A/C compressor upgrade.

[Twisted Steel Performance]

The switch in mine, a white one, isn't adjustable, yes it does work but the other one works much better. I didn't know this stuff, my ac guy did.

 

[FellowTraveler]

If you're switching to HC based refrigerants, it's best to install a temp cutout probe directly into the evap.

BY HC you mean Enviro Safe, or? If so which probe and temp you suggest?

 

[Will L.]

HC is HydroCarbon as in propane based refrigerants which 25 years ago was way to dangerous and would cause way to many burn victims from evap leaks in the cabin.

But now its ok. Not that less people will get burned or not that anyone gets burned less severely. But now the spotted tree polar bear tortious’ life is more important than yours.

Btw, the US military is still the he #1 consumer of r12 just like they have been since the early 70’s. Any aircraft mechanics here like my dad was that wants to explain why they vent all the r12 directly to atmoshpere? Cleaning what? Haha

 

[FellowTraveler]

HC is HydroCarbon as in propane based refrigerants which 25 years ago was way to dangerous and would cause way to many burn victims from evap leaks in the cabin.

But now its ok. Not that less people will get burned or not that anyone gets burned less severely. But now the spotted tree polar bear tortious’ life is more important than yours.

Btw, the US military is still the he #1 consumer of r12 just like they have been since the early 70’s. Any aircraft mechanics here like my dad was that wants to explain why they vent all the r12 directly to atmoshpere? Cleaning what? Haha

No less dangerous than say ammonia..........I suspect.

 

[THEFERMANATOR]

Yep, the enviro safe and others. Many have had problems with the evaps freezing over using just a low pressure cycling switch. I know a few of them even recommend to run s temp cutout switch. Mercedes, Volvo, Jeep(in the late 80's), Dodge(in the 80's), and I'm sure several others used temp probes in the evap to cycle the compressor.

 

[FellowTraveler]

Yep, the enviro safe and others. Many have had problems with the evaps freezing over using just a low pressure cycling switch. I know a few of them even recommend to run s temp cutout switch. Mercedes, Volvo, Jeep(in the late 80's), Dodge(in the 80's), and I'm sure several others used temp probes in the evap to cycle the compressor.

I like the idea of a temp probe cutout in the evap (I did have that type of freezing issue) just have to find one that will complement my Fummins mid mount compressor setup to the existing AC components.

 

[WarWagon]

I had one of the variable orifice valves in my truck until the previous R4 compressor sh$t the bed. Blew trash all through the system, but I flushed it out real well and put on a new condensor. Easy to see why you can't flush a condensor anymore. They all seem to be parallel flow, not serpentine. That VOV did help the cooling at idle with mine also, but I had to get the truck back together and no auto parts store had the VOV in stock. Put the standard orifice tube back in. Do you have a link, War Wagon, for someplace with the 11 CU R4 compressor? I'd appreciate it. Good interview with Mr. Kozinski also. Thanks.

A 1995 Dual Air Suburban should be a 11 CU compressor. However parts suppliers on the way past the bottom of the barrel for CHEAP, CHEAP, CHEAP!!! May have consolidated on a smaller CU size compressor part number. Parts stores have done this on the belt tension assembly using too weak of a spring for 1995 and older as it fits the 1996+ with a weaker spring spec, engine mounts that won't fit a 6.5 diesel...

Keep in mind the port height for the suction and discharge on the compressor: it's different for R12 and R134a units. You use thicker sealing washers in a kit to make it work. This is a weak area that will blow out before the relief valve opens. Yeah, look at old compressor and new compressor because 1993 is a FUBAR year for that. I never know if the compressor is R134a or R12 ports and neither does the parts counter people.

1995 dual air burb is for sure R134a ports. Well, should be.

Again I would love to see a Sanden conversion as the last one I took off was a Dodge OEM 2003 with 150K on it. High head pressure from a slow to respond (old) fan clutch took out the compressor clutch finally. And , Well, I have always wanted to see it done on mine.

 

[56pan]

Ok, now that I know the Suburban application, I'll start shopping around for the 11 CU R4. Thanks very much for the help, sir.

 

[Twisted Steel Performance]

I just had my dually fixed, i asked my ac guy and he did not recommend it, said it makes the system cycle too fast.. i do know my ac will freeze us out now, new r4 and dryer, and 47oz of charge..

 

[WarWagon]

I just had my dually fixed, i asked my ac guy and he did not recommend it, said it makes the system cycle too fast.. i do know my ac will freeze us out now, new r4 and dryer, and 47oz of charge..

Your AC fellow has a point. Keep in mind my advice is in Phoenix, AZ where 121 degrees is the high and 105+ is the norm. It's now monsoon humid with the high heat. (Dry heat jokes are a lie.) Unless you run the blower on something less than med-high all the time the cycle time is not relevant. Idle is where the larger compressor helps and the overriding concern is keeping the condenser from overheating. Frankly: Compressors are expendable here and expended often.

Given the choice between a oversize 11CU compressor and a coated condenser I would recommend the coated condenser. Further idle performance can be improved with "high idle". This is raising the engine RPM someway somehow to 1100 RPM. Even 750 cold idle speed helps. More fan RPM and more compressor RPM.

Moving the heat is one thing, but, getting rid of it is the most important goal.

 

[Manson-Hing]

Decided to do this upgrade on my 95 Sub and cant figure out the bracket placement. The instructions that come with the bkt kit says to discard air pump and the factory bracket pictured doesn’t match what I have. Any suggestions and what am I missing here?

 

[WarWagon]

Decided to do this upgrade on my 95 Sub and cant figure out the bracket placement. The instructions that come with the bkt kit says to discard air pump and the factory bracket pictured doesn’t match what I have. Any suggestions and what am I missing here?

The bracket is for gasoline engines. Not for Diesel engines. Vacuum pump on the diesel vs. AIR pump on gas...

 

[Manson-Hing]

…what are the options then for the diesels?