I purchased my car with a non-working a/c and have used it for several years that way. I decided to fix it, and replaced the entire system except the evaporator and the compressor. All new hoses. I flushed the evaporator with a pressurized flush can, and blew it out with compressed air. I flushed the compressor by filling and draining it with PAG-46 several times, probably 8oz total. I added 4oz of PAG-46 to the compressor, and 2oz each to the condenser and evaporator. I pulled 30" of vacuum on it for 30 min, then let it sit an additional 30 min to verify no leak. I then charged the system with 36oz of r134a.
Problem, the a/c works, but isn't very cold. Driving for several hours today in 90 degree heat, it was livable in the car, but probably never got below 75* with the a/c on full.
When I charged the system, the high side pressure went to 250 psi as soon as there was sufficient r134a to keep the clutch locked, and the low side pressure ended up right around 50 psi with the 36oz charge. The high side maintained the 250 during the entire charging process and a few minutes afterwards till i took the gauge set off. Ambient temp was 80-85 degrees. I didn't have a thermometer to measure vent temp, but i would guess 50 degrees or so. I have a crown vic PI electric fan, very similar to the mark VIII unit, and it kicks on low when the a/c is on.
I'm assuming I either overcharged due to the smaller plate/fin condenser, or I have a bad compressor. However, I'm certainly not an a/c expert, so I may be way off here. Any help is appreciated. I can get more precise temp and pressure measurements if needed.
Thanks,
Chris
What kind of setup did you use to pull the vacuum then charge the ac system? Sorry about how long this is, I tried to shorten it. Scroll to the bottom
[TABLE="class: fluid-capacities"]
[TR]
[TH="class: fluid-capacities-year"]Year[/TH]
[TH="class: fluid-capacities-model"]Model[/TH]
[TH="class: fluid-capacities-refrigerant, colspan: 2"]Refrigerant[/TH]
[TH="class: fluid-capacities-oil, colspan: 2"]Oil[/TH]
[/TR]
[TR]
[TH="class: fluid-capacities-refrigerant-type"]Type[/TH]
[TH="class: fluid-capacities-refrigerant-ounces"]Ounces[/TH]
[TH="class: fluid-capacities-oil-type"]Type[/TH]
[TH="class: fluid-capacities-oil-ounces"]Ounces[/TH]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] ASPIRE[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 1997[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 26.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1994-1996[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 25.00[/TD]
[TD] PAG 46[/TD]
[TD] 6.00[/TD]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] CONTOUR[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 1995-2000[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 26.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] CROWN VICTORIA[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 1997-2004[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 38.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.50[/TD]
[/TR]
[TR]
[TD] 1995-1996[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 38.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1994[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 34.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1993[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 38.00[/TD]
[TD] Mineral[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1992[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 36.00[/TD]
[TD] Mineral[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1989-1991[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 48.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1988[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 52.00[/TD]
[TD] Mineral[/TD]
[TD] 13.00[/TD]
[/TR]
[TR]
[TD] 1987[/TD]
[TD] All Engines To 9/86 ...[/TD]
[TD] R12[/TD]
[TD] 52.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] All Engines From 9/86 ...[/TD]
[TD] R12[/TD]
[TD] 52.00[/TD]
[TD] Mineral[/TD]
[TD] 13.00[/TD]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] ESCORT[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 1997-2002[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 28.00[/TD]
[TD] PAG 46[/TD]
[TD] 6.75[/TD]
[/TR]
[TR]
[TD] 1994-1996[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 28.00[/TD]
[TD] PAG 46[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1993[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 34.08[/TD]
[TD] Mineral[/TD]
[TD] 7.75[/TD]
[/TR]
[TR]
[TD] 1991-1992[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 33.92[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1988-1990[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 36.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1987[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 41.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1986[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 36.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] FESTIVA[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 1988-1993[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 25.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] FOCUS[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 2000-2004[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 26.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] LTD[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 1986[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1985[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] MUSTANG[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 1997-2004[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 34.00[/TD]
[TD] PAG 46[/TD]
[TD] 8.50[/TD]
[/TR]
[TR]
[TD] 1994-1996[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 34.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1989-1993[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1986-1988[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] PROBE[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 1997[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 28.00[/TD]
