A/C Manifold Gauge Readings

[uscmas412]

Next I pulled an initial vacuum to 29 and let it sit for 10 minutes to check for leaks. Good to go. Pulled vacuum for an hour, then recharged.

I ended up using all three cans of r134. When you purge or open the lines, some is lost.

I did check at 24oz and the pressures were low, so added third can.

This is at idle in a shaded garage, overall pressure seems low for the ambient temp. I did give her some throttle, but pics are at idle.

If you take the DS headlight out, may be a good time to add something abrasive resistant to the ac line going towards the switch in front of battery. I noticed there was protection that had decayed.

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[uscmas412]

First day of driving results, it's better but not perfect. Morning commute was standard, 40 ish at the dash.

The largest improvement was in the evening, I'm getting 42-46 at the vent within a 15 minute drive. For reference, internal temps were 120 at startup. I lowered windows to get out the hot air and left the a/c on external vs recirculate for a couple minutes.

I definitely noticed a drop in dash temperature when driving between 2-3k RPM. However, when I park at idle it will hold 44 dash. I definitely get lower vent temps with the fan speed on low, but that position really does not move enough air. When fan is on high, temps increase 2-3 degrees.

FWIW, radiator temps are slower to increase with this condenser. When I first started this experiment, highest I ever saw on the OBD gauge was 194 degrees. I added foam around the old Denso condenser and was quickly hitting 197 in stop and go traffic. I DID NOT add foam to the Nissen condenser install, and I'm back at 194 top temp. It just seems to take longer to reach 194.

I think my next move is to pull the fan clutch and replace with 15k oil along with swapping in an OEM A/C belt. I'm getting shards of rubber thrown in the engine bay, but cannot tell which set of belts. The A/C belt was originally loose (55 ft/lbs), but I tightened it to FSM spec on the high end (90 ft/lbs). Alternator belt tested within limits, however the belts are definitely not sitting above the pulley grooves per FSM.

 

[flintknapper]

It all looks pretty good to me. There are some final gains to be had by doing the fan clutch 'mod' and adding an Aux fan.