A/C failure/rebuild saga, long post

Here's my story; '03 Pete 379 with 90" custom sleeper (Red Dot heat/ac unit).

A/C went "bi polar", good days bad days but was losing cooling ability. I made it home and tore the system down, even pulled the evaporator and condenser. I took the compressor apart and found 2 reed valves on the suction side broken off and 1 compression side cracked. Consequently the system is full of trash. Yes, the orifice tube was full of shrapnel and was installed backwards, no not me.

I've pulled all the lines with the exception of the sleeper lines. I flushed all the lines and evaporator with proper solvent and 180 psi shop air twice in both directions and captured 95% of the discharge. I'm getting a pale grey discharge which I assume is pulverized metal and even strained the discharge through cheesecloth resulting in a grey tint in the cloth. My big concern is I haven't collected enough metal to equal the mass of the broken reed valves. I did not flush the condenser as it will be replaced. I felt with all that tubing and elbows in the condenser I couldn't flush it adequately.

Have I missed anything????

New Parts List: Compressor, orifice tube, receiver/dryer, condenser, sleeper expansion valve and rubber sections of the lines. Of course, all new o rings.

Re used parts: Evaporator (flushed twice and cleaned with HVAC coil cleaner)

One question,, how much oil does the system need if the compressor is pre charged with oil?

 

Yes and no on the flush, I don't have the device you fill with flush solvent and spray it through the system. With the exception of the hi/lo lines to the sleeper I disassembled and removed the entire system piece by piece. Then, I poured about 2oz. of flush in each line and blew shop air through them, 4 times each. Ditto on the sleeper lines. I've blown at least a cup of flush through the evaporator.

Yes, I have a vacuum pump and the gauges, just not confident in my ability with the gauges.

Right now my big concern is where did all that metal from the broken reed valves go?

Thanks for the reply. I'll get it fixed, just trying to gather info. BTW, compressor tag says, "Pag oil 300 cc"

 

Thanks for the reply and vote of confidence.

Upon closer inspection the tag on the firewall says, "Pag oil 300 CC" , "Refrigerant 5.5 lbs." So with the new compressor (bought at Peterbilt) tag saying it's charged with 300 CCs of oil I should be good to go oil wise.

Yeah, shop air through a cheap filter is all I have for flushing. The holiday weekend caught me as far as getting the new rubber lines made up. I'll get those made Monday (7/7) and complete the assembly, pull a vacuum and let it sit overnight. If everything holds we'll charge the system and hopefully have A/C again.

 

Final Chapter. A/C BLOWS, lol.

Got my lines made Monday morning and spent the rest of the day installing everything. Then put on the vacuum pump, while it was "sucking" the system I cleaned up the install with zip ties and split rubber hose where chaffing may be an issue. BTW, I cut the old lines open, guess what? Clean as a whistle, oh well, peace of mind is worth something.

I let the pump go for 1.5 hrs. It did pull vacuum within a few minutes but longer is better,,,, right? Closed off the manifold, shut the pump off and left it overnight, came back this A.M. the gauges had not budged from 29hg YIPPEE! After a quick happy dance I got into charging the system. I've never done this before by myself but had seen it done several times. I even watched a few vids on youtube where one guy walks you through every step, very helpful. I don't have access to a refrigerant scale so I had to use the 12 oz. cans. At first, the compressor would only cycle a few seconds but with every can it would cycle longer and the vent temp started to drop .

Results: Ambient temp.,97*f, 1100 rpm, fan cycling, outside air into the cab, 52*f in the center vent. 1100 rpm, fan engaged, recirculate cab air 48*f in center vent.

Gauges: 1100 rpm, fan cycling; Hi Side - 175/295 then the fan kicks on. Lo Side - 22/44

I may have overkilled on some of the parts but I live by, " if there's ANY question, replace it with new". I have around $780.00 in parts and supplies, luckily I had access to the vacuum pump and gauges. Plus, I know some patient techs that would field my questions. Not to defend the shops/dealers so much but I hope you can understand that $1500 bill when you have to get your A/C fixed.

Thanks everyone that responded and viewed, K. Lee

FYI, for those that have Cat engines (mine 6NZ) be sure to check the A/C mounting bracket. It's a big aluminum casting that the A/C compressor mounts on between the fan hub adjuster and the alternator. Mine was cracked and I wondered why I had to adjust my belts so often, lol. $101 at Peterbilt, not awful, I was expecting twice that.