A/C Delivery Pressure

[James Matteu]

I want to know if anything can be done to increase my A/C Compressor Delivery Pressure. I just installed it yesterday. I have approximately 20-21oz. of R134A with roughly 130mL of PAG100 running a new compressor. I want to be sure this performance is not a result of the conditions I have placed on the compressor. Thank you for your time and any information you have.

 

The Performance Test Results:

 

The performance test I ran is the one found in the Helms manual. I stick one thermometer in the center vent, one in the blower intake, put gauges on the high and low side of the compressor, look up the relative humidity and find the acceptable ranges by going +/- 10% of the relative humidity.

 

Relative Humidity: 43%

Intake Temperature: 90° F

Delivery Temperature: 58° F, s/b between 53° F and 61° F, result: GOOD

Intake Pressure: 35.5psi, s/b between 34.5psi and 40psi, result: GOOD

Delivery Pressure: 174psi, s/b between 273psi and 300psi, result: POOR

 

 

 

The Story:

I just installed the compressor yesterday, and this makes the second Chinese compressor in 4 years. The last one was also weak from the start, I cannot recall the figures Honda gave me, but the tech advised me that it was weak and had a noisy clutch. The clutch eventually failed just over a week ago. I opted to try a new compressor, not one from eBay like last time. And I wanted one with a warranty. I figured I would go with something American made/rebuilt or at least Japanese. The best I could come up with for the least amount of money (not Honda) was Factory Air by 4 Seasons, a division of Standard Motor Products, Inc. According to Standard Motor Products’ website, they have a 4 Seasons manufacturing facility in Grapevine, TX. I figured this was my best shot at getting something made here in the US. I ordered a TRSA090 from Advanced Auto for $281.99, it comes with a 2 year warranty with the condition that I buy a new Dryer and Expansion Valve from them at the same time. The parts had to be ordered and I had to drive for over a week in this sweltering Florida heat before I got my compressor in the car yesterday. To my dismay, the compressor came in a box with “Made in United States” printed on it, but a sticker beneath with “Made in China” written below 4 Season’s Lewisville, TX Corporate Office and Distribution Center address. I opened it and found a Chinese compressor made by Bao Lai Enterprises International, model ATRS090. I said, “Oh boy, here we go again.” The guy asked what the problem was, I let him know that somebody put a Chinese compressor in my box and that I would not be happy if I had to use the warranty after a few weeks of use; he had no comment.

 

Other relevant information:

during installation of the compressor/dryer/expansion-valve I drained some of the old PAG100 oil for inspection. In all areas, the oil was/is in new condition. The new compressor came dry, I added roughly 130mL of new PAG100 and primed the scroll by turning the compressor by hand for about 10min. I also conditioned the oil seals by tilting the compressor on its ends for a few minutes.

 

A little internet research finds several Chinese companies making Sanden clones, they all claim something along the lines of this quote:

 

Compatible to SANDEN TRS090 with different OEM No. Left rotation for Honda Civic and more vehicle all over the world. We provide both Brand New and Rebuilt products with the quality as good as the Sanden Original Model. OEM , ODM are very welcome

 

Quality as good as Sanden, I think not.

 

 

 

 

Troubleshooting my “new” compressor:

 

Field Coil: After installation, I found the compressor would not kick on. After some testing, I found zero volts at the Field Coil ground. I tried to pull off the positive bullet connector to see if the coil even had any windings (like maybe someone used a counterfeit coil with all resin and no copper), but the wire slipped out from under the connector. It was obvious that when the coil was being “Made in China” the worker forgot to unsheathe the wire before crimping the bullet connector on it. I drove for another day in the heat before deciding it would be easier to fix it myself than to pull it out and return it for another compressor which would surely have to be ordered; i.e. more waiting, more heat. So this morning I used the bullet connector from my failed compressor clutch and soldered it onto my “new” one. After my repair, the compressor clutch was able to initialize with the clutch relay, as it should.

 

Pulley: I noticed the pulley bearings seemed noisy, I figured I had cheap bearings like before, but after re-adjusting the belt tension the noise went away.

 

Expansion Valve: After charging the system, I noticed my Expansion Valve made a high pitched whine as it tried to close. I found a TSB for a Dodge Neon saying the R134A pressure should be reduced to cure noisy expansion valves. I tried venting some refrigerant since I initially charged 24oz. and Helms states the maximum capacity is 21.1oz. to 22.9oz. By lowing the Intake Pressure from 45psi to 35psi, I made the noise go away.

 

Then the performance test…

 

Relative Humidity: 43%

Intake Temperature: 90° F

 

Delivery Temperature: 58° F, s/b between 53° F and 61° F, result: GOOD

Intake Pressure: 35.5psi, s/b between 34.5psi and 40psi, result: GOOD

Delivery Pressure: 174psi, s/b between 273psi and 300psi, result: POOR

 

I have to say, 58° F feels good, but I am almost certain that 53° F would feel even better. Thank you for reading and I thank you in advance for any and all input you have.

 

 

[Turtlehead]

Hey James. Did you vaccum the system to boil out the moisture in the air that was introduced while the system was open? To test the air temp you should set the dial to the dash vents, the outter side vents should be closed and the air should be on recirculation not enternal source. Hold the RPM's up near 2,500. If you are getting in the mid to low 50's then you are where you should be for your generation (they aren't the best). If you have the original condensor in the car you may want to change that out. The internal ports start to clog and reduce the efficiency. I will talk with my buddy at the shop who specializes in A/C and run by what you are describing and see what he can provide (although I think I know what he will say). Your high presure side does seem a little low but not that bad. The fact that you are getting to 58 degrees at that pressure may be an indication that your system is working very effeiciently and not that there is a problem (good PAG oil at the right amount makes a BIG difference and it appears you might have nailed it). You can add a little more R134 to run up the low side near 40, but I would not touch it. Try test the air temp as described above. I'll get back to you when I can.

 

They weren't putting cabin air filters on the V6's by chance? I don't recall but I don't think so, but if you have one and it is dirty change it.

 

 

[James Matteu]

The first time around, I did vacuum the system, but only for about 2 minutes. I still have the original condensor, I have contemplated replacing it but decided that it may not be necessary given the system's current performance level, i.e. clogged condensor lines lead to elevated High side pressures. No cabin filters, I wish. I had to spend about 30 minutes (being careful not to damage the fins) clearing debris from the Evaporator core.

 

Yesterday, I vented all refrigerant. Then, I replaced the Evaporator Insulators since they had melted from my spraying Lysol on them (that happened before I learned the right way to clear the drain line). I pulled 28 in-Hg for 30 minutes. Then, I recharged the system with approx. 23 oz. of R134A. With doors and windows closed, the system still only goes down to 40° F while the gauges read: High-side 175psi, Low-side 33psi. The Expansion Valve is noisier than before so I will vent a small amount of R134A and see if the noise improves/disappears. If not I will vent a little more out and repeat until the noise stops.

 

Thanks for everyone's help (Turtlehead). I have learned a lot, but have come to accept that I simply have a weak Chinese clone of what I should have: a fine Japanese Sanden compressor.

[Turtlehead]

Sounds like your system is working a peak performance to me. You can cross reference your compressor number with a 95 accord LX wagon 5 spd if you like. If they are the same I have a used Honda compressor I can send you. The clutch is fine but I would rebuild it before installing...