Options to connect new AC Compressor

[Ekliptix]

During my big block swap (350 to 402), I bought a new AC compressor but found the connections are not compatible. I took it to a mechanic who said it'd be at least $500 to get it hooked up. I'm looking for a solution to get AC hooked up and working again in my truck, preferably using the new compressor.

The old working compressor when the small block was in:


The new compressor I bought: https://www.summitracing.com/int/par...0602/overview/

Admittedly, I bought this compressor because it fit with the big block accessory brackets I bought, not thinking it'd be tough to connect it with the AC hoses after. That was a bit of ignorance on my part.

In the truck now, with the apparently incompatible connectors.




Appreciate any input on options to get the AC hooked up again. The old compressor does not appear that it will fit on the new big block accessory bracket, in fact it's so heavy a second support is required at the back of the old compressor which used to attach to a bolt on the 350 intake manifold.

[davischevy]

I went to the parts store, found the fittings, rented the parts store crimper, cut the hoses and installed and crimped the fittings.

[Ekliptix]

Alright, that's encouraging. As an AC idiot, which parts of the AC hose assembly do I need to keep? Specifically, can I do without the chamber that the red fill port is attached to in my photo above? If yes, my plan will be to:
1) get a few crimp style fittings to attach to the compressor, like these, one with a red fill port.
https://nostalgicac.com/media/catalo...1/c132-3_2.jpg
2) Rent a crimper tool.
3) Cut the AC lines, removing the chamber with the red fill port from the system.
4) Crimp the hoses into the new fittings. Secure fittings to compressor.
5) Bring to an AC shop for them to add/cycle refrigerant. I don't know how that all works.

Thanks for the input.

[Stocker]

As one AC idiot to another would it make more sense to exchange the compressor for one with the correct fittings? The old R12 systems used a particular style of fittings -- R134a systems use different fittings that are not compatible with R12 components. My concern would be that you need all fittings to be of the same type, or you might end up with a system that is fully connected, but the AC tech is unable to hook up his machine. Just a thought....

[B. W.]

Davischevy & Stocker both have good points. Another thing to consider is the POA valve, if you're switching to 134 you will want to get that re-calibrated (search on this forum)
A shop should be able to build both hoses you need for about $100-150. They can build them with the high & low side service ports. Add another $100-150 to pull a vacuum on the system & re-charge.

So, in short, I'd get the POA valve re-calibrated, then take it to a shop & have them build hoses & charge the system.

[Ekliptix]

I didn't mention it, but the truck's already been converted to R-134a, I bought it that way with the black compressor shown. If I understand, the POA valve is the component near the blue fill port in my photo above, and needs to be calibrated when refilling/pressurising the system by an AC professional, is that right?

I'm pretty sure the current hoses just need these type of fittings to connect to the new compressor. Or are the old and new compressors so different the new one, Sanden 508 style, will not work with my R-134a system?

[RichardJ]

>>Sanden 508 style, will not work with my R-134a system?<<

The retrofit on your old system would have included changing/flushing out the old Mineral Oil. It should have been replaced with new Ester Oil.

The Summit listing says that 508 is supplied with PAG oil.

You MUST do a very, very thorough flush of the complete system to get rid of all traces of any old oil.

[Bigdav160]

Back in the day of R134a retrofits, GM didn't recognize the need for flushing. Mineral oil and PAG do not co-mingle. In the presence of R134a just settles to the bottom of the system. GM doesn't recommend ester oil either. I do know many people use it as it is cheaper than PAG.

To the OP, your compressor is fine with R134a. If those fittings fit the compressor and the hoses, then they will work fine. As mentioned, the POA should be recalibrated. That is not a job just any A/C tech can do. F.A.Benny, on this board, can do it for you.

[davischevy]

I have two POA's at F.A.A.Benny's now.

[RichardJ]

>>GM doesn't recommend ester oil either. I do know many people use it as it is cheaper than PAG.<<

I know one of those statements is not true, so I'll just ignore the other. $8 for 8 oz on both.

[B. W.]

Originally Posted by Ekliptix

I didn't mention it, but the truck's already been converted to R-134a, I bought it that way with the black compressor shown. If I understand, the POA valve is the component near the blue fill port in my photo above, and needs to be calibrated when refilling/pressurising the system by an AC professional, is that right?

I'm pretty sure the current hoses just need these type of fittings to connect to the new compressor. Or are the old and new compressors so different the new one, Sanden 508 style, will not work with my R-134a system?

You are correct, that's the POA valve. It needs calibrating before the system is charged. F.A.A.Benny on this forum can do it (I have not used him but many here have)

The fittings in your picture will work, they have the correct R134a service ports

the Sanden 508 compressor is designed for R134a (Sanden has discontinued making R12 compressors)

[Andy4639]

You have several routes you can take.

Order the fittings on line and crimper and do it yourself.

Classic air group can help you if you go this route.

Local AC shop person should have everything you need also.

A good parts house old school like NAPA have the crimping tool and all the hose and connections they can do the job also.
The muffler can be done away with on the new system and you will never notice it being gone.
Take the two hoses loose on the other end of the compressor mount and have new hoses ran.

[MARKDTN]

I didn't see where the OP said he was converting to R134. I wouldn't. I would just use R12. Then you don't have to recalibrate the POA. And it will be colder.....

[CaptRMW]

Post #6 says 134. My 134 system with a Sanden 508 compressor connected to an ARA under dash slimline unit was cranking out 36 degree air on my way to breakfast this morning. I have a full 30 pound tank of R-12 but won't be using it.