Automotive Air Conditioning Information Forum (Archives)

LCD on Wed February 02, 2011 12:48 PM

Year: 2002
Make: Honda
Model: Accord
Engine Size: 2.3
Refrigerant Type: R134
Ambient Temp: 60
Pressure Low: 10
Country of Origin: United States

Hi

I'm having an issue with the a/c in my Honda Accord. It has never given me trouble untill a few weeks ago. Stopped cooling all together. Clutch engages when a/c is turned on. Sometimes a/c will not turn on and fan don't either. The manifold I attached to the low side showed about 10 psi. Wouldn't the low pressure switch keep the compressor from turning on if there was low freon?

Kinda stumped, thanks for any information.

Dave

Cussboy on Fri February 11, 2011 7:18 PM

I'd check your refrigerant pressures at 2000 rpm, low and high, with good gauge set. if you live in Hawaii or Florida. Otherwise, I'd wait until May.

LCD on Mon February 14, 2011 2:07 PM

Ok as requested, I rechecked the Honda gage pressures at 2000 rpm. First I'm using a set of Mac Tool A/C manifold gages. I checked the gages on my Toyota truck, (of which I purchased and installed an a/c system from Arizona Air). Still running strong! Toyota specs @ 69 F 30 low/ 200 high. So the gages are not in question.


Ok the Honda... A/C off 45 low/ 50 high outside temp 69 F.

Cut A/C on: Fans ON
Clutch engaged
10 low / 50 high (you know when you turn on the A/C system, the idle changes putting a load on the engine. (((There is no change in idle at all)))
vent temp 70 F no change at idle or 2000 rpm's
-15 low / 50 high
Thanks for any help
Dave
(I had to create another name LCD, this is actually Lowcountrydave, why is this site sign in so screwy?!

TRB on Mon February 14, 2011 4:20 PM

Pressures seem very low. I would like to know how much refrigerant is currently in the system. Which means reclaim and measure.

If one posts before logging on you will not see your reply. Other than that forum has worked very well since 2001. Not going to upgrade for 1 minor hiccup.

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NickD on Mon February 14, 2011 4:47 PM

Hondas' kind of left my life with devaluation of the US buck. But was very typical for Honda to maintain both the sight glass to see bubbles at 2,000 rpm with ambient temperatures of 80+*F with a clear glass if fully charged. Also used a dual function switch and as long as the high side pressures were greater than 40 psi, the compressor would switch on.

EPA states the average R-134a vehicle can lose 10% per year and if this car was never topped off before, may never find the source of the leak. EPA is politely asking the OE's to do a little better, but will nail you to the cross if you release any of it. Over a nine year period based on this average, you would only have about 38% left.

Its not easy to top off a system without adding air into it, one good reason to have a recovery machine, find out what's left, add to that, and put it back in. But also reason for concern, if you lost refrigerant, can lose some oil as well. That has to be looked over very carefully. And just use pure R-134a, tons of crap on the market.

mk378 on Mon February 14, 2011 7:04 PM

Looks like a near total leak-out. The cutout switch is on the high side, so once the pressure there is high enough to engage it the first time (about 50 psi), it will stay engaged even with very little refrigerant.

When the static pressure (A/C has been off for a long time) is less than the saturation point you know there is no liquid refrigerant in the system and it is so undercharged it can't work. The saturation pressure corresponds to the ambient temperature read on the R-134a temperature scale on the inner part of the gauge dial. This is the only reason you should ever use that scale.

Also it sounds like you were opening the manfold valves while measuring. Always measure pressures with the valves on the manifold closed. They are opened only to charge or evacuate through the yellow hose. Never open the high side manifold valve with the compressor running.

Edited: Mon February 14, 2011 at 7:07 PM by mk378

LCD on Mon February 14, 2011 10:43 PM

A couple years ago I did top off the system. I was getting around 38 at the vent. I cracked the yellow supply line on a new can to purge most of the air out. Hoping to not add any air to the system. I'm going to check for leaks and other potential damage to the system. I'm trying to not have to take it to the shop. But if I have to I will.

Dave

NickD on Tue February 15, 2011 6:16 AM

Unfortunately, all MVAC systems leak, fairly difficult to find a leak that is one ounce per year, even two ounces per year. Over a five year period with a 24 ounce system, that adds up to 5-10 ounces of refrigerant lost or 20-40% of the system capacity. A bad joke are these R-134A quick coupler ports, the disks are rather large and have to seat properly. Only thing guy can do is make sure the neoprene seals are good. Then they make these damned things out of plastic where they use to be metal. Second source is the compressor seal itself, third source is the use of O-rings that can dry out, particularly in the high side where the temperature is great. Evaporators and condensers are manufactured with an alloy grade of aluminum that isn't even as good as a throwaway aluminum pop can, so you wonder why you have problems?

Mythbusters had a segment on if can you polish a substance with an FCC approved word of poop. Should also have a segment can you make an MVAC system that is leakproof made with the same substance! But yet our glorious EPA turns a blind eye to this, but picks on the tech to recover refrigerant. What refrigerant? If it all didn't leak out, wouldn't be a problem!