A/C re-installed - how much oil / R134a to add and should I change the compressor?

[DMC5180]

Interesting, sounds like Hervey used the same port adapter fitting for both hoses.

Most systems typically use a smaller diameter discharge HP hose. Typical system is D -8 (1/2?). S -10 (5/8?) which is consistent with the slightly different port diameters.

Any possibility increase the port diameter or have the QC head drilled and tapped to accommodate the brass relief valve. You can see the spot where it go in casting.

This issue didn?t come up with my installation, as I didn?t use the Hervey hoses.

Btw, Ethan mentioned needing to drill the head port slightly larger in has last post here.


What about trying the GV head. ( horizontal ports like the original with HPR) looks like it has two large ports.

https://coldhose.com/products/sanden...ompressor-head


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[82DMC12]

Interesting, sounds like Hervey used the same port adapter fitting for both hoses.

Most systems typically use a smaller diameter discharge HP hose. Typical system is D -8 (1/2?). S -10 (5/8?) which is consistent with the slightly different port diameters.

Any possibility increase the port diameter or have the QC head drilled and tapped to accommodate the brass relief valve. You can see the spot where it go in casting.

This issue didn?t come up with my installation, as I didn?t use the Hervey hoses.

Btw, Ethan mentioned needing to drill the head port slightly larger in has last post here.



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Hervey did a lot of questionable things. But anyway....

I only need the discharge side to be about 0.75mm larger ID and my hose would fit. I could probably wrap sandpaper on a dowel and enlarge it with enough finesse and polish it smooth with 300 and 600 grit. That might not be too bad a job to modify. I'd probably try that before tapping the QD head since I don't have a set of SAE taps.

All that said, I did talk to a Sanden distributor tech in Texas. He said honestly the industry has moved away from HPR valves because, duh, they vent freon to the atmosphere which apparently some people have a problem with. Instead they just rely on the high pressure switch and as a backup they might have a heat-sensitive "fuse" that will blow if the system gets too hot. He said if the HPR blows, there's a good chance the compressor is already damaged anyway. That was his take on it and he suggested just running with the high pressure switch and let it do the job.

Not quite sure which direction I'll go yet.

[DMC5180]

Check my previous Edited post. You were probably writing when I resubmitted it.


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[82DMC12]

Btw, Ethan mentioned needing to drill the head port slightly larger in has last post here.


What about trying the GV head. ( horizontal ports like the original with HPR) looks like it has two large ports.

https://coldhose.com/products/sanden...ompressor-head


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Ah yes I see Ethan did say that. Been a few days since I read it and now I found out for myself.

I looked at GV head but discounted it because the ports are not in the same locations on the head as the QC/QD. I don't know if that's actually a problem or not. When I asked Coldhose and acparts.com both said they couldn't find a QC with HPR offering. I didn't ask if they think GV will work.

I'll give it all another look tonight. Tiny problem but I'll figure it out!

[DMC5180]

Nothing a 41/64 drill bit won?t fix .640. The hose fitting is 15.9 mm = .625. (5/


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[82DMC12]

Nothing a 41/64 drill bit won?t fix .640. The hose fitting is 15.9 mm = .625. (5/


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Unfortunately, the hole doesn't go all the way through the head at the same diameter. It reduces quite small like to 1/8" at the bottom of the hole. I'm afraid a drill press would be required to avoid bottoming out the hole. Or, since the hose only goes into the hole like 1/8" deep, I could try to dremel the ID just enough to fit the hose inside. Hmm. Nothing is simple!

[DMC5180]

Is the bottom of the hole Flat? Usually it would just be tapered to the drill that made it. But I guess they could have use flat face end mill. You only need to deep enough for the fitting to sit against the head not through it.


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[82DMC12]

Is the bottom of the hole Flat? Usually it would just be tapered to the drill that made it. But I guess they could have use flat face end mill. You only need to deep enough for the fitting to sit against the head not through it.


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Here are a couple more pictures. I think it's flat at the bottom. I will have to look at my bits since I think 1/2" is the biggest I have and stepping up to a 5/8" would be too big a bite without a couple of step up bits in between. Wish I had one of those big letter bit sets!

PXL_20221107_125536677.jpg








New QD head







Existing QC head with new HPR
PXL_20221107_125533748.jpg

[DMC5180]

Unfortunately Letter drill sizes don?t go that large. Home use drill bit sets don?t usually go above 1/2 inch. You usually have to buy individual bits when larger than 1/2.


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