SD7 adapter not sealing

[derekf]

I've got an SD7 compressor and the Holley 199-202 adapter, and it's not sealing.




I tried adding o-rings without success - it was "better" (read: held some of the pressure for a few minutes) but not sufficient.



I see when I'm zoomed into the first pic that the aluminum isn't smooth - have I ruined the adapter?

[Vimes]

That does look pretty rough, and it doesn't take much for R134a to escape. A new adapter is 20 bucks, just replace it.

You're probably also going to want the washer as well as the O-ring. You could try just doing the washer but as expensive as R134a's getting to be, it would be cheaper to replace the adapter and try the washer too.

[KUL FIR CHICK N]

That block has some pretty ugly machining and it looks like additional damage as well. Not sure where they source it. We (VA) make our blocks in-house. The o-rings are also unique to the SD7b10 compressor and it doesn't use sealing washers. Depending on how long it's been open and how much oil it lost, you may need a new drier and to add oil, but be very careful adding oil. If it was just a leak, don't add more than an ounce or two.

Here are the o-rings and replacement block:

https://vintageair.com/sd-7b10-10-re...essor-o-rings/
https://vintageair.com/7b10-compressor-block-kit/

Ryan

[derekf]

Perfect, thank you; new block ordered.

[Vimes]

Vintage Air would definitely know better than a shadetree like myself would on whether the washer is needed.

[derekf]

Local Summit had the Holley one in stock, and could get me the VA one by middle of next week.

I bought both. I'll try the new Holley tomorrow. Something will be getting returned.

How long is too long for the system to be open for the drier?

[KUL FIR CHICK N]

Vintage Air would definitely know better than a shadetree like myself would on whether the washer is needed.

Those are "dual slim line" seals (DSL). We used DSL and SSL on the '16-22 Ford GT system and we use "single slim line" (SSL) on our Gen 5 TXV, but the SD7b10 compressor uses its own kind of oddball design "o-ring face seal" (ORFS) o-rings. They seal well and are reliable, but they tend to fall out and get lost when you open the system.

OK, that's enough nerding-out on AC seals for one night....LOL.

[KUL FIR CHICK N]

Local Summit had the Holley one in stock, and could get me the VA one by middle of next week.

I bought both. I'll try the new Holley tomorrow. Something will be getting returned.

How long is too long for the system to be open for the drier?

The drier has a pack of desiccant in it that is needed to ensure long life of the system. On a new install, I try to leave uncapping the drier for the very last step before connecting the lines and getting the system on a vacuum. When servicing the system, I cap both sides of whatever I open immediately and then get the system on a vacuum as soon as it's closed back up. We're talking minutes here, not hours. In my opinion, five minutes is too long. If it's been open for more than 30 minutes, I'd strongly recommend replacing it. Moisture in the system silently destroys things, much like what happens when you have a poorly maintained engine coolant system. Everything seems fine until all of the sudden you start springing leaks. You open it up to discover internal corrosion that eats the system from the inside out.

[derekf]

the SD7b10 compressor uses its own kind of oddball design "o-ring face seal" (ORFS) o-rings. They seal well and are reliable, but they tend to fall out and get lost when you open the system.

In accordance with the prophecy, the replacement Holley part also doesn't seal.

Should I have o-rings on the outside of these two ports? I do not.

[dhutton]

You need the o rings. Metal to metal won’t seal. The ones he listed above
https://vintageair.com/sd-7b10-10-re...essor-o-rings/

[derekf]

Surprisingly enough, with the correct o-rings, the compressor sealed.

I was still leaking though.

Used the port for the trinary switch to pressurize the system and sprayed everything with soapy water. Found the leak:



The fitting itself.

And then I saw this:



Sigh. Disconnect and seal the drier (not buying ANOTHER one) and off to Summit again, new fittings.

With new fittings it does hold vacuum.

First can of freon, everything seems to be working. It was ~105 today, so per the chart I found:



I was shooting for 55 low side, 330 high side. I couldn't get above about 40 low, 300 high and the little vent thermometer says I never improved past about 90 degrees. More investigation required.

[dhutton]

One can of Freon is nowhere near enough. Keep adding.