New to DM. Going to change an a.c. compressor tonight. Is there one available? Also, Am I able to pull a Honda inside? Do I need a reservation?
The vacuum for AC work is a venturi type. It is red plastic, 6-8 inches on a side. It should be on the shelves next to automotive.
The bays are generally first come first serve. The rules are posted up high on the shelves to the south of the two work bays.
That isn’t for pulling vacuum in A/C. I don’t believe we have one.
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Yea, doesn’t look like one I’ve ever seen. I hope autozone rents one…
That is the one Allen used to pull a vacuum when he was teaching automotive AC classes.
I haven’t used it before but Harbor Freight says
This air vacuum pump is ideal for automotive air conditioners, home air conditioners, refrigerators and freezers. The air vacuum pump is a venturi-type AC pump that eliminates moisture from air conditioning systems, making it safe and easy to add refrigerant. The air vacuum pump is easy to operate and pulls full vacuum within two minutes of being connected to an air line.
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Sorry, my mistake…
Autozone will loan you one, with a deposit on your CC for the full price. When you bring it back, you get a refund.
Wouldn’t be a bad add for the Automotive committee to have a single-stage. They are anywhere from $175-300.
[edit] Also, a nice set of R-134a gauges would be nice.
chuckle “Full vacuum”, eh? I suspect that is for various values of “full”. 
— Zach
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HF claims 28+" Hg. I don’t really believe that.
The one I own works as advertised provided it’s hooked up to a compressor capable of sustaining the required supply of air. It quickly and easily draws down to -28psi on the A/C gauge, same as the old electric single-stage I used to use professionally. For occasional use, it’s hard to beat. If you’re going to use it frequently, investing in a good electric unit can help save your air compressor from the not-insignificant load and the rest of the shop from a shortage of compressed air. Hardly seems like a challenge for the new compressor, but if everyone is frivolous…
Many shops have used that for years. Run it a minimum of 3 minutes (was 15
minutes in the old days if you want to wait). The longer the better.
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Is any of you master mechanics around DM today that could help me recharge my AC system on my Prelude? I just changed the compressor, dryer, and expansion valve. The Alldata info says the things below, but was stuck on whether for the oil I add up all the figures if I’ve flushed the whole system, or if I just use the 4.5oz that came in the compressor and that’s the total amount the system needs? I’m heading up there now to do some other things, and will bring all my hoses and gauges if anyone is around that could help me. I’ve done it before, but a long time ago. Don’t want to screw it up. I need to evac and leak check also.
Refrigerant capacity: 750 +0/-50 g (26.5 +0/-1.8 oz) = Two cans? or Three?
Condenser 25 ml (0.85 oz)
Evaporator 40 ml (1.35 oz)
Line or Hose 10 ml (0.34 oz)
Receiver/Dryer 10 ml (0.34 oz)
Leakage Repair 25 ml (0.85 oz)
Compressor 130 ml (4.40 oz)
Note: Volume of old compressor should equal oil drain from new compressor, but not more than 50 ml.
Anyone? Bueller? I’m here in the Common area. Any help?
Text me at 8178750663 and I’ll meet you in there is you can help me!!
I have a good vacuum pump that I could loan to DMS…it is currently residing in my storage unit, for use on that odd occasion that I do AC work…I’ll bring it up next time I am up there…is there a process for loaning that item?
Basically here: https://dallasmakerspace.org/wiki/Rules_and_Policies#Loaning_of_Tools_.26_Equipment_To_The_Makerspace
(there’s a small issue with these instruction since Ops split in half, but we’ll fix the instructions “soon”)
Ok, so I am here, and I have brought the pump to put on loan. I have cleaned it up, put a new cord on it, and verified it works. Is there somewhere I should put it? @Brandon_Green
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Sometimes, when it has sat for a long period of time, it will seize.
To get it going, just loosen the Phillips head screws on the head and then plug it in and then tighten the screws down. Please take care not to strip the heads. They don’t need a lot of torque.
There needs to be oil in it, and it uses plain air tool oil. Note the level, it doesn’t require much oil:
