Automotive Vacuum Pumps for AC use

[Mike69cuda]

My old vacuum pump of 40+ years bit the dust. What should I buy to replace it? Amazon has single stage and two stage pumps? Do I need a two stage pump? Pretty reasonably priced, $75 - 200 for a good selection. I am a hobby hack, probably use it a few times a year.

 

[TT5.9mag]

I bought this one from Napa. Use it 4-5 times a year on my personal junk and work trucks. I don’t remember what it cost me but it works good.

Edited to add;
Just looked up the price, it’s $279 now.

 

[RustyRatRod]

Harbor Freight sells two nice ones. One for about 100 and one for about 150.

 

[Demonic]

Robinair is a well known name in the HVAC trade. JB, Fieldpiece are some others. The recommended practice is to change the oil frequently, especially if you evacuate a "dirty" system. Don't let moisture get into the pump. But as long as there's no leaks and a new filter-dryer, a china freight one might suffice.

 

[67Dart273]

Robinair is a well known name in the HVAC trade. JB, Fieldpiece are some others. The recommended practice is to change the oil frequently, especially if you evacuate a "dirty" system. Don't let moisture get into the pump. But as long as there's no leaks and a new filter-dryer, a china freight one might suffice.

WAS well known. Some of the lower end pumps are China. You might as well buy from Horrid Fright
THIS: is a China pump

 

[67Dart273]

A (funny?) story from the old days. My 70 440-6 RR had had "hang on" air added, ARA or something, with a large welded plate that bolted to the water pump bolts and a brace over to somewhere on the intake. In the early 70s, and fuel was going nuts, I swapped in a 340. THAT is a long story. One day I was "wishin" and it ended up drilling some extra holes in the 440 AC mount, and doing some clearance cutting, that thing bolted right on!! An we are talking hand tools, etc!!! So when it was time to re-charge it, and R12 was cheap, and no vacuum pump, I started out by warming it up good, as I knew heat would help drive out moisture and purged the system by blowing a couple of cans of R12 through the system, then evacuated it by USING THE ENGINE VACUUM!!!. As it pulled down, I would close the AC manifold valve, rev up the engine, then reopen the valve as the engine spooled down LOLOL

Hey, IT WORKED!!!

I was BROKE after the 340 swap. It later got some case rocker covers, Hedman headers, and I generally used a QJ or Holley spread bore carb.

 

[townsend]

Good idea using r-12 as a flush back in the 1970's, when it was dirt cheap. By the way, have heard that ebay no longer allows the sale of r12. Can anyone confirm this.

 

[volaredon]

Really?

 

[toolmanmike]

I have a air powered one. It runs my compressor to make it work but it is effective, inexpensive, and no maintenance.

 

[340sFastback]

I bought a Harbor Freight 120 volt vacuum pump been using it for around 10 years now.

 

[67Dart273]

Good idea using r-12 as a flush back in the 1970's, when it was dirt cheap. By the way, have heard that ebay no longer allows the sale of r12. Can anyone confirm this.

R12/22 are fully regulated. R134, unless it has changed, is available in small cans at ridiculous prices, and anything else is regulated, and THAT has become complicated because of the different license classes. I was actually thinking of getting re-certified after all these years to have access, at least, to R410a but I got mired in a mess of regulations and idiocy.

When I first got into HVAC/R sometime in the 80s, there was no regulation, yet, but it was being talked about. It was still done, in some cases, to just dump an R12 or 22 charge in order to change a compressor.

The tiny outfit I worked for, built several dehumidifier lumber dry kilns. Imagine a gigantic window air conditioner. Some of these used 80 hp shaft drive carrier V8 compressors, two of them used I think, 60 hp Micom shaft drive, screw compressors. One of them, the head mechanic improperly installed the suction tubing, which (I forget) was 2" or so copper, and the thermal expansion broke a joint open and DUMPED 250 POUNDS of R12. Back then it only cost the shop somewhere around 1.00-1.30 or so a pound.