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AC orifice tube location

orrum

orrum

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Orrum North Carolina
I am rebuilding or flushing the stop leak on my truck and thr ac retrofit manual is unclear as to the location of the orifice tube. The guy at the auto parts and the guy at a ac shop both gave me different answers. My truck is a 1991 GMC 3500 dually with a 6.2. Jump right in Acesneights since u inspired me last year to do this. Anhbody else jump in please. Sorta gotta find out quick cause I got it flushed and unplugged and need to put it back together before it gets a lot of moisture in it. No I did not get back on the forum to take ad antntage of u greasy sooty black handed folks skill set....but I need yall. Hey I did put the starter and brake lite switch in without yalls help!
 
On a 91 it should be in the line going into the evaporator. When you take the high side(smaller line) off at the evaporator, look inside the evaporator and you should see it in there. It will be recessed back in slightly, and is a real PITA to get out. I found a small 45 degree pick works pretty good. I would put a variable orifice tube back in it since it is a retrofit, and if the threads are messed up on the condenser, swap it out for a 94+ unit.
 
Thanks a bunch. I think the ac shop took it out last year when they tried to get all the stop leak out. I can push the orifice tube almost all the way in but how far is all the way in since u say its recesseded in there? Could the old one still b in there? The parts place guy said the fins on it would fit down n a notch and I would be able to feel it, I cant feel it. How did u know the threads look bad on the condenser? How would u get the thing out if u didnt have the accumulator drier off and out the way? My olds had it in the condenser.
 
R-12 systems in the trucks normally have the orifice in the evaporator core, R-134 moved it up by the condenser. The condenser thread problem is if you have to take the lines off of it and the threads come off. A regular orifice tube will sit just about flush with the end of the pipe going into the evaporator when it is installed all the way in.
 
Once again thanks, real good info. Is it possible I have a 134 condenser since it looks like it has a place 4 one in the codenser? It
 
Oops sent early. Should thr screen end go in first or the white plastic end with the fins? If I have a newer condenser should I put a orifice in both places??
 
You use only 1 orifice, if you put 2 in it you will have no air and EXTREMELY high side pressure. If you put it into the evap, the screen side should be facing out to filter the refrigerant before it passes through the orifice.
 
Ok I think I can do this. I flush it then put on seals and lubricate them n put ester oil in and put all together and take 2 the local shade tree and he pulls a vacuum to 29 n if it holds we vac for a hour and add 36 ounces of 134a n cross fingers and hopefully all is clean n dry n I Have cold ac!!!!!!
 
orrum said:
Ok I think I can do this. I flush it then put on seals and lubricate them n put ester oil in and put all together and take 2 the local shade tree and he pulls a vacuum to 29 n if it holds we vac for a hour and add 36 ounces of 134a n cross fingers and hopefully all is clean n dry n I Have cold ac!!!!!!
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Pretty much. Flush it out as best you can and get as much of the old mineral oil at as you can. Put 2 onces of oil in the drier, 2 onces in the condenser, and 4 onces in teh compressor of ester oil. Vacuum it down, and then charge it back to 75% of the R-12 capacity with R-134A and see how it's working. It will hold roughly 75-85% of the origanal R-12 amount with R-134A.
 
Good to have you back orrum!!!.

A bit over a year ago I replaced my AC pump, condenser, and drier. Being on a limited income I did as much as possible myself. The AC guy had me use denatured alcohol to flush the lines and the part inside the dash (evaporator?). I used some flex line as a funnel to get the alcohol into everything, then let it set for a while. Then I used compressed air to blow it all out. At this point be careful as the stuff that came out was a horrible black and sticky junk. Since I wasn't prepared for that it blew all over everything in that area and left a mess.

Good luck with your project.

Don
 
Hey Don its great to be back! Thanks for the advice about the gunk getting everywhere. I only got pink colored alcohol out of mine but its everywhere! LOL But hey I Might get cool at the end n if not I sure got edumacated!
 
Doing great! Fixing to take offn my old truck n go visit all of thr USA! Gonna need a lot of layovers at friends houses. I have a slide in camper and two horse trailer full of veggie oil! Experimental truck runnin on experimental fuel, shooting for 6000 miles total travel.
 
Hey Fermanator I got it put back together!!!!!!!! Orifice was challenging, got it way in and felt the grooves and pushed a lil harder n it went almost all the way in. Then I put the line on and the line pushed it the rest of the way, I Hope its ok! Got the rest all put together and tightened up to avoid moisture in my new accumulator pretty fast. Next step is to get the transmission auxillary cooler installed and put thefron end on. Then take it to my friend the shade tree mechanic and get a vaccuum pulled and charge it and pray! I hope it works!
 
Fermanator I bombed! Pulled a vacuum for a hour ar 29.something n turned it off and it held with no loss so we put the freon in and nothing.....Nothing at 24 ounces, nothing at 36 ounces and tried 48 ounces. Compressor kicked in off and on while putting freon in but once we were finished with a can it would quit trying. Pressure a lil over 200 on high side and about 60 on low side. Jumped it with a paper clip to keep compressor running and still no cold air. 400 dollars and a years work and no ac! I am not disgusted but getting pissed at the problem. Got pissed at a horse pasture about 20 yrs ago cause I couldnt find a short in the electric fence on top so I hooked a chain to the fence and the tractor and drug the whole thing out into the hay field and took a weeks vacation and built a brand new fence. LOL Cant afford those stunts no more. Have u or anyone else got any ideas?
 
Your pressures don't sound to far off fro mwhere they should be at. Sounds like a restriction somewhere though to me. Are you sure it doesn't have an orifice in the condenser too? Most replacement ones have one in there that your supposed to pull out for the early trucks. And if you could, post up a pic of where your guage hook-ups are at. The low pressure switch shouldn't cut out until 18-20.
 
Went to ac shop today. No go wont work. He moved the orifice to the condenser because it goes there. He said thry vary. Hd put freon n and drew it out and watched the gauges n he said its stopped up and he said he cant say if its the evaporator or the condenser. He thinks the compressor is good. He said he really thinks the condenser is stopped partially. So I went to another friends shop and got a condenser out of a 96 gasser. Took it to the ac guy and he took the orifice out of it and said the orifice looks good. So Went to the Napa store and got a new orifice and to the grocery store and got a can of scrubbing bubbles. Then back home to flush the things insides with denatured alcohol and outside with the bubbles. Letting it dry out overnite and then gotta comb out some smeared over spots. Then back to the ac shop at 1 pm tomorrow n he is going to pressure flush it and we r gonna put it onbin front of the other one and see if I have ac. If it works he will pull the freon out and I swap them out and take it back n he puts the freon in and we done. This is killing me! LOL USING A LOT OF MONEY TOO! Outlaw stopleak!!!!!!!!!!!
 
orrum said:
Hey Fermanator do u run a repair shop? Maybe I oughta make Zephrhills a stop on the trip! LOL gotta look up ur location.
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Not an actual shop per say, but I do a fair amount of work out of my house. I'm disabled and work out of my garage when I can to pay the bills. A/C is one thing that I'm pretty good at, and make a fair bit of money on during summer.
 
I am disabled too. Not because of the leg being amputated but because of the damage done to my organs etc by the antibiotic resistant staph. Long sad story. Don is disabled too. Do u know him? Looks lk
 
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