I have a 1993 Accord and the A/C has started to not cool as well as it used to. The clutch kicks in and the compressor turns on and it does cool but only about half of what it used to about 2 months ago. I looked under the hood and (my engine is very clean) noticed that the compressor has a coat of oil on it so I figured it is leaking and some seal has blown. To bring it to a shop is going to cost a boat load so this is what I was thinking of doing. Tell me what you think.

1. Remove and replace the compressor with a remanufactured unit.
2. Replace the receiver dryer.
3. Bring it to an A/C shop and then have them evacuate the system with the new parts on it and then charge it up.

I am not sure if they will have R12 but I guess they can put R134 in it. Does this sound like a sensible way of doing this job??

 

This is a good plan.

Replace compressor w/ a good used compressor or quality rebuilt (check ackits.com). Be warned a lot of rebuilts are poor quality, so be careful.

Replace all orings in connections; condensor, evaporator, receiver/drier, compressor. You should also consider removing and cleaning the evaporator, and replacing orings on expansion valve and temp feedback tube. They age and begin to leak on these cars and yours are likely leaking. You may want to blow out (air or air+flush) the condensor and drain the evaporator of mineral oil (R12 lubricant). Evaporator is difficult to drain so just get what you can out.

If you've never replaced the blower motor, it may be near end of life and this would be easier to replace w/ evaporator removed. It can wait and be done separately, when/if it fails.

You could install the new lubricant in the system before closing or allow the shop to do this.

Shop should not charge more than $100 to do this job, IMO. First thing they will do is install R134a adapter fittings on the R12 connect points. Next install lubricant (make sure they understand this if you don't install), close and leak check w/ vacuum pulldown, vacuum for 1/4-1/2 hr, and charge into system.

You could almost pay for cost of tools you'll need to charge yourself w/ what you'll pay the shop; check ebay for a used vacuum pump and manifold gauge set. I think you can find these for about $150 total. Then you're set for life.

good luck

 

Texas, I am glad you latched on to this thread because I have used your advice in the past and it has always been spot on!

Here is what I did. I took the car down to our local Honda specialist and had him take a look at it. He said the oil I saw was probably from another source and not from the AC because he said it was only about 1/2 a pound low. I brought it to him because he has all the gauges and actually knows what he is looking at.

From what he said, he said the expansion valve appears to be stuck open. He put in about 1/2 lb of Freon and said to just run the car around for the weekend and see if the valve frees itself with the flush he did. I think he evacuated the system and recharged it. He said in the past he has seen where people drive around and the valves free up. If not he said that a new Expansion valve should be put in along with a new receiver drier. He said that it is a pretty long process to do this 3-4 hours. He said I could have him evacuate the system and then I could install the parts and he would recharge it for me.

What is involved in changing the expansion valve and receiver dryer??

 

to replace exp valve you need to remove the glove box, remove the evaporator unit, take it apart and replace the valve,,,,,a/c system needs to be evacuated then put under a vacc and then recharged ..

rec drier is real easy to replace , just disconnect the lines and remove the bolts that attach it ,,
this would be a good time to retrofit to r134-a ,, also make sure to get some new o-rings

if you know the a/c pressure readings ( high and low ) post them here..

 

I will get the readings and them post them.

So the exp valve is behind the glove box and evaporator unit??

 

Its inside of the evaporator box. You have to disconnect the two a/c lines going into the firewall from the engine bay side. Unplug a sensor from the evaporator box. Unbolt the evaporator box and pull it out.

Like Desert said, replace all o-rings throughout the system. You can use a product called Nylog, a slimy goo that helps prevent the o-rings from dry rotting.

 

Are there other o-rings in other parts that need to be replaced in areas other than the expansion valve???

BTW the pressures are 250 on the high side and he said the 250 was fluttering on his gauge a little. The low side was between 45-50 and was solid. He said the low side should be between 20-40 and fluttering a lot as the valve opens and closes. He believes that the valve is stuck open. From what he said, I need to replace the expansion valve and the receiver drier. How is all of this sounding??

 

I'm skeptical about expansion valve, but you need to remove the evaporator to replace orings, so replace expansion valve at same time. You can buy a new expansion valve set for R134a which will improve performance somewhat compared to the R12 expansion valve. Try ackits.com for replacement expansion valve.

Removing evaporator is not difficult. Be sure to use two wrenches to release the primary connections on the engine side of the firewall. One to hold the evaporator side of the tubing and the other to turn the nut. Connections can be quite tight.

Once disconnected, the evaporator box is removed as a unit. Get a manual download from the Online Manuals diy section to insure you know where all fasteners are located. I found that a long flex-extension and ratchet driver were very helpful to access the nuts and bolts retaining the evap box. A deep 10mm 1/4" drive socket is also helpful.

Take your time opening the box and avoid damaging the foam supporting the evaporator. You may notice some evidence of leakage around expansion valve connections and thermal feedback connections. All orings should be replaced. Clean and polish the mating parts carefully (don't scratch) w/ very light brushing w/ soft abrasive scrub pad or other light abrasive. Fine emery cloth is very good.

good luck

 

I am obviously not a professional and am curious to know your take on this. He said that the low pressure should go lower than it is and that the pressure should go up and down as it opens and closes and he did not see that happening. Do you know of any other reasons the low pressure would be too high or that it wasn't going up and down?

He said that he will be replacing the freon with a synthetic type of R12 so should I stay with the stock replacement or look for the R134 model??

Also, do you see a problem with going with an aftermarket expansion valve? There is such a large discrepancy in prices between the Honda OEM valve and the aftermarket one I can get at Advance Auto.

 

If the compressor is cycling, the low side pressure should stabilize until the compressor cycles off, and pressure will rise steadily to perhaps 45-55 psi and compressor re-engages. The expansion valve does not react rapidly at any time, in my experience. When compressor re-engages, the pressure will rapidly decline to low value, about 30 psi for R12. This would be for a fully cooled cabin.

If compressor stayed on continuously, and low side stayed around 45-50, the heat load would have to be very high in the car, or possibly a defective expansion valve, or overcharged.

For instance if you opened doors and windows, AC on max fan, and recirculate, the compressor should run continuously in summer temps. If outside air was 90F, the air from vents might be 55F and low side pressure would be 45-55 psi.

If you close windows and doors, max fan, recirculate, the vent air should gradually cool to about 40-45F (in a good system), and low side pressure would be 30-35 psi.

I've never tried any of the R12 replacement refrigerants. These are mixtures of several refrigerants, but mostly R134a. They are not favored on the automotive AC forum, ackits.com. Either stick w/ R12 or switch to R134a is their usual advice. You should puruse the site and form your own opinion.

good luck