PUT A/C oil high or low pressure side?
 

I just replaced my evaporator on a E320 Wagon 1995 and I am going to replace the compressor and dryer.

I researched the forum and manual and I need 120 ml of PAG oil of viscosity of 46!

Now the question is weather to put 60 ml into the high pressure side and 60 ml in the low pressure side or everything in one port and if does it matter which?

Thanks... Are there good instructions for a DIYer to charger the system. I have a pump and gauges. ... I would like to charge it with exactly the right amount but doing it with cans seems a hit and miss!

Thanks...

When I did this task on my 95 wagon, the A/C tech added the oil through the low side port. If you haven't changed the drier yet, it's a bunch easier if you remove the left side headlite assy.

With the system open and thoroughly flushed, distribute the oil with a little in each component such that it totals the proper volume. Put some in the evap, some in the condensor and some in the filter/drier. You can put just a little in the compressor.

After everything is all together before evacuation, turn the compressor 12 or 15 revolutions by hand to make sure it is not liquid locked.

How does liquid lock a compressor?

Tries to move through the outlet, but can't get there in time, causing damage to the hard parts.

I had a compressor apart and I don't see how that can happen. The reed valves should let any liquid just pass right out.

Fluids are not compressable, that is why your hydraulic brakes work.

I'm well aware of the almost incompressability of fluids. But the A/C compressor is not your brakes.

So...Chas,
 

Prove us all wrong ,fill your compressor with 2 Oz of Lubricant,
(Don't bother Vacuuming, the Compressor Will Blow),fill with refrigerant and
turn on the A/C.

Get back to us on your empirical results.

Why would I do that?
I already posted that 2oz of oil had been added to the low side by the A/C tech. Or can't you read?
BTW, the results are excellent.

It's not a smooth flow of fluid, or you would be correct. It is a very sharp impulse and the oil has too much inertia to just start moving so fast, if the chamber is full.

Aha! The oil has more inertia than gas. That makes sense.
It's nice to get a reasoned response to a question-Thanks.

Okay, just fill the compressor with liquid, don't turn it by hand to ensure that it is not liquid locked and crank it up. It's your compressor, so you have all the right in the world to destroy it if you like.

I would say that filling it with oil and not turning it by hand, you would have a chance of NOT liquid locking the compressor. I suggested, as you would find on any a/c web site, that you turn it by hand to ensure no liquid is present to destroy the compressor. I suggested this as a courtesy by sharing my personal experience with you in an effort to save you a compressor. That's what we do here on this site. We try to help each other.

For those who don't believe that we know what we are talking about, they can tell us that we are full of it and do what they like.

As to liquid lock being impossible because of a reed valve, how do you think that the compressor COMPRESSES? The reed valve closes on the compression stroke. With liquid in the cylinder something has got to give. Even if it's the reed valve that gives, you will still have to replace or repair the compressor. We are only trying to tell you how to prevent that.

Your explanation of a reed valve is completely wrong. A reed valve is a one way valve and offers no resistance to flow as the refrigerant is compressed. You don't know what you're talking about.

Okay, yes it's a one way valve. If it's direction is such that it does not seal on the compression stroke and rather RELEASES on the compression stroke, then tell me.... HOW does the compressor COMPRESS the refrigerant?

Please answer this question since I know nothing and you know everything, HMMMMM.....?