Hello 🙂,
I am a retired diesel and hydro tech with 40yrs. experience in that field. In the dealership dealership days before doing it sole proprietor, all AC work has handed off to a dedicated AC guy. I never got a black belt in the discipline. When I was a sole proprietor, I got by with vacuuming to 30, let sit a few hours and check for needle drop, spray out flushes ect.
Well….,, Friend has an 01 7.3 Powerstroke Excursion that sat for 10yrs. Sweet Limited with rear AC. He is a retired pediatric surgeon from Johns Hopkins. They tore down the parking garage and built a new one and the Excursion would not fit sooo, it sat at his house for over 10 years. He retired and asked me to get her going again. Motor, tranny out, gone thru and updated including getting rid of ticking time bomb mechanical diode on the direct clutch drum they used on the 4R100 for the 01 year and converted it to a sprag. Too much refresh and update to the 7.3 to list.
I got to AC replacement of all and hit a snag!!
The high pressure line that feed both evaps was not available. Only was were Fseries snd Exs without rear AC so I got a one for a single evap. That gave me the new rubber hose that I was after. I cut it and ised a Dorman AC line splice union and that allowed me to tie into the long metal high pressure line. Thpught OK after vacuuming down to 30. Wrong! Saw dye after charging.
Tightened split, brought pressure back up. Needle pn gauge did not move for 2 days.
Neighbor walks over when I am indide my shop.
I walk out snd the guy has his hands on my manifold. Do not touch! Did you turn anything? No. Ok. I never look and went about doing something else.
Well.. pressures acted weird. Everything was weird.
Recovered refrigererent and opened orfice tube joint.
I had put a Four Seasons variable valve upto 105 degree 38902 in it. Back it had blown apart because he DID touch( see photo). Unscrewed low line at the drier and blew out the jammed in part and the valve pieces with shop air into a rag. Ok, nothing got past the 38902’s orings. Then I took the schrader valve out of the highside port. I blew in with shop air the other plastic end that had a srction of screen intact and nicely sealing against the inside of line. See attached photos if I can figure out how to post with this forum’s software.
Ok, think cool, all out but now I am loaded with moisture. Put a new 38902 in, and new orings on lines, snap back together, tightened line nut at drier.
I took my 20lb CO2 mig tank ( full of course) off the welding cart and said to self you are alwsys using flux core wire due to wind anyway, go swap it for nitrogen and do the sweep I used to hear bits and pieces about back in the day.
Soo, feel free to laugh at the yellow belt. Initially typed purple belt and within a second thought.., You are in the presence of black belts do you better change that to yellow belt.
New humble guy…
Sinsays, go easy on me, please🙂.
I came back after swapping out tanks.
I vacuumed to 30. Let sit for 2hours. No needle movement.
Closed valve on hose at pump.
I connected to nitrogen tank.
Regulator screw all out.
Opened tank’s valve.
Screwed regular screw in a bit on new nitrogen regulator.
I opened the high side service port and slowly charged to 10lb.
Low side equalized relatively quickly.
I let it sit for 20 minutes.
Started the pull down.
Some very tiny bubbles on sight glass. Figured maybe some oil on vapor hitching a ride out. Less than first pull down after return trip from gas shop.
First pull down with nitro to 30.
Closed it all down and let sit for 45 minutes.
Recharge to 10psi
Let sit for 45minutes.
Now just one tiny tiny bubble on glass.
Closed all valves.
Too late at night to do the third.
Innerweb research so far for a vacuum micron meter is depressing. Reviews seem dicey for a budget model until you get to a Fieldpiece @ $269 with prine shipping from Amazon but it can’t be had until August. Fieldpiece seems to have them price fixed st that price-point with all vendors ( exactly what Rolex watch company does to make sure all heads het cracked evenly) and sure they have shipping on top.
Would LOVE a badboy model of s good brand that
that will link to my Iphone and let me see water drops saying good bye to a glat line on a graph but I unrealistically wish, especially when talking $269 is kinda rough as it will not get used much.
#1 Have I been doing ok on this job so far??
# Is there panacea in regards to a meter?
#3 really not crazy about idea of not using one on this massive system with all of exposure time in massive humidity and using shop air to get those pieces out.
It is 10:00 PM. I am still in shop. I need to shower, eat, crash, get up early and go play doctor on a sick International 466 diesel.
I will check in with you experts tomorrow.
I thank all in advance.
Post script. I do not see button that allows for posting pictures.