How hard is it to replace A/C system?

[j.edi]

[1995 2WD Sierra 1500, 6Cyl. VIN Z]

I need to replace my A/C system, it has been empty and useless for a couple years now.

I can't afford what my mechanic wants to charge, and he said I shouldn't attempt to do it myself. I think he just wants all my money... how hard is it, really?

Sure, I'm not ASE certified or anything, but I can certainly remove broken crap and replace it with new stuff. What could go wrong?

 

[Biggershaft96]

Just be sure the system is actually empty and not just bad refrigerant. That **** will choke anyone out in a hurry. If it were me i would find the source of the leak or leaks and replace those parts. Anything to do with the A/C is pretty pricy brand new. As far as difficulty, as long as you have all the right tools its not bad.

 

[j.edi]

oh it's empty alright. compressor sprung a leak so big I could charge the system and have it last 2 days, spraying crud all over the bottom of the hood while it bleeds out.

 

[Biggershaft96]

oh it's empty alright. compressor sprung a leak so big I could charge the system and have it last 2 days, spraying crud all over the bottom of the hood while it bleeds out.

I would just replace the compressor then. There is a upgraded versions somewhere, ill se if I cant find the part #.

Edit: Its a sanden u4440 but I'm not sure if it will work with the tbi engines

 

[chipskittles]

TBI is pretty much stuck with the Harrison R4 compressor. Do NOT waste your time and money on a rebuilt one, you will regret it. Amazon has the factory Delco new compressors for a not outrageous for a brand new a/c compressor price of $200. If you want the new one to last awhile you will want to change the condenser and orifice tube as well. If you can get the receiver drier off that's a good thing to change too but the lines tend to weld themselves together. Compressor will need the right viscosity of PAG oil I don't remember which kind right now but it's a search away.

 

[Blackwater]

I bought a reman and snow flakes shoot out the vents. but I also replaced everything except the inner core. I flushed it. It was R12 until the compressor locked up spewing refrigerant out the hood and burning off the belt I put on the week before. If you still need help let me know you can do this yourself if your sing R134a

 

[Knuckle Dragger]

At a minimum you need to replace the compressor, dryer and orifice. Given it's just a leak you should flush the system but it's not 100% necessary. You will need to have the system completely evacuated and not just a quicky job. I'd let is sit on vacuum for a good hour given the system has been open so long. And then of course it has to be charged.

As mentioned earlier the dryer is a ***** because the threads seize. Be really careful on and off, but changing it isn't an option. The system is full of moisture and the descendant bag has absorbed all it can.

The orifice can be changed by pulling the right turn light and working gently on the line. Go all cave man and you'll induce a leak at the condenser. No need to replace the condenser unless you had a catastrophic mechanical compressor failure and you can't get it to flush clean.

Pay attention and work clean. buy the right o-rings, not just what autozone has in stock or what's easy to get. Coat all the o-rings with A/C oil and be careful not to cut the rings on install. There are lots of little things the DIY guys can mess up, but if you pay attention and use common sense you'll be fine. Don't leave the oil open when not in use. It's hydroscopic and will be ruined in a few hours.

Reman compressors suck ***. I will not install them on my own stuff. They are failures waiting to happen. I know we'll get stories about how someones reman lasted forever yadda yadda yadda, but that is not the norm. I personally only buy factory quality compressors. Delco or Denso would be my suggestion. I'm sure you would rather do this once and not every year, don't cheap out because of a few stories where the guys got lucky.


ASE master tech for over 30 years.

 

[Blackwater]

I would like to add to Knuckle draggers post. I used a AC Delco Reman. Not a knockoff brand. I also had two ASE master mechanics advise me for free, (perks of being a veteran in a MWR Auto Crafts shop) when doing this. When my compressor went out I had to limp it 30 miles down range to the nearest Auto Zone. I knew I needed to change to 134a therefore I had to change the drier and hoses, evap and orifice tube. I flushed the evaporator extremely well. Added Pag oil directly to the compressor as specified by the manufacture. Lubed all O-rings before install. Used the shop's automated machine to vacuum and charge they system. when I was advised to put 10% less R134a then what was recommended for R12. I could have reused the condenser but the fins where closed off so much that I felt there wasn't any airflow. When I was finished you can see the accumulator was frosting. That was almost 5 years ago.

This year I noticed there wasn't any cool air from it. Found a bad R12 to R134a adapter. It was leaking a little and wouldn't allow any refrigerant to go in. Replaced and added 16 ounces to it and back to frosting the accumulator was frosting again and the compressor cycle times where longer and longer as I was filling. Cold air returned.

Those same ASE certified techs told me that the ASE test is just certifying they know basic knowledge of a vehicle. They told me to do it for kicks. I been too busy ENGINEERING electrical systems, building integrated circuits designed to detect microwaves at intense power and reworking hydraulic, pneumatic and electrical actuators. This year since I will be slowing down I may take a mechanics course for grins and giggles. I have several truck projects and one special car that I am building from scratch for my wife.

Remans are ok depending on who remanufacture them. It is not weather its a new part or reman part. Its the care that the reman company puts into it. I do not wish to start a fight on here, I want to see good info. I think 5 years on a Delco reman is doing good for the price I paid. It also could be the care and pride that I put into rebuilding it. Paying attention to detail of what I was doing may also contribute to the long lasting of my reman AC Delco.

Due to inflation, there is my $2.75.

 

[7echo]

On the Rock Auto site the AC Delco compressor is $170, the 4 Seasons is $160. I think these are new compressors. In the past I seem to recall they had re-mans for sale as well but I do not see them now.
I am not sure how cheap you can get a re-man but I plan to go with a new compressor, condenser, accumulator, and hoses. And since it was mid 70s today I need to get the parts ordered and work done pretty soon!

 

[1995z71]

I would go with a new ac delco compressor if money allows... I've been through 3 reman compressors through o'reillys and its not worth the hassle even if its under warranty. As others stated I would keep it under vacuum for an hour and monitor levels for less of a headache... just my 2 cents