Automotive Air Conditioning Information Forum

Installed 20yrs ago. Never charged. Never energized. Prepping for a charge.

1. hooked up both low and high side gauges and pulled a vacuum. Only the high side gauge dropped to 30hg and has held overnight. The low side never moved. Is that indicative of a problem? Yes I had the valve open. should both sides be drawing down?

2. Got me thinking maybe I installed this wrong way back when. So, in this pic, the tubes coming of compressor appear to be same size but the fittings are different size. The male and female fitting on the left is clearly larger than the one on the right. Which is suction and which is discharge?

Is larger one on left the Suction to evap and one on right is Discharge to condenser? Is that correct? That is how I have it routed. However when you look at the top of the unit the S and D are reversed....D is on left and S is on right.
https://www.flickr.com/photos/19642395@ ... ed-public/
https://www.flickr.com/photos/19642395@ ... ed-public/

I don't think you have gotten any responses due to the images nto showing much related to S/D. What 4-diget model Sanden are you using?

I'll take a crack at it. The S (suction) port on the compressor should be connected to the tube leading from the accumulator or evaporator. The D (discharge) port on the compressor should be connected to the tube leading to the condenser.

JohnHere wrote: ↑Tue Jun 18, 2024 7:21 pm I'll take a crack at it. The S (suction) port on the compressor should be connected to the tube leading from the accumulator or evaporator. The D (discharge) port on the compressor should be connected to the tube leading to the condenser.

Yep. But I read it as they are unsure which port is S or D on the compressor.

thx for the reply. There were two questions.
1. why is manifold gauge set only showing vacuum pull on Hi side and not Lo side
I think I solved that. I replaced both valve cores and immediately got vacuum on both sides. Lo -25Hg and Hi -30Hg

2. I was asking if anyone knew which port on this Sanden 706P was the suction and which is the discharge. There is an S and a D on top of the unit but the actual alum lines have a cover on them so you can't see where they are connected. I know where they are supposed to route. I was just trying to determine which is which to see if I routed it correctly 20yrs ago. Those pics I posted show the diameter of the lines at the fittings. I believe the larger diameter line is the Suction (Lo) which I have routed to evap and the smaller diameter is the Discharge (Hi) routed to condenser. Sound right?

As I mentioned, what 4-digit Sanden number is the compressor? I can look up the model.

The only numbers on this unit are 706P embossed into the body. One internet search with 706P yields the words "peanut style." There is no tag or label. I believe it also goes by the name 7B10. Does that sound familiar?

It does not. If it is OE Sanden, it will have a plate or sticker with the 4-digit number. Aftermarket might not have the plate or sticker. Either way, your supplier should be able to tell you. Other than that, better images of the compressor port locations will be needed to help determine the port locations.

According to one image off the web, the forward closest to the clutch pulley is the suction port. Knowing this, follow John's information about tracking the lines.

Thanks for your help.

Be aware there are knock-off sandens out there , so the markings , labels, and such may not match up to the OEM manuals that Tim has