[TD] PAG 100[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1994-1996[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 28.00[/TD]
[TD] PAG 100[/TD]
[TD] 6.75[/TD]
[/TR]
[TR]
[TD] 1993[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 28.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1989-1992[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] TAURUS[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 1996-2004[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 34.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1995[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 32.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1994[/TD]
[TD] Excl. SHO ...[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 33.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] SHO ...[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 33.00[/TD]
[TD] PAG 46[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1993[/TD]
[TD] SHO ...[/TD]
[TD] R12[/TD]
[TD] 32.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] Excl. SHO ...[/TD]
[TD] R12[/TD]
[TD] 32.00[/TD]
[TD] Mineral[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1992[/TD]
[TD] Excl. SHO ...[/TD]
[TD] R12[/TD]
[TD] 41.00[/TD]
[TD] Mineral[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] SHO ...[/TD]
[TD] R12[/TD]
[TD] 41.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1991[/TD]
[TD] 4 Cyl. 2.5 Eng. ..[/TD]
[TD] R12[/TD]
[TD] 41.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 6 Cyl. Excl. SHO ...[/TD]
[TD] R12[/TD]
[TD] 41.00[/TD]
[TD] Mineral[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 6 Cyl. SHO ...[/TD]
[TD] R12[/TD]
[TD] 41.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1990[/TD]
[TD] 4 Cyl. 2.5 Eng. ..[/TD]
[TD] R12[/TD]
[TD] 41.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 6 Cyl. Excl. SHO ...[/TD]
[TD] R12[/TD]
[TD] 41.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 6 Cyl. SHO ...[/TD]
[TD] R12[/TD]
[TD] 41.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1989[/TD]
[TD] 4 Cyl. 2.5 Eng. ..[/TD]
[TD] R12[/TD]
[TD] 44.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 6 Cyl. Excl. SHO ...[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 6 Cyl. SHO ...[/TD]
[TD] R12[/TD]
[TD] 44.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1988[/TD]
[TD] 6 Cyl. 3.0 Eng. ..[/TD]
[TD] R12[/TD]
[TD] 44.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 6 Cyl. 3.8 Eng. ..[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1987[/TD]
[TD] 4 Cyl. 2.5 Eng. ..[/TD]
[TD] R12[/TD]
[TD] 44.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 6 Cyl. 3.0 Eng. ..[/TD]
[TD] R12[/TD]
[TD] 44.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1986[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 44.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] TEMPO[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 1994[/TD]
[TD] 4 Cyl. 2.3 Eng. ..[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 33.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 6 Cyl. 3.0 Eng. ..[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 33.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1992-1993[/TD]
[TD] 4 Cyl. 2.3 Eng. ..[/TD]
[TD] R12[/TD]
[TD] 36.00[/TD]
[TD] Mineral[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 6 Cyl. 3.0 Eng. ..[/TD]
[TD] R12[/TD]
[TD] 36.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1989-1991[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 36.00[/TD]
[TD] Mineral[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1987-1988[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 36.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1986[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 36.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR]
[TD] 1985[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 41.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR="class: fluid-capacities-model"]
[TD][/TD]
[TD] THUNDERBIRD[/TD]
[TD="colspan: 4"][/TD]
[/TR]
[TR]
[TD] 2002-2004[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 28.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1995-1997[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 36.00[/TD]
[TD] PAG 46[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1994[/TD]
[TD] All Engines[/TD]
[TD] R134a (http://"http://www.techchoiceparts.com/inventory/116589")[/TD]
[TD] 36.00[/TD]
[TD] PAG 46[/TD]
[TD] 6.75[/TD]
[/TR]
[TR]
[TD] 1989-1993[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 7.00[/TD]
[/TR]
[TR]
[TD] 1988[/TD]
[TD] 4 Cyl. ..[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 6 Cyl. ..[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] 8 Cyl. ..[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR]
[TD] 1987[/TD]
[TD] All Engines[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[TR]
[TD] 1986[/TD]
[TD] All Engines To 1/86 ...[/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 10.00[/TD]
[/TR]
[TR]
[TD][/TD]
[TD] All Engines From 1/86 ... [/TD]
[TD] R12[/TD]
[TD] 40.00[/TD]
[TD] Mineral[/TD]
[TD] 8.00[/TD]
[/TR]
[/TABLE]
Verify the orifice tube.
A new orifice tube would have been in the low side (liquid) line.
I assume you replaced the accumulator? I pulled a vacuum on my system for 1hr to ensure all the moisture was boiled out. Also used a vent thermometer as I was charging system. As soon as the center vent showed 40F I stopped the charge. I had about half of a 12 oz AC can remaining for a total charge of about 30oz. If the system capacity is 40oz and the rule is to charge no more than 80% for a 134a conversion that would be about 32oz max. Don't know if a few ounces would make a difference but my AC is frosty with the outside temp near 100F. I also used SubZero brand 134a freon with the ICE additive available from AutoZone and NAPA for about $21.99 each.
