A/C repair

[howzzzit]

You didn't say if it holds 18 inches when you close off your manifold. Tell us and I can give you some ideas. I sold pressure switches for many years and have never seen one with an o ring. They are a brass flare fitting with a core depressor. Metal to metal flare seal. Did you borrow a vacuum pump?

[kaycee]

Yeah got a pump ,after calling it quits last night I left gauges hooked up and it was still at 18 " this a.m. I only ran pump for about 15 min should I run longer.

[howzzzit]

Your pump should almost peg your low side gauge in the vacuum range. It should look like almost 29 inches which you'll never achieve. 28 after shutoff and holding about as good as you'll get. The fact it held overnight looks good. Let me ask about your pump. Does it have fresh vacuum pump oil in it? I have "fixed" several pumps that wouldn't pull a deep vacuum by simply changing oil. Technically you are suppose to change the oil after every use. In the real world techs don't do it and use the same oil until it smells like fish. I've left pumps on all day, but they usually pull down after a few minutes. They are not removing moisture after on 15 minutes and moisture is the number one enemy of a system. When you're in a deep vacuum the pump is removing any moisture in the system so let it run. Is your low side gauge accurate? Maybe you're lower than it reads. Also, are you pulling the vacuum through both sides of the manifold? If so, just try pulling through the low side only. That will eliminate 50 percent of possible manifold and hose leaks. Using just the low side is good enough on a small system.
Post your results

[kaycee]

Borrowed pump and gauhes they are Harbor Freight specials ,oil looks good smells like oil. 30 min pull on lo side makes no change

[howzzzit]

But it holds the vacuum?

[kaycee]

Yep I think this gauge is off , Holding vacum for last hr or so AGAIN

[howzzzit]

Watch it overnight. Shouldn't move. Looks like you may have a fubar low side gauge or a vacuum pump.

[kaycee]

Held vacum all night ,I try and find another gauge set today and pick up a can of 134 . So I used a accumalator for 87 C-10 1 port for the low switch and is the other 1 for lo side test port ,I have the hose kit from V.A. and I been using the ports that are attached to the compressor end wouldn't think it would make any difference but never hurts to ask

[howzzzit]

Doesn't matter if they are all access ports with cores. If you're gonna charge it I always purge the charge lines with refrigerant with a small trickle while attaching the line to the system. You don't want any air in the system. You'll find it easier to charge on the suction side (low side). Charge vapor only on the low side (can upright). Upside down would be charging liquid and that's not good for the compressor. Got it?

[kaycee]

Sure appreciate the HELP you guys are giving me ,got another set of gauges on it now pulling vacum and it is reading 25 ish my good eye is not so good anymore lol will see what happens the next day or 3 maybe try and get a charge in it ,So I put recommended oil in compress. can I put a squirt of dye in it to help in detecting future leaks ? Allso the low press. switch I just run my green wire to it then switch to compress. People talking about 2 wires all I got is a hot(green) and ground.

[howzzzit]

Dye is up to you. I wouldn't. Just refrigerant and oil. Since your system is new the most likely leak would be a fitting. If one of the coils leaks you'll know. Where there's a leak there's oil residue. If you see that start checking with refrigerant leak detector soap. If the dye were to show it would still be oily.
Be sure not to get air into the system when charging. The oil travels with the refrigerant.

[kaycee]

OK appreciate it hopefully all goes good

[howzzzit]

How did this turn out for you?

[kaycee]

Well I never got it charged up yet, my regular job is allways getting in the way lol. Should have it done this week , i left the gauges on it for a couple days and it finally bleed off . I'm hoping it leaked through the gauge connections ,will update when I get charged

[kaycee]

Got her charged up today ,I have put 2 12 oz. cans of 134 in so far and it has cooled off some .I was charging this i the garage so it might cool down more outside getting fresh air circulating through condensor. Might try and add another half can, what should I be looking at for pressures ?

[howzzzit]

https://www.rechargeac.com/how-to/ac...ressure-chart/

Put a fan in front of the condenser

[kaycee]

Ok was afraid that was the case, I added another 1/2 can of freon and it helped a bunch, it was cooler today high side press. was a little lower than I liked but low side was good . I have a electric puller fan on rad./ engine side then condensor and a trans cooler in front. Would switching out the electric fan back to the original help anything ?

[howzzzit]

Sounds good. Check your pressures on a hot/warmer day. Sounds like you're pushing plenty of air. Run it.

[kaycee]

Wow this works pretty dam good ,cruised around this weekend and she blew cold the whole time. Thanks everyone for the HELP