Here's the back story.

2000 Civic EX. (SORRY, I am posting this for my cousin who doesnt have an account, its a Civic.)

A/C worked great. All of a sudden the pulley would make a winding sound at idle.

Well, one day it idled to long and started smoking and smelt burnt. Knew it was on its last leg so whatever.

Well, I bought a new one from Advance along with a drier and replace them recently.

Bought all the necessary tools to draw vacuum and recharge the system.

My compressor came with 1.5oz of "PAG" fluid already. Figuring there was still oil floating in the system, I put 2oz more of PAG 46 figuring it would equate to ~4oz in the system which is what is called for.

Put 1oz in the low side of the compressor and another 1oz on the high side and then bolted the lines back on.

Drew vacuum down for a good 30 mins or so and it held just fine at ~25in hg.

Cool, so now its time to recharge. Hook up the can, start the car, full a/c on, purge the line, open the low side and start to charge the system.

A/C Compressor kicks on and starts up. Blows semi cool.

Here's the problem, the system took one can and was slightly below spec. So I hooked up another can and started to continue to fill. Before really opening the 2nd can it was already very close to spec. 35ish on the low side and 245ish on the high side.. Still blowing warm though.

Knowing the system takes ~22-24oz, 1 (12oz) can cant be right after emptying the system.

Continued to put in the 2nd can figuring it was the cheap manifold gauge set from harbor freight......

Wrong. High side went to 350ish and compressor kicked on and off continuously for 20 seconds or so. I immediately shut the a/c off and started to purge the system back into spec.

A/C didnt blow cold at all, it was sorta cool at best. Night times it would blow pretty cold.

Checked the gauges again and the low side is all the way high and the high side is in the low 120's?

Also, I noticed when driving and the a/c on, I can here a sorta sucking from the evaporator under the dash that is constant and never stops as long as the a/c is on. Upon shutting the a/c off, it will slow down suction until it phases out.


My questions:


When the compressor initially went bad, after replacing the compressor and drier, why would my A/C system be at spec after only 1 can and still blowing warm?

Could I have caused the expansion valve to "go bad" when I over pressurized the system?

At night, my a/c blows ice cold. During the day, 90*+ each day, it blows sub cool.

Thoughts? Suggestions? Opinions?

 

I would find another set of gauges.
A 22-24 oz system with only 12oz in it should not show proper pressures , in fact the low side would go almost into a vacuum. and the high side should be no where near 245psi.

Also you charge the A/C system through the high side, and you should not have the A/C on, the vacuum will draw the refrigerant in.

I am assuming you are using the DIY cans of refrigerant that only has the low side service connector, meaning you had to disconnect the A/C manifold set.

You do know that the system will not hold vacuum when gauge set is removed, the valve is to keep pressure in not out, so I am guessing the system sucked in air, [moisture] when the service connector was disconnected, the whole point of the vacuum is to boil off any/all moisture.

The oil charge should be OK or close enough to work, the correct way would have been to drain the old compressor and put that amount into the new compressor and add an oz to the new filter.

Oil goes in to the suction side of compressor, and the compressor clutch should have been turned, [clockwise] about 10 times and then stood on it's clutch for at least a few min., [longer is better] so oil can soak the front seal.

All the above may or may not explain your problem, and with strange high and low side readings it is a good bet the expansion valve is bad or even the compressor, introducing a liquid into the vapor side is never good, it can work when bumping the system, [adding refrigerant to a low system].

Here is a good description of what happens... http://www.danfoss.com/NR/rdonlyres/.../FSN008web.pdf

I would start again, doing it correctly and see what happens, replace the expansion valve first.

With the system open, you can flush the system as you should anytime a compressor goes west. 94

 

I was always taught NEVER to charge through the high side and only use that for monitoring?

I left the manifold gauge set on and charged through the same middle hose as I pulled vacuum with. AFTER purging the system to relieve any air that may have gotten in the middle line while going from the vacuum pump to the can tap.

The instructions said to turn it 12 times CCW and lube the front seal.




I appreciate the help nonetheless.


I replaced the expansion valve today, vacuumed the system back down, charged through the low side and recharged it to spec. 36ish on the Low side and 240ish on the High Side with decent vacuum at ~-24hG. Everything is mint and my A/C throws snowballs at me.

 

. 94

 

You're right. Perhaps charging through the high side works with sophisticated equipment, for the DIYer you charge through the low side with the ac on. You did it all correctly. I think the second time you started doing it, you just overreacted. The ac compressor will cycle itself on for the first time when recharging once it reaches a minimum amount of refrigerant(pressure) in the system.

Then it will cycle on and off after a few minutes or so each time to keep and maintain a certain temperature at the evaporator.

When you recharge the system it's best to briefly blip the recharge bottle after you attach the hose to get rid of any air, provided you're using the recharge hose coupled onto the can.

 

As mentioned, the OP did have an A/C manifold set and a vacuum pump and he said he connected his refrigerant can to the center hose of the manifold set, other then starting the car, that is the correct way.

Although, if he had tried to charge through the high side with the engine running it would not have worked as soon as the compressor kicked in. 94

 

Depending on ambient temp, 240ish may be a little high. Also did you notice any blackish oil come out of the old compressor or any other part of the AC system that you opened?