I got my vacuu pump ($10) and gauges ($40) there too. good price and they work ok. the only problem i have its my compressor, only have a 20 gallons tank. not enough to use the vacuum pump. I cant never get the vacuum to the 29.9 in. mg. but i use the compressor at work 50 gallons tank. i get the 29.9 in. mg. in about half an hour. I see and heard people replacing A/C compressor and taking systems apart but have never heard anybody saying they replace Orfice tube at same time when they have the system apart. Its only few dollars and thats what makes the system get cold.

 

Harbor Freight isn't "pro-quality" but has always been adequate to get the job done w/o braking the bank over something I might only use a few times. Still, a favorite place to wander around on a Saturday afternoon! If I'm MIA on a Saturday, that's the first place anybody looks. They carry these little inline spark testers for a couple of bucks, that you can visually ballpark spark intensity & certainly differentiate a no spark condition. However, every one I've bought, has grown legs & wandered off. I think the only way I'll ever keep one is to give a bunch of em out as stocking stuffers this Christmas. A great place to pick up a Laser Thermal Reader to determine actual coolant/ Fluid/ bearing ect...temps or a cheap RPM Reader (for those w/o an RPM gauge or doubt it's accuracy)!

 

I normally do this as the screen gets clogged...good indication is in the gauges...dont forget the Dryer can get saturated with oil for those that insist you need to fill the system with freon with oil added...

For the Record...the OIL never leaves the system so adding more is stupid and can infact hinder cooling if too much oil is in the system...I learned this the hard way until I asked a professional long ago...I have also Hydrualiced a pump from too much liquid...I made a few mistakes back in the day but have learned much from it...

I do AC a little different than most but I get good results doing it that way...

 

I always blow out the lines with compressed air, every line. I assumed the oil comes out when I do that, I see some come out. Then usually you put on a new receiver/dryer, which requires a certain amount of oil.

 

no...the oil is for the compressor...and what it need will stay there...it doesnt need but i think 5 ounces.. the orifice and screen keep it suspended while running but the majority stay in the pump itself...the dryer should be clean of oil except for a film or the dryer cannot do its job...this is the part I learned the hard way...

 

This Haynes Heating and Air Conditioning manual goes on and on about this and that. It says to add so much oil for each component replaced. X amount for evaporator, X amount for condenser, etc. I used it as a rough learning tool to help me figure out what I'm doing. Usually it's the compressor that gets replaced anyways and I just add the amount the parts store tells me.

 

could be.. I never add oil...the compressors I use come preloaded...

I know too much oil and it doesnt get as cold as it should...but on a hot day even one blowing 50s still feels cold...

you can get them much colder if you experiment with other fluids..like Propane or Ammonia...

 

Oh yeah, propane gets COLD. When I'm on a sizziling hot roof torching it down and the bottle has ice on it, yeah it probably would do well in there. But I won't do it just because it's "not recommended".

I'm getting really tired of melting in my base model truck. All steel no headliner or anything is like an oven in this hot Florida sun. I'm about to start the search for a '95 134a truck to grab the a/c from. Then the a/c controls from an '87-'91 for my dash and make it work together. I'm just not sure if I need the under dash stuff too, if it's different on a non a/c truck.

 

you dont need to do that...just drain and switch...go to the auto parts store and get the conversion nozzles for the low pressure line to add the 134a the freon these days are compatible with the older oil...I have had NO issue what so ever and i have switched almost 100 older over to the 134a...I just drain and refill...as long as there is still some remaining of the old r12 there is no reason to vacuum...just fill it to the 134a pressure if thats how you fill it...

I still have a few mid 80s running 134a with no changes to the system...same oil and o-rings that came from the factory...

 

My truck is non-a/c. I don't want to put a R12 system on it because the 134a system will get colder than a R12 system with 134a in it.