AC overhaul - Compressor upgrade? Condensor?

BowhunterBrown said:

High Side Port

On another note, I will be replacing the high side port this next go around. I did not replace it with this last winters overhaul (didn't realize you could remove it) and I suspect it might have tiniest of leaks. I can just barely hear a hiss of pressure when I remove plastic cap.

My question is do I install GM part with black rubber ball valve, or do I install the Dorman part with standard schrader valve?

Note, I even picked up the proper socket for the job. Mastercool 98234

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I will only use the Dorman and refuse to use the nylon ball garbage. I had an OE replacement fail immediately numerous years ago on the Tahoe. After the high side was opened by the manifold set while vacuuming the system it failed to re-seat.

Since we are on the service fitting topic, on R134a retrofit fittings I use the steel fittings designed to thread on the R12 fittings with the shrader cores removed and also use a little blue loctite on the threads to promote sealing.

1998_K1500_Sub said:

I didn't know they made such a thing

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The GM parts are inexpensive, I think I last paid $6 for one. The Dorman w/ replaceable valve may be more reliable (?) and easier to service, when/if service is necessary. Read on...



I wonder if that tool would work on the replacement high-side service fitting that you showed in the prior post.

My take: Keep the service fittings capped when not in use and inspect/clean the service fittings before making connections. Dirt that may get lodged in the valve (or in the refrigerant for that matter) will not be your friend. Tight caps on the fittings provide another barrier to leakage.

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Yes, the tool set includes a high side tool as well. But as you hinted at, it would only work on the Dorman style schrader port not the GM ball valve port.

I have come to that conclusion too regarding keeping the ports clean. I think I probably botched my valves from gritty gauge service fittings. I am thinking it would be a good idea to apply small amoount of pag oil to the gm ball valve, before attaching gauge fitting, but I think I am going to go with the Dorman schrader valve style here on out as L31MaxExpress suggested.

BowhunterBrown said:

I have come to that conclusion too regarding keeping the ports clean. I think I probably botched my valves from gritty gauge service fittings.

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I've watched guys in repair shops simply roll the Robinair machine over and connect their mating fittings (which had no protection from the dust of the shop environment) to the fittings on a vehicle, without a moment's consideration for cleanliness of any of the fittings.

OK, whatever...

I don't like to let other shops touch my AC, or my vehicles in general.

Good stuff here! A note on parallel flow condensers - if the in-feed and discharge tubes are on the same side, it's probably a 4-pass system. It can be more or less but it has to be an even number. If one connection is on one side and one connection is on the other, it's an odd number of passes. Just saying

1998_K1500_Sub said:

I don't like to let other shops touch my AC, or my vehicles in general.

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Same here. I don't like letting anyone else touch my rigs. Getting a handle on AC systems has been a big step on gaining that personal independence from shops. It has been a lot of work, research and money, but I am learning a ton along the way, and haven't dropped a dime on shop labor or marked up parts.


All that said, I was careless and just slapped my gauges on after they gad been sitting in my filthy garage. They are oily and attract all the dust, dirt, grit and hair. One of the things learned along the way I guess.

L31MaxExpress said:

I wish the aftermarket would wake up and make a larger version of this condeners. It is unfortunately only 12" x 21". This unit is a microtube parallel flow subcooling design with a built in liquid tank receiver dryer. Seperating the gas from the liquid and further cooling the liquid refrigerant by the last pass provides a noticeable efficiency increase by ensuring the expansion device is only getting liquid refrigerant to expand into cool atomized boiling liquid. FWIW if I were manufacturing condensers this would be the only way I built one for any application. The added desicant would also effectively double the moisture handling capability of the system.

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Think it would be feasible to favlb this up at home? Would it be as simple as welding a capped tube to the condensor with a few ports for exchange?
I know a guy next town over that us pretty good welding uo aluminum. If it's that much better performing, seems worth trying.

In theory, would this subcooler type condensor work plugged into a gmt400 chevy with stock accumulator left in place or would other modifications to the system be necessary?

Some ongoing questions I have:

1)
When to replace dryer/accumulator? Anytime replacing parts or is it fine to leave if system not exposed to moisture between part changes?

2) is it fine to mix pag 150 and pag 46 in a system or is complete system flush necessary.

3) choosing the best orifice tube for your application. Variable versus fixed? Large orifice versus small?

BowhunterBrown said:

Think it would be feasible to favlb this up at home? Would it be as simple as welding a capped tube to the condensor with a few ports for exchange?
I know a guy next town over that us pretty good welding uo aluminum. If it's that much better performing, seems worth trying.

In theory, would this subcooler type condensor work plugged into a gmt400 chevy with stock accumulator left in place or would other modifications to the system be necessary?

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The accumulator stays in place just like they had factory. The only adjustment would be charge volume.

L31MaxExpress said:

The accumulator stays in place just like they had factory. The only adjustment would be charge volume.

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Seems doable then. Assuming parallel flow would be the way to go with adding this sub cooler. Stabdard or micro tube necessary to take advantage of the subcooler?
So is there just a stash of desiccant screened off up in the top of tube?

BowhunterBrown said:

Seems doable then. Assuming parallel flow would be the way to go with adding this sub cooler. Stabdard or micro tube necessary to take advantage of the subcooler?
So is there just a stash of desiccant screened off up in the top of tube?

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I do not see a way to convert a standard parallel flow condenser to a subcooling unit without cutting it open and adding an additional baffle to block the flow into the new chamber. The integrated receiver dryer typically has a screw on cap with a filter screen built into it and a dessicant pack jammed into it. This is a replacement dessicant pack for an asian vehicle. Did not even look to see which one as they are all basically the same. They typically ship in a plastic bullet shaped tube pressurized with nitrogen with the cap threaded on the end.



If you are good at tig welding aluminum and fabrication I would love to see it done though. I would love to see the end results because I feel like they would be a substantial improvement. Denso claims their 11mm microtube parallel flow subcooling condenser is 45% more efficient than a standard thicker parallel flow condenser for the same core height/width. I cannot help but think it might actually be easier to find a suitable dimensioned Denso condenser for a Toyota or Nissan or other Asian vehicle, cut the fittings off and install the R12 or R134a threaded fittings in place of the oring single bolt flange style fittings.