Automotive Air Conditioning Information Forum (Archives)

larry sti on Fri April 11, 2014 12:11 AM

Year: 84
Make: honda
Model: accord
Engine Size: 1800 es2
Refrigerant Type: r-12

Today I tried to use my newly acquired mastercool 90375 oil injector. I wanted to add 1oz of oil before I vacuumed and recharged the system.
I hooked the hoses up the way the directions tell you to. that's step 1.step 2 says to'' turn on the vacuum pump and open the high side valve on the manifold gauge set.''
Step 3 says''with low side valve and oil injector valve closed,unscrew the oil injector cap and add 1 to 2 ozs of oil.'' step 4 says''after 29 in. Hg. of vacuum has been reached,
open oil injector valve. Continune running vacuum pump. OIL will be drawn into the A/C system.'' This is not happening 4 for me. The oil just sits in the injector reservoir and does not get sucked in to the system.
I never could tell if the vacuum got down to 29 in. or not because my high side gauge gives no vacuum reading only pressure ,and the instructions never say to open the low side valve. What I did was run the vacuum pump for about 10 minutes.
Then I opened the Injector valve on the bottom of the oil injector for about 5 minutes The oil did not move. I thought I was following the'' service procedure ''paper that came with it to the letter. What am I missing? What did I do wrong? Does the
low side valve stay closed the whole time? They never say to open it. Thank you in advance for any help.
Larry

wptski on Fri April 11, 2014 9:16 AM

I've looked at those instructions before. I believe it a mistake, you have to open the low side manifold gauge valve to pull the oil into the system. I've seen mistakes in other MC products instructions and product flyers as well.

wptski on Thu April 24, 2014 2:38 PM

I purchased the version with the R134A fittings and used it today. Worked perfectly following the instructions with the low side manifold valve closed! One thing I tried was add a ball valve between it and the manifold so one could open the low side to read the vacuum better. The only issue I had was that I go to extreme and use a micron gauge with a core tool on the low side. A micron gauge doesn't like oil so I had to remove all the fitting, adapters, gauge, etc. and clean the excess oil out. I was thinking that this might happen and should have removed the micron gauge at least!

Edited: Thu April 24, 2014 at 2:39 PM by wptski