My A/C system is falling apart.

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Before I get anything fixed, everything is going to be broken and Im going to end up replacing everything!
It started with the compressor making rattling noises occasionally. It hasnt made it for some time but it never was consistent. I checked and adjusted the clutch with no change. Still dont know if it wants replaced or not.
Then it was not working worth [censored] last year, so I bought a set of gauges and filled her up. It was nearly flat.
Couple months later it wasnt working again, so I filled it up again and bought a UV flashlight to look for the leak. Found a crack in the condenser so I started acquiring the tools to replace it.
Today I was putting it on ramps. As I was giving it some gas to get up them, smoke started rolling out of the hood. Key off, popped the hood. The smoke was coming off the passenger manifold and the starter was wet. I thought it looked like coolant. I couldnt figure it out, and I was halfway up the ramps so I didnt feel comfortable getting under it.
I started it back up and got it on the ramps proper with no further trouble.
I still couldnt figure out what was going on once I got under it. I thought it was a bad external headgasket leak. I started it up again and revved it from under the hood, what do you know, but the high pressure relief on the back of the compressor [censored] and there was the smoke.
I shut the A/C off and grabbed the gauges. After they were hooked up, I monitored the pressures. They were 35/185@75F ambient with MAX A/C, full fan and all the doors open. I gave it some gas, the high side started flying up toward 400 before the compressor unlatched. Which makes me think it was opening for a reason, but then after that it relieved once at about 225psi and another time at around 300 so I dont know if its a bad valve since the Ford spec is it to open between 550-600psi.
 
The relief valve isn't the problem. You shouldn't be anywhere near 400 psi at those temps.

Did you replace the condenser? How long did you evacuate the system? You may have air in the system, high high side pressures with normal low side pressures can be a clue.

Is the fan working properly? Is the condenser clean? You might have a restriction in the system as well.
 
That was my suspicion that something is off. I had never seen the high needle start flying like that before.
I have not gotten to replacing the condenser yet. Fan works great; its the good one from before they neutered it trying to save money. Condenser is reasonably clean. Could it be an over charge too?
 
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Is your compressor mounted low? I looked up yours and it looks a lot like the Denso in my 02 Tahoe. I will relate my story and maybe it will help.

GM trucks (GMT800 series) used a low mounted Denso compressor and due to some design issue, liquid freon would reach the compressor and 'slug' it. My truck has a dedicated belt for the A/C and it would rattle like crazy, braking 2 belt tensioners, when I accelerated. The compressor was being hammered and bits were coming loose into the lines and plugged up the rear air TX valve. The front air still worked as the orifice has a screen on it. When something restricts the lines the high side pressure can spike. I vacuumed the system and played with the pressures to stop the rattle but the damage was done.

I am thinking something similar happened to you or maybe the compressor is just worn. I am thinking there may be grit in the system and you got a pressure spike or the compressor over heated and the relief vented a bit. Like the relief valve on a hot water heater that never seems to seal right again, some gunk is interfering with the compressor vent so it pops at lower pressures.

My cure was to clean the TX valve, blow out the lines (the front was protected by the orifice screen but I did them anyway to get the oil out) and the condenser. I put a screen kit on the suction port of the compressor block, replaced the orifice (just in case), dryer and the compressor. I measured the oil in the old compressor and what blew out of the lines and added that amount of PAG oil from the compressor kit. After vacuuming the system for 30 minutes I closed the valves to watch for leaks or moisture boil-off. After 20 minutes the gauge went up a few hairs so I vac'd another 30 minutes and the needle held after that. I looked up the freon capacity and recharged the system by weight using small store cans and a digital mail/kitchen scale. Since I already did the oil I used pure freon.

I got the compressor kit off eBay for around $250. It came with compressor, dryer, o-rings for the lines and 2 bottles of oil. My only issue was that new compressor did not have a high pressure switch on it and I broke mine getting it off the old one. A trip to NAPA took care of that. My ending pressures were, IIRC, around 40/320 on a hot day in the upper 80's.

It was my first time working extensively on the closed system of an A/C but it all worked out and I am a happy camper.

Best of luck with yours.

Ed
 
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air/moisture can cause problems. But it seems like there may be a restriction on the high side.

As compressors wear they do shed wear particles like teflon, or if they really crater - metal bits/chunks.

Since you suspect the compressor to be on the way out (though it built up pressure pretty darn good, lol) I agree with grebbler, replace the TXV or orifice tube, it is probably partially plugged. With low compressor output of refrigerant is does ok, but rev the engine and it either cant pass enough through the screen on the orifice tube, or the TXV is not opening and/or blocked.

Also since it is leaking from the high side you probably lost some oil (oil carries best on the high side) so that could also cause extra compressor wear if enough oil was lost.

Do you know if it uses a variable or fixed displacement compressor?

If you open the system it is always a good idea (and recommended) to replace the receiver/drier or accumulator

If it were me I would probably put on a new compressor as well as the condenser. It would stink to have the compressor crater shortly after and clog up your condenser (assuming it is parallel flow and not the old school tube and fin)
 
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I use BrakeKleen for a flush....copious amounts. I plug the outlet and "fill" it and blow it out with compressed air...over and over and over again. The nice part about using BK is it evaporates. Typically once I'm done cleaning it, I'll blow ac oil through the coils as well since the refrigerant will pick up excess anyway (I reduce the amount required in the system by about 1/4 oz).

Right or wrong and probably contrary to many peoples opinion, it works for me and has worked for many years. The specialized ac flush works well too I suppose.
 
Originally Posted By: Fleetmon
I use BrakeKleen for a flush....copious amounts. I plug the outlet and "fill" it and blow it out with compressed air...over and over and over again. The nice part about using BK is it evaporates. Typically once I'm done cleaning it, I'll blow ac oil through the coils as well since the refrigerant will pick up excess anyway (I reduce the amount required in the system by about 1/4 oz).

Right or wrong and probably contrary to many peoples opinion, it works for me and has worked for many years. The specialized ac flush works well too I suppose.


You are right about the specialized AC flushes being way overpriced.
 
So, I had it evac'd. They pulled 3.25lbs out. Spec is 2.375lbs. So a little under a pound overcharged. Anyone think thats enough to cause this? Im kinda tempted to (once I get my scale) recharge it along with a couple ounces of oil and see what it does, but then I would have to have it evac'd again before I can put in the condenser.
 
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