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  1. #1

    Default A/C clogged...Where's the Orifice Filter on a 98 GMC?

    I'm fairly sure that the system is clogged from what I'm seeing from the gauges. Plus it's fully charged and pumping but blowing hot air. The high side is getting way way to high. I purchased a new orifice tube. I haven't worked on this particular truck before. It's my dad's 98 GMC 1500. At least I think it is. I still need to pick it up sometime this week. Where the heck is the orifice in this truck? I've always worked on cars with expansion valves up in the dash. Any info would be great. Thanks.


  2. #2


    If i remember correctly it in the low side just out side the dryer. Youll see a gold colored connector where the 2 lines are different sizes. Open up that connection and the orfice tube will be in the smaller of the 2 lines. Be sure to properly recover the r134 and have it recharged professionally. If you have the system open for longer than 10-15 mins or live in a high humidity area and mabe just because its an older truck you should replace the dryer at this time too. It will only help in your quest for a cold a/c system. Also if you open it all up and you pull the old orfice tube out with some needle nose plyers and you notice small aluminum peaces in the tube you have a problem. Your compressor took a ****. At that point its good to flush all lines individually, including the condensor. Replace the compressore, orfice tube, dryer, and again have it charged also i always add alittle bit of die in the system just incase later on i get a leak it makes it alot easyer to diag. Oh and DONT forget to install the correct amount of oil, and make sure its the right weight of PAG oil too. I hope im not to late, lol.
    2005 Chevy Silverado - Bright orange, 4.8L, 2wd, reg cab, short bed, Stock for now. :glasses:
    1967 Ford Mustang - Coupe, 200ci 6cyl w/minor upgrades, Stereo, Wheels, Interior, All other stock. White. First car and love her.

    Former cars.
    1967 Ford Mustang - Coupe, 302 race prep, one bad ass car but she met her maker at the track :erf:
    1997 Ford Mustang Cobra - All stock, caused to much trouble with her. Well thats what the cops kept saying so i had to get rid of her.:grrrrrr:

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