C3-1971-TWO Questions (A/C & Temp)

[Greg F.]

I have two questions:

1. I was driving my stock, 71 small block with the A/C on tonight. It's not a lot but I've noticed a little "splatter" on the underside of the hood above the A/C unit. Is this condensation or something else leaking?

2. For others that have a 71 small block....what is a normal water temperature range on the gauge when driving about 55-60 mph (A/C off). I live in Florida and the outside temp was about 90 degrees today.

Thanks,
Greg

[Jack H.]

Re: C3-1971-TWO Questions (A/C & Temp)

If the 'splatter' is directly above the front shaft of the A6 compressor, it's most likely refigerant oil that's getting by the compressor's front seal. About the only place you see water moisture 'leaking' is from the rubber bladder seal on the bottom of the Harrison air box bolted to the firewall OR condensation from the metal refigeration lines that traffic freon to/form the evaporator inside the air box.

My '71 SB holds a pretty constant engine coolant temperature in the 180-190F range while running at cruising speed on the freeway. The only time the temp gauge pegs higher is during LONG periods of idle (stop and go parade traffic) or under heavy stress (climbing a steep mountain with A/C running and high ambient temperatures)....

[Paul D.]

Re: C3-1971-TWO Questions (A/C & Temp)

That "splatter" may or may not be something to worry about. Those compressors used a felt like packing after the seal to absorb any oil that would expectedly get past the seal. It is probably saturated over time and unless you have access to a good and reasonably priced AC man, I would be hesitant to tear into a well operating AC system. I am not certain, but that packing may be accessible without discharging the system. If that's the case, then maybe go ahead.

In any case, I would look into installing one of the compressor guards listed by most Corvette parts suppliers. I think it's advertised in the "Driveline". Try to clean that spatter off ASAP and hope it hasn't gotten past your underhood paint. I understand that oil will ruin paintjobs, both current and future. Some say it's like brake fluid if it gets to the fiberglass ; almost impossible to get out.

[Greg F.]

Re: C3-1971-TWO Questions (A/C & Temp)

If the 'splatter' is directly above the front shaft of the A6 compressor, it's most likely refigerant oil that's getting by the compressor's front seal. About the only place you see water moisture 'leaking' is from the rubber bladder seal on the bottom of the Harrison air box bolted to the firewall OR condensation from the metal refigeration lines that traffic freon to/form the evaporator inside the air box.

My '71 SB holds a pretty constant engine coolant temperature in the 180-190F range while running at cruising speed on the freeway. The only time the temp gauge pegs higher is during LONG periods of idle (stop and go parade traffic) or under heavy stress (climbing a steep mountain with A/C running and high ambient temperatures)....

Thanks Jack. Mine runs about the same. It only goes up a bit when the AC is on.

[Greg F.]

Re: C3-1971-TWO Questions (A/C & Temp)

Thank you Paul. I plan to get that guard.

[Jack H.]

Re: C3-1971-TWO Questions (A/C & Temp)

You'll only find the absorbant cloth on Delco Remy supplied A6 compressors. The aftermarket folks who rebuild them, remove and discard the cloth telling buyers to 'expect' some minor refigerant oil leakage during the rebuilt compressor's initial wear in...

The get to the cloth, you need to R&R the clutch and pulley. This means you need the special tool to remove them and NO the job doesn't require dumping refrigerant. Also, when the clutch and pulley are re-installed, you need to set the correct air-gap (roughly 20 mils) on the clutch.

Expect a typical A6 compressor to 'throw' oil when it's fresh and the front bearing/seal is wearing in AND when she's old and there's appreciable bearing/seal wear. If the later is the issue STRONGLY consider replacing the front bearing/seal with the the later service replacement CERAMIC versions! They're virtually bullet proof...

[Jack H.]

Re: C3-1971-TWO Questions (A/C & Temp)

Makes sense.... When the A/C is running, heat pulled from the cabin is 'dumped' by the condensor that's mounted in front of the radiator causing ambient air temp through the rad to climb.

[William T.]

Re: C3-1971-TWO Questions (A/C & Temp)

If it is your AC compressor leaking you should definitely get it fixed. The oil will eventually saturate through you fiberglass and show up as small imperfections in your paint on the hood. When the sun hits them you will see the oil on the top side of the hood. It is next to impossible to get out. Some suggested leaving it in the sun after you strip the paint, baking it at a paint shop. I tried them all but eventually bought a new hood.

Good luck