One more thing...make sure the schrader valves in the service connectors are tight to prevent leakage.
Sticker on core support showed 42oz of r12, so 36oz of r134a is close to the 85%. Probably lost a bit from the 12oz cans due to residual and line purges, so should be very close.
EDIT: just reread, I thought it was 85%, not 80%. I can bleed some off, but would an ounce or two too much cause it to be this inefficient?
New fixed orifice tube in liquid line.
Schrader valves are tight.
New accumulator with hose.
Used a gauge manifold set and a 3 cfm vacuum pump designed for auto a/c work.
EDIT AGAIN: When I let the system hold vacuum, the gauge was rock solid. I read that it would creep down a bit if there was still moisture in the system, so i believe any present had boiled off.
Think that covers everything.
Thanks,
Chris
Verify clutch fan operation. Poor airflow through the condenser will cause high pressures
Your pressures are to high. As chicken points both the loew and the high side are way to high. What size is or should i say what color is the TUBE!!! That is number one. Then you have to cool down the condenser to get that temp down by at least 50*. With 50 on the low side you are just wasting good freon. You need 30- 40 PSIG on the low side or the ball game is OVER!! By the way always use reformulated RA134A. There is still some old stuff hanging around as i am told and i actually find that hard to believe but that is the word on the street. Never use BLENDS. Good luck
Clutch fan was deleted after it blew up and destroyed everything in the front of the engine bay. Is now a very large two speed electric fan, which turns on low with the a/c. Holding my hand in front of the condenser while charging showed good air flow.
The orifice tube is one of the built in units, not a separate tube like modern systems. This one: http://www.oreillyauto.com/site/c/detail/MRY0/55602/02728.oap?year=1987&make=Ford&model=Thunderbird&vi=1140253&ck=Search_a%21s%21c+orifice+tube_1140253_1550&keyword=a%21s%21c+orifice+tube
I thought the pressures seemed too high, but the high side went to 250 psi as soon as there was enough r134a in the system to engage the compressor clutch, less than a 12oz can. It then held steady while the low side increased with added refrigerant.
As for the coolant, i ordered a case of 12oz cans of johnson's 134a. It is not a blend, I'll bring in a can later to check if its ra134a.
Thanks,
Chris
Tom, this is the 134a I used: http://www.johnsens.com/index.php/products/detail/6312-r-134a
Just hooked up the manifold gauge set again to verify info.
Ambient temp is 84.
Car was sitting in the sun before and while tested
System showed 100psi with engine off.
Low side went to 50psi when engine started
High side went to 260psi, then dropped to 235-240 psi when car idled down.
Thanks,
Chris
That is good freon and a good supplier. Your numbers are off the charts and way to HIGH on both sides. Try this make sure you do not have to much freon in the system or just do this. Run the system at 1200 RPM with the AC on of course. Then with a garden hose on light mist spray the condenser while watching the low and high side readings. If both numbers FALL and they WILL. Check the vent temp at the center outlet and post the numbers. It should be around 35-40* Good luck!!
Ok, i just went out and tried it.
It is now dark out and 75 degrees ambient.
Had a friend rev up the car to around 1200 rpm (no tac)
Pressure was 30psi low, 150psi high
Spraying water on condenser didn't change it
I couldn't find my laser thermometer, but the vent felt quite cold, probably 40 or below.
Thanks,
Chris
How long did you let it run? If you're fighting a hot condenser condition, you need to give it time to get plenty hot before you start taking measurements and/or spraying the condenser.
Tried it again today with hotter conditions and direct sunlight
84* ambient and humid
Started up car, got 275 high, 50 low
Had a friend rev the engine to somewhere near 1200 rpm, and ran a gentle stream of cold water back and forth across the condenser
Pressures dropped to 175 high, 26 low
Vent temps measured with a blue point probe thermometer stuck in the central vent, 47.2 stable.
I'm wondering if thats indicative of a blend door or debris clogged evaporator? Along with an overcharge?
Thanks,
Chris
No, it's indicative of a problem with your cooling fan. Your best choice is an electric fan, but it might be enough to start with is you make sure you have a good fan clutch.
I have replaced the clutch fan with a very large electric. It turns on low with the a/c, and is pulling a good amount of air through the condenser.
Also, it doesn't cool well while cruising at 75mph, so doesn't sound like a fan issue to me.
I'm wondering about the blend door/clogged evap as the vent temp seems far too high for the pressures.
