1990 honda retrofitted to R134 , holding pressure, holding vacuum , not cooling

[greenquark]

Hi there,

My AC didn't operate for a few years. I finally decided to fix it BUT as cheaper as possible . Since I store it during winter and the manual says I should operate de AC at least once a month, even in the winter.

I replaced o-rings, Clean condenser,expansion valve and evaporator. I replaced the dryer too.

I took it to a questionable shop( I realize reading stuff in forum like this)

Put the vacuum pump up for an hour . It held vacuum. The guy proceeded to fill it up. He try to refill by pressure not by weigh. The high pressure gauge didn't go up at any point. The low pressure was at 65 then went to vacuum. He concluded the compressor was bad.

The compressor engages and make no noise. I have read that is really weird for a compressor to go quiet or little by little. So I have my doubts.

I cannot have the readings on the high pressure port. But So far I have this:

- high pressure line out of compressor HOT.
-Line in to the dyer cold ( I can also see liquid state on the sightglass on the dyer)
-Condenser cold.
- High pressure line into the engine wall ( to the evaporator) colder than ambient
-Low pressure line out the evaporator warmer than ambient (or equal) ...not cold.
-Hissing sound coming out of the evaporator ( I have been told is the freon going through the expansion valve)


IS there any way I could differentiate between expansion valve gone or compressor gone?

[mk378]

It sounds like there is a blockage in the condenser. No parts of the high side should be colder than ambient.

If there is liquid meeting a restriction, the parts after the restriction will get cold because the pressure drop works like an expansion valve.

[greenquark]

It sounds like there is a blockage in the condenser. No parts of the high side should be colder than ambient.

If there is liquid meeting a restriction, the parts after the restriction will get cold because the pressure drop works like an expansion valve.

Thanks for the answer! Actually it is something new no one has mentioned to me before. And it makes sense. I will be sure to confirm the actual temperature and compare it to the ambient. By touch, the high pressure line going into the evaporator is colder than the low pressure line getting out of the evaporator (100% sure) . And by touch it is colder than any aluminum stuff around it.

does a blokage in the condenser explain the low pressure going down almost to zero when the ac is turned on?

I guess I will have to put everything apart , flush it and putting back. Any advice?

[Cusser]

does a blockage in the condenser explain the low pressure going down almost to zero when the ac is turned on?

Yes a blockage there will cause higher high side pressures, and lower low side pressures as little refrigerant is getting through to the low side.

I have used aerosol flush, sprayed through backwards to the normal refrigerant flow, then blew dry with compressed air.

[greenquark]

does a blockage in the condenser explain the low pressure going down almost to zero when the ac is turned on?

Yes a blockage there will cause higher high side pressures, and lower low side pressures as little refrigerant is getting through to the low side.

I have used aerosol flush, sprayed through backwards to the normal refrigerant flow, then blew dry with compressed air.

But my high pressure is not getting high...it stays constant

[mk378]

If it's like my '91, the high side port is right before the lines go through the firewall to the evaporator box, so you are measuring the pressure downstream of the condenser. It's only on cars that have the high side port before the condenser that you could see the pressure rise from a blocked condenser.

[greenquark]

If it's like my '91, the high side port is right before the lines go through the firewall to the evaporator box, so you are measuring the pressure downstream of the condenser. It's only on cars that have the high side port before the condenser that you could see the pressure rise from a blocked condenser.

Yes, the high pressure port is right before the line goes into the car.

I will dismantle everything ...give it a cleanup and put evertyhing back

I Will replace the Expansion valve. I just replaced the dryer...If I open the system and take the dryer out and "seal it", can I use the same one or should I get a new one?

[greenquark]

The line getting into the condenser is hot (not warm but hot). The same line leaving the condenser is somehow cool.. Not cool but definitely colder than ambient.

Is this the way it supposed to be?

Postby GM Tech » Fri Jul 15, 2016 7:58 am
Depends on the vehicle- all GM trucks (front only systems) have their expansion device (OT) in condenser outlet- so yes, condenser line to evaporator will be cool---Most cars have their expansion devices at entrance to evaporator, so no, it should be warm---A condenser restriction can act as an expansion device as well-- causing a cool pipe...

it is a honda. expansion valve is in the evaporator. After the freon leaving the condenser , it goes to the dryer then the evaporator. If there is a restriction in the condenser. Could I still see liquid state freon on the sight-glass on top of the dryer ? I see liquid on the sight-glass. not even bubbles.

[mk378]

Are you really seeing liquid in the sight glass, or just clear gas? You should see it fill up and clear with bubbles and liquid when you start and stop the compressor.

Do you know of any history of a stop-leak compound being used in this system, or having a blown compressor and replacing it without replacing the condenser?

[greenquark]

Are you really seeing liquid in the sight glass, or just clear gas? You should see it fill up and clear with bubbles and liquid when you start and stop the compressor.

Do you know of any history of a stop-leak compound being used in this system, or having a blown compressor and replacing it without replacing the condenser?

History: I have had this car since 2001. The AC worked with R12. It was retrofitted around 2005 . It worked until I moved to Canada . First winter I stored this car. When I took it out, I heard a hissing on one the line coming out of the compressor and it was a leak . Since I know this AC system must be on at least once per month during winter to lubricate everything, I said : I fixed it and even if it lasts the summer for 100 bucks...it is all good... took apart the evaporator , and TVX, cleaned everything, replaced dryer. Vacuumed the system, it held vacuum. A guy refilled it. God, was I wrong. I have spent 100 bucks already

here is the video of the sight glass with the whole cycle: Ac off, i turn it on, 5 seconds, off again. It looks like liquid to me, but I might be wrong. That is why I was wondering that if the condenser ( before the dryer) is clogged and the freon is expanding before reaching the dryer. I have to see gas at the dryer ...But I am not expert

Thanks a lot
VIDEO
http://tinypic.com/player.php?v=2rp777k ... 4lYppMrKMB