Converting to R134a and Sanden compressor

I just completed the same conversion. I don't think it's wise to run R134 through an R12 system due to contamination, but you can flush out the condenser. The evaporator? I did not pull the dash for that. Everything else I changed.

Don't forget the expansion valve under the dash. Be careful, if you twist it off you'll have to pull the dash out. You need two large wrenches and patience.

I got it from Nostalgic AC parts. SKU 14-9875. $20.00.

Also, be aware of your connections. The original system uses flare fittings, not the best for R134 as it may leak out faster. You might want to convert to O ring fittings.

The Expansion valve I listed is for flare fitting, but they have O ring too, plus any adapters you might need.

There are a lot of Sanden knockoffs. I spent hours searching for authenticity through the heaps of probable Chinese junk. I finally decided on Summit number RSS-58033 (SD508). Who knows.

Finally, I believe the bracket is Pantera specific.

That's all I have.

The generic bracket found from many sources will be just fine for a Pantera.

The generic copies of the genuine Sanden compressor are reported to be of low-quality and are to be avoided.

Larry

Ivan,

IPSCO makes a replacement idler pulley assembly, that makes tightening the A/C compressor belt much easier.

http://www.ipsco.org/Pantera%2...s/Idler%20Pulley.htm

They sell the adapter bracket too.

I have done a few A/C systems now.

OEM hoses are okay or a kit with newer barrier style hoses can be had from the vendors for peace of mind for $425. I made up quite a few for Larry Stock at Pantera Parts Connection with an option that offers additional length so you can route the hoses in the rear fender well along the chassis rail, thus tidying up the engine bay if you so desire.

In my experience key success factors that many miss are;

1. a full reverse flush of the system prior to dismantle so you get through the evaporator core (pressurized flush bottles are available)
2. using ester oil in the system (compatible with any residual mineral oil).
3. changing out the expansion valve as R134a has a different pressure drop and orifice size requirement

Julian

Thank you for all the suggestions. Are you sure that expansion valves for R134a had a different size orifice? The description of expansion valves state compatible with R12 and R134a therefore now I am a bit confused. I was planning to replace the expansion valve anyway.
https://nostalgicac.com/flare-expansion-valve.html

The IPSCO idler pulley looks like the way to go.

I can make the new hoses to have flared ends for the condenser and evaporator, or I can have them made with the newer O ring type fittings and then use adapters. The adapter adds another place for a possible leak but if I ever wanted to upgrade the evaporator or condenser there would not be a need to replace the hoses, just eliminate the adapter. Any opinions on which way to go?

I am still debating what to do about the compressor. The Sanden 508-type compressor offered by Summit is made by Vintage Air, are these made in the USA or China?

Compressors seem to come with PAG oil. If I am replacing all the hoses and flushing the condenser and evaporator should I still dump the PAG and go with Ester oil instead? Seems to me that I should be able to use PAG as there should be very little to no residual oil.

Ivan

Two Sanden applications I've worked on didn't need the idler. I just removed it. The slotted holes in the Ford bracket allowed enough adjustment of the Sanden adapter to get adequate belt tension. The 180 degree belt wrap is not prone to slippage, unless it's crazy loose. You do have to install the compressor and belt simultaneously.

quote:

Are you sure that expansion valves for R134a had a different size orifice? The description of expansion valves state compatible with R12 and R134a therefore now I am a bit confused. I was planning to replace the expansion valve anyway.
https://nostalgicac.com/flare-expansion-valve.html

What they should more correctly say is the R134a valve will work in a R12 application, as R12 specific valves are now hard to find.

quote:

I can make the new hoses to have flared ends for the condenser and evaporator, or I can have them made with the newer O ring type fittings and then use adapters. The adapter adds another place for a possible leak but if I ever wanted to upgrade the evaporator or condenser there would not be a need to replace the hoses, just eliminate the adapter. Any opinions on which way to go?

If you want to upgrade the condenser and evaporator why not do it now and ensure it all fits correctly?

quote:

I am still debating what to do about the compressor. The Sanden 508-type compressor offered by Summit is made by Vintage Air, are these made in the USA or China?

Looking at Vintage Air website it would appear their Sanden compressors are true Sanden, beware anything that says "Sanden style"

quote:

Compressors seem to come with PAG oil. If I am replacing all the hoses and flushing the condenser and evaporator should I still dump the PAG and go with Ester oil instead? Seems to me that I should be able to use PAG as there should be very little to no residual oil.

I have worked on more systems where the issue has been the incompatibility of the two oils gelling than anything else, but if you want to ask for advice and then second guess it with confidence you can get all the mineral oil out then go for it!

quote:

Originally posted by nor'easter:
Two Sanden applications I've worked on didn't need the idler. I just removed it. The slotted holes in the Ford bracket allowed enough adjustment of the Sanden adapter to get adequate belt tension. The 180 degree belt wrap is not prone to slippage, unless it's crazy loose. You do have to install the compressor and belt simultaneously.

Good to know, I'll wait to buy the idler. Do you have a NAPA or Gates number for the AC belt? There is currently no belt on the compressor.

Ivan

quote:

If you want to upgrade the condenser and evaporator why not do it now and ensure it all fits correctly?

I do not want to upgrade the condenser and evaporator but might have to if the cooling is not adequate.

quote:

Looking at Vintage Air website it would appear their Sanden compressors are true Sanden, beware anything that says "Sanden style"

Got it. I will go with Vintage Air

quote:

I have worked on more systems where the issue has been the incompatibility of the two oils gelling than anything else, but if you want to ask for advice and then second guess it with confidence you can get all the mineral oil out then go for it!

I'll go with Ester oil. How much oil does the system take?

Thanks for your advice.
Ivan

Note the 'bracket' some are speaking of can be either the huge steel plate bracket bolted to the front of the block & heads and mounts the alt and the AC compressor, OR a small u-shaped adapter-bracket that is used to run a Sankyo-Sanden AC compressor in a Pantera. The big bracket is Pantera-specific (two versions) while the small adapter-bracket is generic and was once included with Sankyo/Sanden compressors sourced from dealers. Making one from 1/4" plate is a 10-minute fabrication.

On your OEM York compressor, there are freon shut-off valves on top of the assembly. If someone has shut them off, you will have no A/C no matter what you do to the poor thing. The York is very heavy, shakes the car at idle and is an early '50s design, but they can be made to work.

As for swapping to r-134A freon, the OEM evaporator valve under the dash has a relief spring inside that controls the system pressure. The settings (or springs) are different for the two freons. Second, in the OEM setup, there is a fine conical screen in one leg of the same valve, designed to catch trash and ground-up dryer material from the can in the trunk. The tiny screen is usually plugged solid so no freon (either type) will flow. Hook it out and clean it, then return it and replace the drier. With r-134a, the screen is usually left out for more flow of the inherently poorer heat-transfer of r-134a freon.