Search found 32 matches

by pete_89t2
Thu Jul 22, 2021 5:49 am
Forum: Automotive Air Conditioning Forum
Topic: Underwhelming cooling performance after complete A/C restoration
Replies: 11
Views: 7373

Re: Underwhelming cooling performance after complete A/C restoration

Cooling systems where the bypass runs through the heater core should not be blocked with a single valve. There are 4 port / 2 way coolant valves in many newer cars that can be used to keep the hot water out of the passenger compartment. Both vacuum and electric operation units have been used by For...
by pete_89t2
Wed Jul 21, 2021 5:10 pm
Forum: Automotive Air Conditioning Forum
Topic: Underwhelming cooling performance after complete A/C restoration
Replies: 11
Views: 7373

Re: Underwhelming cooling performance after complete A/C restoration

The 35psi low side indicates a refrigerant Temperature around 40f So I would suspect reheating or air bypassing the evaporator with vents nearly 20 degrees warmer. ^You may be on to something here. This afternoon I took the car out for some tuning pulls on the freeway; ambient temps in the mid-80's...
by pete_89t2
Wed Jul 21, 2021 12:05 pm
Forum: Automotive Air Conditioning Forum
Topic: Underwhelming cooling performance after complete A/C restoration
Replies: 11
Views: 7373

Re: Underwhelming cooling performance after complete A/C restoration

At these conditions what is the temperature of the suction line (evap out going to compressor)? I didn't actually measure the temperature there, but the aluminum bead lock fitting where the suction line connects to the evaporator was cold to the touch - not quite freezing cold, to the point where i...
by pete_89t2
Wed Jul 21, 2021 7:33 am
Forum: Automotive Air Conditioning Forum
Topic: Underwhelming cooling performance after complete A/C restoration
Replies: 11
Views: 7373

Underwhelming cooling performance after complete A/C restoration

Greetings, I recently completed the A/C restoration on my '93 Mazda RX7 project car, and finally got around to charging the new system with R134A. Bottom line is the cooling performance is rather weak - coldest it would get at the blower vents was 15*C (59*F) on a humid day with 86*F temps. Looking ...
by pete_89t2
Sun Jan 24, 2021 8:57 am
Forum: Automotive Air Conditioning Forum
Topic: AC restoration questions, '93 Mazda RX7
Replies: 32
Views: 30502

Re: AC restoration questions, '93 Mazda RX7

Another update & question. I got that discharge pipe fitting welded, and it no longer leaks from there. But the system still won't maintain a vacuum for more than an hour or so - vacuum drops from 30 inHg to about 25~26 inHg in that time. A very slow leak, so I put a partial charge of refrigeran...
by pete_89t2
Fri Jan 22, 2021 8:27 pm
Forum: Automotive Air Conditioning Forum
Topic: Help with refrigerant
Replies: 3
Views: 3872

Re: Help with refrigerant

I got a 64 Impala with an aftermarket AC system put in, the car has been non operating for 30 years. The AC system is all setup but the compressor was removed about 20 years ago and the hoses that were connected to it are still there but exposed to the moisture and oxygen for a long time . So my qu...
by pete_89t2
Mon Jan 11, 2021 5:46 am
Forum: Automotive Air Conditioning Forum
Topic: AC restoration questions, '93 Mazda RX7
Replies: 32
Views: 30502

Re: AC restoration questions, '93 Mazda RX7

Techniques for a gas-tight seal is to ensure that you heat the parts and not the brazing rod so that the rod material flows smoothly into the heated joint. Typically, the parts need to be heated to around 700 degrees F, which depends on the melting point of the brazing rod you're using. Check the p...
by pete_89t2
Sun Jan 10, 2021 8:04 am
Forum: Automotive Air Conditioning Forum
Topic: AC restoration questions, '93 Mazda RX7
Replies: 32
Views: 30502

Re: AC restoration questions, '93 Mazda RX7

Well I managed to get an electronic leak detector and found my leak yesterday - it was the brazed joint I made between the male O-ring fitting and the pictured compressor fitting pipe, discharge side. Heck, once I added some refrigerant, I didn't need the sniffer to find the leak - the compressor lu...
by pete_89t2
Sat Jan 09, 2021 6:45 am
Forum: Automotive Air Conditioning Forum
Topic: AC restoration questions, '93 Mazda RX7
Replies: 32
Views: 30502

Re: AC restoration questions, '93 Mazda RX7

Another update. My local Advance Auto parts didn't have a manifold gauge set available yesterday, so I couldn't use it verify the readings I got from my questionable Harbor Freight gauges. But I had a thought - can I self-test my Harbor Freight gauge set to see if it holds vacuum on its own, without...
by pete_89t2
Fri Jan 08, 2021 6:34 am
Forum: Automotive Air Conditioning Forum
Topic: AC restoration questions, '93 Mazda RX7
Replies: 32
Views: 30502

Re: AC restoration questions, '93 Mazda RX7

Al9 wrote:Orings have to be lubed (with a non-hygroscopic AC lube/AC o-ring lube, such as the good ol' mineral, and Ester, unfortunately, is hygroscopic).
I purchased the proper O-ring lube along with all the fittings & O-rings and used it, so that's not an issue here.