AC Conversion Question

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Jan 10, 2003 | 09:33 AM

flynhi

Thread Starter

Le Mans Master

Joined: Aug 2000

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From: Austin TX

AC Conversion Question

I'm converting my AC to a R-134 using the OE condenser and evaporator coils as well as a Sanden type compressor. The evap coil must have the upper refrigerant pipe modified to connect straight forward (vs. OE curved and down). Since my engine is installed and I have headers, removing the evap coil is not an option.
So, the question is - how do I modify the upper connecting pipe? Cut with a hack saw and let the AC shop figure it out? Cut with a plumbers copper tube cutter and flare the end? Wait and drive it to the AC shop and let them torch it off and weld/solder a threaded connection?
Your input please.

[Modified by flynhi, 5:46 PM 1/10/2003]

Jan 10, 2003 | 10:23 AM

74-Roadster

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Joined: Nov 2000

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From: Fort Worth TX

St. Jude Donor '06

Father & Son St. Jude Donor '09

Re: AC Conversion Question (flynhi)

Quote:

The evap coil msut have the upper refrigerant pipe modified to connect straight forward (VS curved and down).

I'm getting ready to do an AC rebuild as well. CAn you tell me "why" the you must change the connection direction?

Also, I've read that when you use 134, the expansion valve should be recalibrated to make the system as efficient as it can be and hence get the outlet temps as low as possible. Have you heard or looked into the expansion valve? From what I can tell it's part of the evaporator in our cars.

Jan 10, 2003 | 06:00 PM

Wrencher

Safety Car

Joined: Oct 1999

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From: NorCal

Re: AC Conversion Question (flynhi)

When I had my original A/C manifold re-hosed with barrier hose for 134a, Hal's Auto Air in Sacramento cut off the original ends and TIG welded on the new barbed ends suitable for the r134a hose. I don't see why a competent shop couldn't do the same for your evap, even if it's on the car. Just clear out around it. otherwise, weld up an adaptor. Be kinda bubba, but it should work.

Hans

Jan 10, 2003 | 06:06 PM

Larry B.

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From: Orlando Floriduh

Re: AC Conversion Question (flynhi)

I am running R134a in my 69 with all of the stock original parts. I just changed to the ester oil. You just cannot overcharge the system with R134a. It takes about 60% of the R12 charge. Mine works great even in Florida's hot humid summers.

Jan 10, 2003 | 06:13 PM

Wrencher

Safety Car

Joined: Oct 1999

Posts: 4,101

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From: NorCal

Re: AC Conversion Question (74-Roadster)

It's the STV that needs to be adjusted, not the expansion valve. I took a chance and left my STV alone replaced the expansion valve and it works killer. I also re-sealed the compressor, new dryer, replaced the o-rings and added the right oil.

Hans

Jan 10, 2003 | 06:50 PM

flynhi

Thread Starter

Le Mans Master

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From: Austin TX

Re: AC Conversion Question (Wrencher)

Wrencher,
Thanks for your response. Can you see any reason why I can't cut it now to get the turn down out of the way as long as I tape off the end to keep crud out?

Jan 11, 2003 | 05:32 AM

mrvette

Team Owner

Joined: Jul 1999

Posts: 65,492

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From: Orange Park Florida

Re: AC Conversion Question (flynhi)

flynhi, leave that pipe alone, as the evap itself if really really really weak inside there and will NOT stand much if any flex with you working on that pipe....cutting it will allmost certainly break the evap coils....the ends where that pipe goes in is weak corrugated aluminum....

GENE