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16 votes
Accepted

Is it okay or useful to run heat and AC at the same time?

You're meant to. In fact, in older cars, it was automatic when redirecting air to the window defroster. On this GM control, the far right position would activate the A/C compressor. Almost always, ...
Harper - Reinstate Monica's user avatar
10 votes

Will running engine after replacing A/C components ruin the new compressor before system is recharged with freon/oil?

Your compressor should be clutch driven. If so, then running the engine won't do it any harm. The clutch won't engage the compressor without a refrigerant charge present. With the pressure at ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
10 votes

Is it okay or useful to run heat and AC at the same time?

Yes, it is useful, okay and won't cause any damage. The usefulness comes from the fact that the AC not only removes heat from the air, it also removes moisture from the air (because cold air can't ...
juhist's user avatar
  • 14.5k
5 votes

My AC compressors won't run, and the systems won't take a recharge. What should I check next?

Unless you're completely familiar with vehicle ac systems using all the equipment for diagnosing, troubleshooting and knowledgeable about repairs, your first mistake is using sealer; a no-no as you ...
F Dryer's user avatar
  • 976
5 votes

What exactly is R-1234yf?

R-1234yf is designed to be an environmentally-friendlier, near drop-in replacement for R-134a. Environmental legislations are pushing for refrigerants with lower global warming potential (GWP). R-...
Zaid's user avatar
  • 39.1k
2 votes

Is this a non-puncturing refrigerant can?

The can top picture is a non-puncture can. The tap with a sharp point is the tap for puncture cans. The tap with a flat point is for non-puncture cans. They are very inexpensive.
Jupiter's user avatar
  • 3,222
2 votes

My car A/C lost all of its refrigerant

You clearly have a leak in your AC system as it is a closed system so the refrigerant had to have leaked out. Refrigerant leaks can be hard to find. They have special dyes and sniffers to help ...
MJH's user avatar
  • 878
1 vote

Recharging A/C - adding oil, UV dye, & stop leak

You should never put stop leak in an AC system. It can and probably will damage and contaminate your system. The dyes are recommended, especially on older systems. They may eventually leak so it makes ...
Jupiter's user avatar
  • 3,222
1 vote
Accepted

What happens if you disconnect the AC lines from the compressor?

If you pop the hose or any of the connections, you lose most all (if not all) of the refrigerant. It is under significant pressure. Enough you cannot get things sealed back up before it's gone. In ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
1 vote

Can R-410A refrigerant be substituted for R-134A in cars?

Only in vehicles which are specifically designed for it and I believe there are none currently in existence. Automobiles today use R134a and in the (distant) past they used R12. But no, you cannot ...
jwh20's user avatar
  • 12.1k
1 vote

My AC compressors won't run, and the systems won't take a recharge. What should I check next?

You need to get an AC manifold gage set and learn how to use and interpret it. It is dangerous for you and your vehicle to add refrigerant without knowing what the gage reads and interprets. In most ...
Jupiter's user avatar
  • 3,222
1 vote

Is it safe to vent R-1234yf to atmosphere?

TL;DR: R-1234yf is expected to evaporate in the event of a spill According to the Honeywell material safety data sheet (MSDS), R-1234yf is fairly similar to R-134a, with a few key differences: ...
Zaid's user avatar
  • 39.1k
1 vote

How much Pag oil should be added after recharging refrigerant?

It depends. If the refrigerant was lost with a slow leak, then most of the oil may still be in the system ("most" because you would have lost some changing the components out). If the leak ...
masospaghetti's user avatar
1 vote

Is 7% refrigerant loss per year worrying?

Yes , a leak is a leak . If the service information is correct. Efficiency falls as soon as you lose any refrigerant. And you certainly do not to need to lose all before the AC no longer works. My ...
blacksmith37's user avatar
  • 3,678
1 vote

What is the purpose of high pressure service port in cars ? Can we charge refrigerant into the system by high side service port?

HandyHowie is correct, kinda sorta. When you want to understand, really understand automotive mechanics you gotta start with a close look in your wallet. The #1 reason for the Air Conditioning (A/...
zipzit's user avatar
  • 6,539

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