mudslut28 Posted April 12, 2008 Share Posted April 12, 2008 I dont know how it happened but I quit asking questions like that a long time ago but my R Model has been sitting for a couple of weeks and somehow the a/c compressor has managed to lock up while sitting. I thought it was weird that the truck wouldnt start when it will usually start on first turn anytime. Well I boosted it and started and it was locked up tight belt squalling and all. Only in trucking could you ever have stuff like this..lol. Anybody know what kind of compressor this is and approx cost? Its on a 92 RD688SX 400 Mack motor. Last 5 of serial # 12274. I cant live without my a/c...lol. Thanks in advance!! I wondered why but seeins how it is 16 years old theres a good chance its worn out...lol. Quote Link to comment https://www.bigmacktrucks.com/topic/3619-ac-compressor/ Share on other sites More sharing options...
ciw65 Posted April 13, 2008 Share Posted April 13, 2008 Not sure about the original item, but I replace them with Sanden SD-7 compressors. They make a generic replacement for all different types of hose fittings. In Aus they are around 300 - 350 AUD. However, your problem sounds like the pulley bearing has seized, which can be replaced without de-gassing the system reasonably cheaply. Quote Link to comment https://www.bigmacktrucks.com/topic/3619-ac-compressor/#findComment-18278 Share on other sites More sharing options...
mudslut28 Posted April 13, 2008 Author Share Posted April 13, 2008 Not sure about the original item, but I replace them with Sanden SD-7 compressors. They make a generic replacement for all different types of hose fittings. In Aus they are around 300 - 350 AUD. However, your problem sounds like the pulley bearing has seized, which can be replaced without de-gassing the system reasonably cheaply. Thanks Chris. The main thing I didnt wanna do was discharge the system. The a/c worked very well. The clutch on it still turns freely.....the pulley just wont turn. This a/c repair is completely new to me..I used to just not worry about em. How would you get the pulley off of it? I havent really even looked at it very closely or started on it yet. Was just sorta disgusted when I seen it was locked. Quote Link to comment https://www.bigmacktrucks.com/topic/3619-ac-compressor/#findComment-18297 Share on other sites More sharing options...
Rob Posted April 13, 2008 Share Posted April 13, 2008 Thanks Chris. The main thing I didnt wanna do was discharge the system. The a/c worked very well. The clutch on it still turns freely.....the pulley just wont turn. This a/c repair is completely new to me..I used to just not worry about em. How would you get the pulley off of it? I havent really even looked at it very closely or started on it yet. Was just sorta disgusted when I seen it was locked.Sure wish I were closer to help you out. Is it a "York" style compressor, (twin cylinder reciprocating), or an axial Sanden design? If it is a Sanden, the clutch driven plate is retained by a bolt through the center into the compressor crankshaft, and the magnet/sheave assy is retained to the compressor hub with an external snap ring. Also, dont try to run a Sanden with the pulley froze up. If the body spins on the stub it mounts to, the compressor will be junk! The system does not need to be dumped in either compressors' case. Clutches for either unit are about $100.00, (or so), but I don't think you can purchase just parts other than the magnets separate from the whole assy.Unless you have a known very sound system, I would go ahead and pull the refrigerant out and replace the orifice tube or expansion device, receiver/dryer/filter, "O" rings, blow the entire system with clean, dry compressed air and recharge with R-134A after a four hour pulldown to at least 500 micron. Any compressor with age on it puts trash into the system. Being a 92 model year it will still have R-12 refrigerant unless it has been converted. Oh yeah, use about 7 ounces of "ester", or "PAG" oil per pound of refrigerant the system requires for lubrication. These are both compatible with R-134 where mineral oil is not. Unless it has been done previously, acid clean the out surface with a high foaming coil cleaner. I like Alki-Clean readily available from Grainger. A bug sprayer, or spray bottle works well for usage, just wear rubber gloves. If you don't, you'll wish you did!It's not near as hard to do the job right the first time than to redo it later!Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/3619-ac-compressor/#findComment-18298 Share on other sites More sharing options...
HK Trucking Posted April 13, 2008 Share Posted April 13, 2008 The Macks that I had of that vintage all had Sanden A/C compressors, so I'd bet that's what it has. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/3619-ac-compressor/#findComment-18303 Share on other sites More sharing options...
ciw65 Posted April 13, 2008 Share Posted April 13, 2008 Let me know what brand compressor it is and i can pm you the instructions for pulley bearing replacement. Is reasonably easy, you just need a puller that will use 2 5/16" bolts to pull the clutch off the shaft. As I said no need to de-gas. Quote Link to comment https://www.bigmacktrucks.com/topic/3619-ac-compressor/#findComment-18304 Share on other sites More sharing options...
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