Author Topic: Troubleshooting 1967 factory air (Read 348 times)

ko67 · « **on:** June, 28, 2010, 12:32:43 PM »

I am getting ready to troubleshoot my a/c issue. The PO put in a Sanden 134a compressor and the related underhood components. The dash components are factory in dash air, and were replaced during the restoration. When Max or fresh are selected on the dash contols, the fan comes on and heated air comes out from the underdash vents. Nothing comes from the dash registers. I assume that the heat/cool air mix door vacuum motor or the vacuum switch are the culprets, but I do not know that. The compressor runs and the discharge/suction lines are appropriate temperatures for a functioning compressor. I have a vacuum gauge, but does anyone have a recommendation for how to rouble shoot this issue? I have the factory manual, but it seems to be little help. Any advice from A/C gurus on access the right bits? I will post pics of the process so that all can learn from my experiments.

Kev

Midlife · « **Reply #1 on:** June, 28, 2010, 02:04:52 PM »

I believe 1967 was the first year for vacuum assisted doors for the A/C and heater box. I'd pursue that line of investigation before futzing with the A/C units themselves.

Sluggo · « **Reply #2 on:** June, 28, 2010, 05:35:41 PM »

Quote from: Midlife on June, 28, 2010, 02:04:52 PM

I believe 1967 was the first year for vacuum assisted doors for the A/C and heater box. I'd pursue that line of investigation before futzing with the A/C units themselves.

+1

PJ Moran · « **Reply #3 on:** July, 06, 2010, 09:43:05 AM »

MANY years ago I bought a "Vacuum" manual for my '68. It has some excerpts from the shop manual plus some diagrams / drawings I've never seen anywhere else. I suggest you get one for your '67 if it's available.

My AC won't blow cold, either. It's all new and the case has been rebuilt / resealed. The AC guys tell me to check / verify proper operation of all of the vacuum motors, doors, levers, etc.

So, I pulled my seats, borrowed an electric vacuum pump, and went to town. I found no leaks. All of the "motors" work. The recirculate one operates VERY slowly as the signal to that one seems to be really weak (tried two different control heads). The only problem I found was the valve that actuates the water valve was sticking, which would make the valve stay shut, not open. This should help AC performance, not hurt it, though.

I discovered that the vacuum testing table in the shop manual does not agree with the one in the vacuum manual. The one in the vacuum manual is correct, and the one in the shop manual is wrong.

So, I'm back to finding an AC shop that actually knows what they're doing and can figure out why my AC won't blow cold.

Main point is to advise you to get one of those vacuum manuals, pull your seats, borrow a vacuum pump, get a vacuum gage, etc. and start checking things under the dash. You can use a hand pump (MityVac), but it's a royal PITA. A decent MityVac kit will come with some hose adaptors for various testing purposes.

ko67 · « **Reply #4 on:** July, 08, 2010, 05:40:48 PM »

Thanks, PJ. I appreciate the info. You will save me some time. Congrats on the COTM honor. I have business in Shreveport in a couple of weeks and may be making the run the the vert. If so, maybe I will get in touch and run by to see you if you are around.
Kev

sigtauenus · « **Reply #5 on:** July, 20, 2010, 01:03:22 PM »

This is perfect timing for this topic. I'm debating whether or not to rebuild the factory system I have or to go aftermarket such as Vintage Air or Classic Auto Air. If I had any doubts, I'm now solidly leaning towards the aftermarket kits.