Lichamp AC Oil Injector R134A, R1234YF Refrigerant A/C Dye Injector Kit with Adjustable Coupler and Oil Checkers

I used this for injecting oil into my AC system. It worked as expected, but follow the instructions! I was very confused on how to set it up until I looked back at the item description and the instructions. I may have also received one that was used once, but that really wasn't a problem due to the high quality item this is. After all, how many times is a weekend mechanic going to use this? I'm probably going to give it to a friend who works on cars more often than I do. Too bad we couldn't just "rent" this from Amazon and return it for a fee. It's still cheaper than paying a mechanic to do it!

Quality

Instructions are backwards, they have their clockwise and counter clockwise mixed up , but it did exactly what it was supposed to do

With careful use this oil injector worked well for adding 1oz of PAG oil to the AC system of a 1994 GMC Yukon. The instructions are inadequate so the below might be useful. The package contents were as advertised with no missing parts. The manufacturing finishes of the received unit are rather rough so recommend cleaning out any loose metal from the threaded areas and hand grips. The scale was measured and correct, and no leaks were found in the seals. Recommend not running the cylinder all the way down to the 2oz level. We set the vernier to 1.75oz, filled the cylinder to the beginning of the threads, and screwed on the top without difficulty. Eliminating air from the hose and adapter REQUIRES connecting the hose end to the adapter tightly (or there will be a leak there!), turning the valve to FULL OPEN, connecting the brass fitting to the adapter, hanging the system with the adapter on top, and twisting the oil injection knob until oil comes out of the brass fitting. When air has been injected turn the valve to FULL CLOSED and remove the brass fitting. If any of these steps are omitted the system will pressurize and no air will be ejected. To add oil connect the adapter the the system LOW SIDE port, make sure the connection is completely on, and start the engine and AC. MUCH better yet have someone else start the engine and AC as keeping the injector away from the belt prevents disaster. Check for a leak (bubbles) at the adapter to system port fitting - we found none. Now open the adapter valve to FULL OPEN quickly as we did find a small leak around the valve shaft when partially open. No other leaks were found. When connected and valve open twist the vernier enough to add the desired amount of oil then FULLY CLOSE the valve. Turn off the engine and AC system, disconnect the injector, and wipe off excess oil. Test the AC system for leaks at the low side port to make sure the schraeder valve closed fully and replace the dust cover. The injector can probably be left partially loaded in lieu of cleaning if left in air removal configuration and the adapter valve is left sightly open to prevent pressurization. It should be clearly marked with the PAG oil number to prevent adding the wrong viscosity of oil to a system. Cleaning this injector to switch oil types will be difficult. As there will always be some oil on this unit after filling it would be REALLY nice if it had been supplied in a plastic storage box.

Aluminum shavings are all over the tool out of the box. Whoever wrote directions does not know the difference between clockwise and counterclockwise. Directions included with the product are incorrect. What are the oil checkers, and how do you use them? No directions for using oil checkers. I had to disassemble and finish sloppy drilling and threading. I cleaned all the aluminum powder and shavings with acetone. It works to inject oil, but the workmanship, cleanup, and directions supplied with the tool were poor. I kept the product but spent considerable time getting it so I could use it. I hate to think of the damage that could have been done to my A/C if I had used the tool as received.