Charging Compressor with AC Pro

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You have a leak if the refrigerant level isn't remaining the same year after year...
 
Yeah, I got a used compressor to put on. Don't have gauges. Was curious if this stuff was sufficient to put in with builtin gauge.

Originally Posted By: Reddy45
You have a leak if the refrigerant level isn't remaining the same year after year...
 
I haven't used that brand, but I prefer to use a manifold set like the ones from Harbor freight and buy the small cans of R134a.

https://m.harborfreight.com/ac-r134a-manifold-gauge-set-60806.html?utm_referrer=direct%2Fnot%20provided

That manifold set will let you get a more accurate reading of the high and low pressures and the hoses are longer which sometimes you need. I had a 98 sienna and the low side port was back near the firewall and with a small hose you always risked burning yourself even with coveralls on. As you had to lean over the engine.

Last time I bought r134a I was able to get the small cans from Big Lots for around $5 a can.
 
Don't use anything that has a sealer in it. Just straight R134. That stuff says it seals leaks so I would not use it. Using a can like that is also not the correct way to recharge an AC system. It needs to be vacuumed down to boil the moisture out and to see if you have a leak somewhere. You then charge into the vacuum created by the vacuum pump with the correct amount of refrigerant.

Wayne
 
In my area, WalMart has their Supertech branded 12oz r134a on shelves for under $5/can. I'd use that over the more expensive A/C Pro. Use the savings to buy a set of gauges.
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The gauges are helpful for when you pull a vacuum too (can see if the system holds...).
 
Did your old compressor fail? Did you flush the system before putting on the used replacement? What about replacing the filter drier? Are you planning on pulling a vacuum before you charge the system? If you don't do this stuff it won't matter how you charge the system or what product you use.
 
When you opened the system to install the new to you compressor you completely lost the old refrigerant charge and also let air into the system. After you install the new to you compressor the system has to be pumped down with a vacuum pump before it can be charged with new refrigerant. And the amount of refrigerant needed to charge your completely empty system is way more than you get from only one can of AC Pro. It is best to charge a completely empty system using gauges that let you see what the high side and low side pressures are.

In short, you really should take it to someone who works on vehicle AC systems for a living because they will have a vacuum pump to vacuum out all the air (and any moisture that is in that air) and they will know how to charge a system.
 
AC Pro is meant to be used to top off a system that has lost some its charge due to a very small leak. It is not anywhere near enough to charge a completely empty system, and you have to pull a vacuum on the system with a vacuum pump to get all the air and moisture out of the system before you can charge it.
 
Originally Posted By: DerbyDave
Did your old compressor fail? Did you flush the system before putting on the used replacement? What about replacing the filter drier? Are you planning on pulling a vacuum before you charge the system? If you don't do this stuff it won't matter how you charge the system or what product you use.


+ 100 !!!!!!
 
Did you pull the vacuum in the AC system yet?
If not, you need to do it first regardless of the gauge used.

For this you need either a vacuum pump or a compressor and a venturi pump.

When the system can hold the vacuum for at least a couple of hours after pulling the vacuum, then you can charge it.
 
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If the vehicle has a variable displacement compressor the gauges really only serve as a reference and an apparatus for pulling the vacuum and adding the refrigerant.

Its more important to add refrigerant from empty by the weight listed as its total capacity. The system will adjust displacement of the compressor in order obtain about 35-39 PSI on the low side, therefore adding refrigerant based on pressure shown on the gauges is almost meaningless once the system reaches a point where it can maintain the set pressure on the low side.

with a set displacement compressor you'll have to look up what the best practices are for that application. For example, charging to specific high and/or low side pressures with the AC on high, on an 85 degree day, with the radiator fan on high, engine RPM at X,XXX, etc.
 
Professionals don't use stop leak stuff.
Professionals charge an arm and a leg to find a leak, fix it using $.25 O-ring seals, and then recharge with straight up, cheap formula R134a.
 
Use that AC Pro stuff only if the car is on its last legs or if fixing the AC the right way is too expensive. I doubt a 1993 S-10 has a variable displacement compressor, it probably uses an old school Harrison R4 compressor or similar.

You need to pull a vacuum to evacuate the system and boil off any residual moisture - AZ rents out pumps last time I checked and it should be charged by weight ideally. The best DIYers can do is charge according to pressure and get close enough.

Flushing the system, replacing the orifice tube and accumulator aren't a bad idea, the former is highly recommended. Did the compressor fail? Parts for older GM systems aren't terribly expensive.
 
Originally Posted By: wtd
Don't use anything that has a sealer in it. Just straight R134. That stuff says it seals leaks so I would not use it. Using a can like that is also not the correct way to recharge an AC system. It needs to be vacuumed down to boil the moisture out and to see if you have a leak somewhere. You then charge into the vacuum created by the vacuum pump with the correct amount of refrigerant.

Wayne


100% correct . Vacuum it down . Check for vacuum leaks . It may still have a leak when it is under pressure , but this is the first step .

Wyr
God bless
 
The question about why the compressor is being replaced hasn't been answered. Did the pump shred itself sending debris into the rest of the system? Even if the system is properly evacuated and correctly charged with refrigerant and oil and no leaks are found it won't matter if the junk isn't flushed out first. If you don't know what you are doing don't just try to wing it and hope it all turns out ok.
 
In addition, I would not use any "USED" compressor.

The labor cost on flushing and vacuuming and recharging are already expensive.
If the compressor goes bad again shortly, even with warranty, you still have to shell out more than the price of the compressor.

I am assuming this is a GM pick up with a troublesome compressor to begin with.

JMHO.
 
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