73-87chevytrucks.com
General Site Info => General Discussion => Topic started by: Irish_Alley on May 21, 2010, 04:40:12 pm
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OK I have a 94 standard wheel base (swb) truck with a 4.3 need to know how much freon and what type of pag oil to put into a new system.
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R-134a PAG (Polyalkaline Glycol) synthetic refrigerant oil (GM Part No. 12345923) or equivalent.
2lbs of R134A
Your orifice tube will be in the liquid line After the condenser
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Are we talking about 46 100 or 150 pag?
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It's PAG 150 but you can use alternatives
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Well not sure what to after putting in the pag oil and guessing about 28oz of freon the compressor will kick on then it will shut off it keeps doing this I'm thinking like it doesn't have enough pressure to keep. Running so it shuts down then the pressure builds up and it kicks back on idk. But the pressure gauge is reading real high even shortly after I added the first bottle
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Well you are 4 oz short still and it is a CCOT system. Cycling clutch orifice tube. Do you have a manifold gauge set?
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Manifold gauge? I got the recharge kit from autozone that has a. Gauge with it. What's the ccot do?
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That little gauge won't tell you squat. A manifold gauge set is used to check pressures, recharge, evacuate etc. To prevent the evaporator from icing the low pressure switch cuts the current to the compressor coil to making it cycle on and off. The orifice tube drops the pressure making it drop it's temp. Make sure the pipe the orifice tube is in is insulated also or it will absorb engine compartment heat. Add your other 4 oz and see how it performs.
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Vile: Can you recommend an good inexpensive manifold gauge set (134a, but I guess I'll need R12 adaptor fittings)?
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http://www.harborfreight.com/a-c-manifold-gauge-set-92649.html
the fittings you can get at the autoparts store
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Thanks, I knew about that one, but didn't know if it was junk or not. The only other alternatives are $80+ sets.
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let me make sure this is right. I'll be going to my dads today to use his gauge and if he don't have it we will go to our old shop and use that stuff but the high pressure line from the compressor to the condenser is hot almost as if it was the temp of a heater core line not to hot to touch but uncomfortable and the low side from the evap core to the condenser is cooler not yet frosting over but cold to the touch same from the accumulator to the compressor does all this sound right?
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the evaporator is the coldest part of the system and the top of the condeser is the hottest part of the system
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Think I found out the problem what about the air in the system does it have to be pumped out or something?
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Yes you need to vacuum the system
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small little detail lol.
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my dad being hard headed don't seam to think you "need" to vacuum the system he being an old school guy that never went to school to be a mechanic just been doing it as a job for since i was a kid and but anyway think I'll sneak over to the shop and do it behind his back lol. what would cause the system to read full (low side in green about 40) only after adding once can of freon? you can head freon moving in the condenser but the low hose isn't cool anymore the high side is hot tho
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I'm not following what you are saying ??? Yes you do need to vacuum the system. Tell your dad since he's old school the old saying "do it right the first time" comes into play here.
http://www.aircondition.com/tech/questions/38/
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that was going to be my next question about the venturi pumps. i guess autozone used to rent out pumps but now they don't so if i cant get a hold of the guys at the shop i guess ill go to harbor and pick one of those up
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They're better than nothing but if the system has been open you really want to use a vacuum pump. You know any HVAC guys?
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One guy that hunts on the farm deals with that stuff ill try him thanks vile. I guess I never thought of home and car being about the same ideal
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OK vile its been a while but finally got the system working. After just dealing with the heat thought I suck up a little to the wife and fix the AC well took it to my uncle's shop and talked to him about my problem we start looking over it and my problem was the compressor would kick on and off very rapidly. So he hooked his gauge set up and saw my high side was way to high he said shouldest like a blockage. We looked over the system and told him everything is new except the evaporator. We talked about how the system works I learned allot the we talked about the orifice tube and how it works then I showed him were it was at and that it was facing the right way but then he questioned were it was at on the condenser. It was In The right spot but I had the hoses switched and had the discharge on the orifice tube and on the bottom. So took of home and did it right everything works nice and cool yet its only sitting at 30lbs but with the outside temp it should be about 50 so I might need to pick up a small bottle of freon. Thanks for your help on this vile
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Vile I've searched online can't seam to find it but what's the sensor that screws into the accumulator part # that I'm reading is gm52436358
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In the accumulator it would be the low pressure switch.