I just received new a/c compressor, accumulator/dryer and oriface.
AC shop took refrigerant out of system. Before i start to take things apart, can someone tell me where this oriface is? Can't see it's place on engine compartment, and shop manual don't say a word. Also, how much oil should we put to compressor and accumulator?
Refrigerant will be r134a.

Is there other tricks i should know when putting new stuff in?

Car is -87.

 

I have an '87 as well.

The orifice tube is put into one of the hard lines on the evaporator. Your evaporator has 2 lines, the lower on that turns 90* just before going into the evap is the one that contains the orifice tube. Disconnect that line and you will see the top of the orifice tube in there.

SunCR can tell you what to use for Ester oil amounts. I just put in a new evaporator and accumulator. I put 4oz in the accumulator and 3oz in the evaporator. I forget how much goes into the compressor.

Make sure you use the green o-rings, and coat them in ester oil before you put them in. There is an part # at autozone that has every o-ring you'd need for an '87 system. Let me see if I can find it, someone posted it here a few weeks ago.

 

Here some pic for a procedure that I'm writting (and have almost completed)... It is written for my 93, so don't get confused by the notes on the O-rings...

This is my old and new orifice tube. I place this picture out of order to show you what they look like before you remove yours.
Notice the O-ring is more to one side than the other. The bottom of the orifice tube is near the O-ring (left side).
Remember: The Orifice Tube is extremely cheap to purchase. Always replace your tube. Mine cost $3.25
As always, match them up. My new one is on the top. The old one is on the bottom.



Again, note how deep the orifice sets into the tube.
Also remember which way the flat angle is facing (some pipes have dimples and the orifice tube must be reinstall the same way).



Using a small pair of needle nose pliers. Slowly pull out the orifice tube.
Notice the O-ring is facing down.

DO NOT REINSTALL THE NEW ORIFICE YET… WE WILL INSTALL IT LATER.



This is the kit you need to get. It’s a SANTECH MT-2541, which fits all 1977 thru 1996 Corvette's.
I bought mine thru a local AirCon dealer, but found out later that this is a regular stocked item at Autozone. UPC is 7-80250-02364-5.
Since this is a universal kit for all Corvettes (and other GM cars), you will not use all the rings, you will have extras.
Again, make sure you don't buy the generic O-ring kit that Autozone sells, on my 93 none of them matched up.

 

If he is converting over to R134, and replacing everything, why would he use Ester oil? Bad move... He needs PAG oil, make sure you don't use the conversion kit oils, it's PAG100... You need PAG46....

I know I'm driving other forum members crazy with this long post but here is how you find your information.... PLEASE REMEMBER, this is for a procedure that I wrote for my 93, you need to check your FSM for the oil quanity/viscosity for your 1987....

Here is some basic fact...

Basic Fact for your 1993 Corvette, LT1, Auto, C68:
Compressor = Nippondenso 10PA20C
http://www.techchoiceparts.com

Oil used when converting to R134a = PAG46
http://www.efproducts.com/datasheets..._Oil_Specs.pdf
Location/Quantity of oil used: (Factory service manual 1B22)
PAG Oil – sold in a 8 oz bottle
Compressor – 1.5 oz
Evaporator – 3 oz
Condenser – 1 oz
Accumulator – 3.5 oz

Don’t use the conversion kits, most contain PAG-100 oil… You need PAG-46 for your Corvette!
This site found at: http://www.4s.com/fourseasons/tech_t...nfusion_02.pdf

Torques: (some are inch-pounds, some are foot-pounds)
A/C Pressure sensor – 44 inch lbs
Pressure Cycling Switch – 18 inch lbs
Accumulator Hose Fitting (both sides & evaporator) – 30 foot lbs
Compressor Hose Bolt (on Compressor) – 30 foot lbs
Condenser Hose fitting (both) – 17 foot lbs
Evaporator Tube Condenser fitting (bottom) – 12 foot lbs

When converting to R134a, you must only charge your system to 85% of the normal R12 charge. R12 = 2 ¼ lbs (36 oz) x .85 = 30.6 oz

 

Thanks for great responses. I will take it apart tomorrow. Let's see what happens.

 

I see all this great info on repairing and updating the AC system but not mention of system evacuation again to remove air and moisture. Is evacuation required for long term care free use of the AC?

 

Vacuuming is the most important thing in the whole process. Much like when you have a blood test, the tube are in a vacuum. The vacuum makes your blood easially go into the tube. Same thing is true with the AC lines. You want to make a vacuum, and also remove the moisture from the lines. Your Accumulator has a item in it to attract moisture call desiccant. Here is a small write up on Accumulators.

Accumulator: On a 1993, the A/C system will have an accumulator. The accumulator “Can” contains desiccant, which is a chemical that attracts moisture. You will usually find desiccant with items such as new electronics. They desiccant packages usually have “Do Not Eat” on them. (As if you thought they would give you food when you bought something like a stereo system).
The desiccant serves a vital function, since the combination of water and refrigerant forms corrosive acids. Acids not only reduce A/C performance; they can ultimately destroy the system. The accumulator also serves as temporary holding tanks for liquid refrigerant.
You may have heard people call the Accumulator a “Receiver Dryer”. Although these two parts serve similar purposes, the receiver dryer is always connected to the condenser outlet (high-pressure side) and is used exclusively in expansion valve systems. In contrast, the accumulator is attached to the evaporator outlet (low-pressure side), and is only found in orifice tube systems. The primary functional difference is that the accumulator is designed to prevent liquid refrigerant from being drawn into the compressor.
The Accumulator is a sealed unit. It is welded shut and you cannot see the insides. Well, I know your curiosity will get to you, so I decided to open one up so you can see what the insides look like. Here it is:

 

I'm pretty sure he needs PAG150... (according to the auto a/c forum). PAG46 is pretty old...

At least 150 is recommended for my R4. I assume Nippondenso's would be similar.