Cold at idle, not when running at speed

[bohica2xo]

The original York compressor on that car held a lot of oil. Not much of it was in circulation.

Compressors like the 508 design depend on oil returning in the suction line. It is possible to damage one with a long slow charge cycle.

Where is the low side port located on this system?

I am thinking a flush to bare metal on the system is a good idea at this point. Yes, that means removing the TXV.

The OCR for that system is something you will need to extrapolate, because it is a more or less custom system at this point.

Once it is flushed clean, are still considering R12, or are you going to move to 134a?

[Cps38]

Low side port is schrader valve on head adjacent to line connections.

[Cps38]

Sticking with R12.

[bohica2xo]

Low side port is schrader valve on head adjacent to line connections.

I have seen that suction port kill a compressor or two. Charging in to a vacuum with no oil returning.

Most 32 to 34 ounce capacity systems have 7 to 8.5 ounces of oil in them.

Once you get things cleaned out and a new compressor mounted, send the first can in to the evacuated system as a liquid - through the HIGH side port with the engine off. The discharge valve will keep the refrigerant out of the compressor, and you get some refrigerant in to the system to start circulation before you start the compressor. Charging that way from a bulk cylinder I can usually get quite a bit of charge in that way before running the compressor.

[andrew vanis]

I’m starting to get the feeling the only way to correct this is to flush the system. Is it preferred to remove the expansion valve, disconnect the lines at the compressor and flush through the evaporator, condenser, filter/drier and not the compressor?

From my non-professional knowledge, the filer(receive)/dryer is not flushed and always replaced.

Also the flush/no flush decision may apply to the Condenser depending on the kind you have.

Since almost no-one self0fills R-12 anymore (what you got a stash in your garage from 30 years ago?) I wonder if the new parallel flow condensers would make a R-12 system EVEN better!?

[Cps38]

Please explain your comment on flush/no flush condenser considerations…

[andrew vanis]

Please explain your comment on flush/no flush condenser considerations…

From what I (non-expertly) know some condensers have fine openings and operate in a way that a flush doesn't follow a defined path resulting in an incomplete/ineffective flush. Parallel flow condensers I believe are like that since they send refrigerant from a side manifold across several channels at the same time.

Older condensers had one tube (or oval) that serpentined back/forth so the flush had only one path and would cover the entire run and all surfaces.

....If you do have a stash of R-12, I wouldn't be surprised based on what it sells for these days if you could take it to a AC shop and trade it for a complete conversion and and running condition in 134a (ok, maybe its not worth that much / or maybe you have a lot of it )

as a DIYer, how are you capturing the R-12 you'll take out for the flush?

[andrew vanis]

Please explain your comment on flush/no flush condenser considerations…

also, to clear up situation who you are asking that question to you can use the " button on the top right of a post to quote the person (or write in their username). There are umber of users on here so the general "your" is not clear.

Another option is to use the caret ^ to reference a post directly above (^ I think this of what you wrote...) - that fails when someone else gets in a post before yours shows up since it looks like you are referring to the new poster's writing.

[Cps38]

Still locating shop for recovery.

[bohica2xo]

Interesting. Even a beater, non running Pantera project is a $40k car now.

I don't think I would have risked a chinese knockoff compressor on a project like this.


Anyway, the individual components of that system - the evaporator, lines and condenser can be flushed. The receiver dryer can NOT be flushed, and in a case like this I would discard it and start over.

The heat exchangers on those cars were well built, and should be ok if there is no mechanical damage or deep corrosion.