rockola1971
Full Access Member
Charge by weighing it in with a scale or using the pressure chart for r134a. You will need just over 3 1/2 (12oz.) cans.
A/C broke...re-visited!
- Thread starter Steve Waddington
- Start date
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swathdiver
Full Access Member
Cans are 12 ounces, so put in 3 and then weigh the last can with a scale.
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Steve Waddington
Full Access Member
So I'm assuming that's 12 oz of product inside the can? Then the can weighs something too. So I should use 3 cans, weigh an empty one, subtract that weight from the last can, and add that amount?
swathdiver
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rockola1971
Full Access Member
No. Then youll end up with 48oz total in the system. Dump 3 whole cans of R134a 12oz (no leak seal) in a completely evacuated system and vaccumed down. Then weigh the 4th can total weight(with charge hose connected to manifold) Subtract 7.2oz mathematically from the 4th cans total weight(which will include the charge hose attached) and that will be your target weight to get to while charging the system with a scale underneath the can.
FOr example the weight of a full can with hose attached is 19oz. You will subtract 7.2oz from 19oz which equals 11.8oz. That(11.8oz) will be the target weight at which you will stop charging and there will then be a total of 43.2oz in the system. 12+12+12+7.2 =43.2oz.
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Steve Waddington
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OK...got all my parts and tools coming in. I have an appointment for Tuesday at a shop that will remove all the R-134 from my system so I can start! What a pain. Most shops around here don't want to do it if you're not letting them do all the work!
rockola1971
Full Access Member
Pretty typical. Because they know how much they can get out of people over a/c repair and parts markups. Especially in areas with high humidity and temps. It aint hard to keep busy working on A/C in the south...try selling them a heater though. Most people have zero inclination to understand how an a/c system works nor want to work on it. The magic of it is once you know how an a/c system works and what parts of the system are involved, you just learned how to work on a home a/c system(central air and window unit), heat pumps, refrigerator/freezer, standalone freezer, walk in cooler/freezer, dehumidifier and even industrial A/C and Chiller. They are all a/c systems. The only true differences are the way the refrigerant is metered in each type of system. They all have compressors, evaporators, condensers, some sort of refrigerant metering device and refrigerant of some type.
FYI-- A heat pump is an a/c unit with the refrigerant direction running backwards. (theres a reversing valve that causes the refrigerant to go the opposite direction of its path in an a/c operation). Other than that reversing valve a heat pump is a plain old centrail air/air conditioner.
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It is a costly proposition in time and dollars to get setup to properly do AC service. Anything past a simple recharge for the typical shade tree mechanic might be best handled by AC specialty shop. I have several thousand dollars worth of tools that can only be utilized for AC servcie, that would be a terrible waste for a oneoff type repair...... If you are like me and have older vehicles and rental properties it is worth the effort though. Even after all these yaers I am still fascinated by how refrigerants works, latent heat thermodynamic physics still fascinates me. It is like MAGIC! LOL
rockola1971
Full Access Member
The gauge set and vac pump are fairly cheap enough. Its the recovery unit that costs but a DIY can just drop buy a shop and pay them to do an evacuation. Everything else as long as done correctly is easy enough and cheap enough....without having to pay for parts markup at a shop which would pay for the gauge set, vac pump, valve core tool, PAG oil and refrigerant.
