Chevelle Tech - View Single Post - r134a numbers with stock Condenser & replacement POA
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post #30 of (permalink) Old Aug 21st, 19, 2:56 PM Thread Starter
Tech Team
Join Date: Jan 2011
Location: Los Angeles
Posts: 309
Re: r134a numbers with stock Condenser & replacement POA

Originally Posted by hjdca View Post
Hi Al, I saw one of posts from Aug. 3rd on oil capacity. If I understand your post correctly, this is what I should be looking at for proper oil in the newly rebuilt system.

New March P412 Compressor (Sanden 7176) - already comes pre-filled with 100 cc of pag oil. I cannot find the exact type of pag oil yet.

So, if I flush all the lines, then I should add an additional amount of pag oil (exact type TBC) for each additional component based your post from Aug. 3rd..

Parallel flow Condenser - 1 oz
Evaporator - 3 oz
Dryer - 1 oz
New r134a POA valve - 0 oz ??
New Expansion valve - 0 oz ??

I plan to just pour this oil into each component, button up the system, then move the clutch on the compressor clockwise twenty turns or so before I vacuum and charge. Do I have this right ? Do I need more oil for the new POA valve or expansion valve ? Thanks !
ok, so, I talked to Mike over at Original Air (Tampa, FL), the numbers we are looking at for oil are too much for my aftermarket March P412, (Sanden) compressor. What Mike told me is that for a complete system with a similar Sanden compressor they put in a max of 210 cc oil. He said I could put that in, but, no more.

The numbers we are looking at above are used when replacing just one part in the system, ie. if you replace the condenser, then, it is taking 1 oz. of compressor pump oil with it. If you replace the Evaporator, then, it is taking 3 oz. of compressor pump oil with it. The concept is that you have to replace that oil in those components to keep the right amount of oil in the system.

My understanding now is that if you start with a new system, with all new components, then, all you need is a full compressor of oil and no more oil in the other components. As the system gets used, the compressor oil gets distributed in the various components, so, if you replace one, you have to estimate the amount of oil you lose, so, it can be replaced. That is what the chart is showing you in the Chevelle manual.

So, for example, if you system needs 11 oz., that is 11 oz just for the compressor. You put 11 oz into the compressor, button up the system, vacuum and charge. Your compressor is not specified as only needing 6 oz and the other parts needing 5 oz. In fact, the documentation is telling us that this oil that the compressor needs is then distributed during usage and must be replaced when a new part is introduced.

The March MCH-P412 says it comes with 100 cc of Sanden SP-15 Pag oil. So, now I have to decide if I add another 100 cc of SP-15 to the whole system or not add any at all except the 100 cc that is already in the compressor.

Do I have this right ?

1970 Chevelle SS396 (408), Fathom Blue,
Original Block & Forged Crank, KB Pistons, Edelbrock 6045 Heads,Comp Cam 292H, March Serpentine, RPM AirGap,750HP,100hp Nitrous
A/F Wideband,Tremec TKO 600, 12 bolt,
30 spline Moser Axles, Richmond 3:73's, Hotchkis control arms, swaybars, springs, Wilwood 12" rotors D/S, 4 piston calipers

Last edited by hjdca; Aug 21st, 19 at 3:18 PM.
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