88-94 5.7 Suburban A/C Diagnosis and Tuning

[1998_K1500_Sub]

How many of the mounting bosses are being used on the bracket to support the compressor? It looks like three, two of which (if I'm seeing it properly) are the ones "egged-out".

I always wanted to put a V5 compressor on my V6 1995 Blazer, but never did. I no longer have that truck.

 

[Wildblue19]

3 of the bosses are used to bolt up, 2 oblong with the lowest hole unmodified. It's on there pretty good. Contacting a few aftermarket air companies with my CAD models to see who's willing to make the lines.

 

[1998_K1500_Sub]

I just wonder if those bosses have the strength to hold onto a compressor for... many, many miles. IIRC, GM braced that bracket (and compressor) with two struts, one to the intake manifold and one to the water pump. Of course a V5 compressor won't tug on the bracket like a cycling-clutch compressor, but when bouncing down the road...

 

[L31MaxExpress]

I just wonder if those bosses have the strength to hold onto a compressor for... many, many miles. IIRC, GM braced that bracket (and compressor) with two struts, one to the intake manifold and one to the water pump. Of course a V5 compressor won't tug on the bracket like a cycling-clutch compressor, but when bouncing down the road...

You could always grind through the rear mounting holes, use a longer bolt and catch all 4 mounting ears.

 

[Wildblue19]

I think it'll live as-is, I'll keep an eye on it. Not going to do any more bracing. Fatigue -might- be an issue but if I need a new compressor mount due to cracks they're pretty much available everywhere.

 

[Wildblue19]

You guys got me thinking and grinding out holes to make stuff fit just isn't really my style. I picked up a second 5.7 compressor mount and designed an adapter plate and spacer kit to mount it much more professionally. Got it all installed yesterday, super solid now.

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As for the lines, I ordered the fittings and hose I needed online. A few custom lines got bent and welded for me by the guys at Cold Hose. I needed to make a Y fitting to connect front and rear suction lines at the compressor, which can't be found anywhere.

I made what I needed by cutting up and combining 2 compressor adapters and alumawelding them together. Air tight and we'll see if it holds up over time.

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Charged up the system with 40oz 152a and looking forward to a warm day to see how it does.

 

[L31MaxExpress]

You guys got me thinking and grinding out holes to make stuff fit just isn't really my style. I picked up a second 5.7 compressor mount and designed an adapter plate and spacer kit to mount it much more professionally. Got it all installed yesterday, super solid now.

You must be registered for see images attach

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As for the lines, I ordered the fittings and hose I needed online. A few custom lines got bent and welded for me by the guys at Cold Hose. I needed to make a Y fitting to connect front and rear suction lines at the compressor, which can't be found anywhere.

I made what I needed by cutting up and combining 2 compressor adapters and alumawelding them together. Air tight and we'll see if it holds up over time.

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Charged up the system with 40oz 152a and looking forward to a warm day to see how it does.

Nice proper fabrication. If it for some reason does not hold up, they have T's that can be crimped into the hose itself. That is how the conversion company added rear air to my 83 G20 years ago. They used the AC hose clamps. Later when I swapped from the A6 to the DA6 style compressor I used a crimp in T.

 

[Wildblue19]

The soldered aluminum joint has a few pinhole leaks that weep oil very slowly. Small enough of a leak that my sniffer will not pick up the gas loss but the UV light shows the problem spots growing over time. I bought some "red epoxy" as a heat-cured aluminum / HVAC specific refrigerant sealant to hopefully stop that leak, will report back on how it goes.

Otherwise, at full charge and 75* ambient the V7 is able to cycle at idle, with the lowest pressure control valve installed. You can actually start to hear it destroke as it is pulling the low side near 25PSI.

 

[L31MaxExpress]

The soldered aluminum joint has a few pinhole leaks that weep oil very slowly. Small enough of a leak that my sniffer will not pick up the gas loss but the UV light shows the problem spots growing over time. I bought some "red epoxy" as a heat-cured aluminum / HVAC specific refrigerant sealant to hopefully stop that leak, will report back on how it goes.

Otherwise, at full charge and 75* ambient the V7 is able to cycle at idle, with the lowest pressure control valve installed. You can actually start to hear it destroke as it is pulling the low side near 25PSI.

I take it that it is cooling well even though it is not very warm outside?

 

[1998_K1500_Sub]

You guys got me thinking and grinding out holes to make stuff fit just isn't really my style. I picked up a second 5.7 compressor mount and designed an adapter plate and spacer kit to mount it much more professionally. Got it all installed yesterday, super solid now.

Those slider-thingies (see arrows in the marked-up picture) are used by GM to keep the bolts, when tightened, from compressing front bracket's bosses toward the rear bracket's bosses; they help form a rigid coupling between the front bosses, the bolts and the compressor, and a sliding coupling between the rear bosses and the bolts. In that way the compressor is still held firmly, but the bracket isn't subject to undue stress by bolt tension.

I've noticed two things in the picture:

- The slider-thingie isn't present on the middle rear boss. Was there once one there?

- I can't tell if the additional mounting gear you've made (which looks great BTW) maintains the function of the slider-thingies, i.e., to prevent the bolts from compressing the front and back bosses (i.e., as I tried to describe above)

Those things noted, I admire your handiwork

Edit: If anyone knows the proper term for the "slider-thingies", please advise. They may have some other function(s) than the one I've tried to describe above.

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