Chris
However, when you used water to cool the condenser, the vent temp dropped right in, as well as the pressures. You have a hot condenser. Now we figure out why.
You wouldn't happen to have a TC nose, would you?
You wouldn't happen to have a TC nose, would you?
Also, what HVAC system do you have, auto or manual?
No tc nose, manual hvac.
Cooling the condenser dropped the pressures, but not the vent temps significantly. Vent temps at 250/50 were in the mid 50's
Chris
You have to remember that your vent temp will always be approximately equal to the low side pressure. Hot condenser-high low side pressure-high vent temp. Causality.
But with the low side at 26psi, the vent temp was 47.2. Doesn't seem to be correct. Hense my wondering about blend door or evap issues.
Chris
Clearly you figured out by now you either have a TUBE that is to small or a condenser as well. Along with not enough air across it. When you got the 30 On the low you got cold air discharge from the vents. So the tube may be to small and or the condenser as well. 50 on the low is NO DAM GOOD. With that pressure you are way to HIGH for proper cooling. Better check that TUBE and hose assembly for application. Sounds like the tube is to small. You need around .060-.070 Tube to work correctly. I knoe it is built in to the hose but clearly you are not FLASHING OFF IN THE EVAPORATOR. Your charge is still to high. You need to dump and if by dumping your numbers come down and cooling does not improve you need a bigger tube or condenser!!
Ok, fair enough. How much do i need to dump? As in try to drop the low side down to 30-35 at 85 degrees?
Thanks,
Chris
YES YES YES. I am not saying that will work because i am not there in person. But whenever a system is close to 48-50 LBS in 85-90* you are dead in the water. Just look at the charts. And i know it is normal some times to have over 200. But once you approach over 200 You are at the max point. Normal readings at or around 1200 RPM should be 30-35 On the LOW and 200-230 On the high in 95* Just saying. Other wise you wont cool down> GOOD LUCK.
Check the gauge reading compared to evaporator DISCHARGE CHART. Just run down the number where you low side is and it tells you YOUR DISCHARGE TEMP. @50 You are blowing 54* and that SUCKS. You need APP 40* at the center vent to cool a car in 100* weather Good luck
http://www.csgnetwork.com/r134apresstempconv.html
Well, it was 70 and raining all day today. Next time its warm and sunny i'll "recover" some of the freon and see what the vent temps do.
Thanks,
Chris
Ok, it was 88 and sunny today, so I lowered the system pressure some. Was at around 35 low at idle, but when i revved it, it dropped to 28, so i may have removed too much. Vent temps were in the mid 40's, so that was much better. I'm done with it till i drive it somewhere on a warm day and see how it preforms.
What should i set the low cycling switch at? I believe i've read 22psi for r134a.
Thanks,
Chris
Lower the switch to around 24-26 LBS. When you got the 35 on the low side you are golden. Revving will always send the low side down a bit. This is normal and i bet you AC is working much better. You are GUILTY OF ONE OF THE BIGGEST MISTAKES AMATEURS MAKE WITH AC SYSTEMS. YOU OVER CHARGED IT. Run it for a while and i think you are OK NOW. Good Job!!
NOTE you were flooding the evaporator with to high a charge. Your gauges told you that!!!
Here is a simple technique to get the most out of a 134A conversion. I followed this method on several r12 cars. The newer vehicles are computer controlled so it won't work. The old Ford system used r12 and a cycle on off switch depending on the low side pressure.
Here's the technique it's real simple. First I assume everything is in good working order. System has been flushed, proper oil, good compressor, evaporator and condenser and orifice tube and accumulator. Forget about the cycle switch all you need to do is bypass so that the compressor is either on or off. Throw that switch away. You'll need a good digital thermometer. Put that in your air vent. Measure the temperature as you add Freon.
Proceed slowly all the time watching the temperature coming out of the air vent. When you get to the lowest temperature it will start to rise. Stop filling the system at this point. You may only need a can or two of Freon.
If you've ever watched the frost on the lines you'll notice that it will move. By that I mean the line may be frozen but as you add more Freon it will melt and start to sweat. What you want to do is find this sweat point (move it) so that it falls on the evaporator core. When it does you're getting the coldest temperature possible out of your vent. Also you evaporator core will not freeze up. There is no need to cycle. Furthermore your pressures are lower, putting less strain on the compressor.
Using this technique I get about a 20 – 25° difference between ambient and inside vent temperature. Needless to say the air works better than new. You’re basically operating on perhaps a third to half capacity but there is no need to cycle, your compressor is on all the time but with reduced pressure and less strain and your evaporator core will not freeze.