Good afternoon, I'm reaching out from the deep South about a problem I'm having with my AC system. I own a 99 Mustang V6 and the car's RPM increased every time I turned on the AC. At that time, there was enough refrigerant in the system so it wasn't a lack of refrigerant. I finally figured out that the AC low pressure valve also know as the AC clutch cycling switch is faulty. After 21 years, I wouldn't doubt it either. It turns out that I tried to change this part myself since it looked easy enough but the refrigerant came out. I guess the valve on the accumulator didn't closed and kept coming out. I tried my best to change the part and replace the o-ring as quickly as possible but enough gas had escaped and now the AC clutch on the compressor is not engaging. I know the system is low on refrigerant and the easy thing to do is just to fill it with AC Pro or any other brand out in the marketplace. My question is since the system was open for the time I was trying to replace the AC low pressure switch and the O-ring, does anyone know if I now need to replace the accumulator? Again, the system still has some refrigerant but it's low to the point that the AC won't work and I know the system does that to protect the compressor. Also is it a good idea to evacuate all of the remaining refrigerant and to put a vacuum on the system to take out all of the moisture?
Your description of what took place leaves me with enough questions to recommend you take it to a shop where they can do a vacuum drawdown and fill the system with a set full set of gauges. They can make a determination on any other parts needed (I suspect not if you were quick about the changeout).
I have to admit I wasn’t quick about it since I wasn’t expecting gas to leak out. The gas is under enough pressure that what I might perceived as a small amount might be a lot.
So yes, there is not enough refrigerant in the system to make the AC clutch engage. Now, I didn’t change any major piece in the system like say the compressor or the evaporator. I just let some of the refrigerant escape by accident. Would this be enough reason to replace the accumulator? The repair manual says every time the system is open to the outside like in the case if replacing a major element in the system.
As you are aware, you usually get a pffffsssst of freon when removing the low pressure switch...the valve is supposed to stop the flow. If you had a steady expulsion of freon for...one, two, three...thirty...sixty seconds (I can only guess), then there may have been some moisture introduced into your system. The accumulator's purpose (as you know) is to eliminate debris and moisture in the system...too much moisture can result in freezing of the expansion valve rendering the system inop, and in extreme cases, damage to the compressor. That about exhausts my limited knowledge of it. The question you are pondering is--did the length of time you experienced freon loss introduce enough moisture into the system? Unknown. I suspect that when you realized it was coming out, you hustled to get the new piece on...so the time lapse (while painful in slo-mo) may not have been that great. Under these circumstances, if I needed to save money, would I try to charge it myself first? Probably. Roll the dice...tip your waiter.
((Btw, and I hope this doesn't jinx me...I have not had any of my vehicles on a regulation AC manifold set, vacuum pump, etc and only added freon once a year for probably the last twenty.))
Yes, I think that's the question I need an answer to. I figure it's either I refill the system with something DIY like ACPro or let a professional evacuate the remaining refrigerant and put a vacuum in it to pull all moisture. Well, thanks a bunch Storms Edge for your input. I really appreciate it.
So I found out that the AC system was completely empty and the schrader valve in the accumulator was the culprit. I can't believe one little thing like that could've given me so much work. Anyway, I went an replace the schrader valve and the system was again ready to be vacuumed to see if it could hold pressure. So I went to my local OReilly's and rented a vacuum pump and an AC manifold gauge. Put the manifold gauge together and place a vacuum on it. Left it there for over 1 hour and a half. I went a head and closed the high and low ports to see if it could hold the vacuum and it held it. So after that it was just two bottles of EZ Freeze and got a cold air once again.
I have to point out that I got great guidance from two videos on youtube.
One is this how to add refrigerant to your AC: View: https://www.youtube.com/watch?v=zAageqHBj4k