and are degraded . So it' leaves me scratching my head and then get back up here to bother folks with countless questions , which I don't like to do . I feel like I'm always asking for help more than offering . Can I get your name ? Thanks again, Steve
My name is Tom. Don't feel bad about asking "too many" questions. That what forums like this are for. Just contribute what you can, I doubt anyone is keeping score. o No: If your STV is damaged, contact www.ackits.com and see if they can hook you up. Also, check out www.classicautoair.com , They offer rebuilding services. I think I just saw those vacuum control valves somewhere, but I don't remember where. I'll try to find out. I'm sure Joe will see this post eventually and chime in, and I'll help you in any way I can. Tom
Thanks , Tom . Great I need to contact them . I have them saved in my A/C folder . The hardest part is finding a shop that's got some integrity and knowledge to work on a 45 year old system . I've asked a few locally and they wouldn't even touch it . I'm in a real rural setting so I don't know many gear heads or see to many classics for that matter . Springfield , Mo. about 50 miles (A whole bunch of A/C Shops) but it would be nice finding someone with an older car that's had the work done and can recommend a good shop . Thanks very much . I'll get in here off and on for a follow up . Steve
You can do this basic A/C repair yourself, along with sending parts out to specialists to rebuild them (like STV). Replace all o-rings. Replace hoses that need it. Flush and dry.
