Adding oil to depleted A/C system

[B.G. Smith]

You will only be able to obtain vacuum reading that corresponds to atmospheric pressure where you are located.

 

[B.G. Smith]

The vacuum pressure or lack thereof is determined by the barometric pressure at the time and place where it is being evacuated. Around here (28' above sea level) you can get pretty close to 30". PS Sorry for double post.

 

[RVTRKN]

Actually, you should measure in microns, standard is 750 micron for large systems and 500 for small systems. However I’ve always been able to achieve that at any elevation, at sea level as well at 6K feet’. First thing you do, calibrate gauges for atmospheric pressure to 0psi then use them. Elevation as well as sea level will change with the atmospheric pressure as it will rise and fall naturally. The inHg is not an accurate measurement of true vacuum, only micron is. If you go off of inHg it will get you close, but your gauge won’t be precise vacuum.

 

[Tuesdak]

If it has schraders that is a common leak area.

Dorman is now selling metal caps for some vehicles that seal these leak points like residential AC systems have. About time. I don't even start an AC job without new schrader valves in hand. Then I replace them esp. the high side. High side gets the high heat and derbis from the compressor just waiting to make a slow leak.

And X2 on Ford's rust bucket accumulator. Others use aluminum to avoid this problem.

 

[JR]

Just realized I haven't updated. Generally no news is good news, not so much in this case

Local dealer botched the order for my transmission lines. When I ordered them (over the phone) the newbie wanna be MWilson parts fella asked for my VIN which I did not have but relayed that it is definitely on file as other parts guys have looked it up for me over the years. Keep in mind we bought the Merc at this dealership and have had it serviced and bought many parts through them over the last several years. I'm a stickler for OE parts - I have bought ALOT through Nassief Ford.

So new guy says no big deal.
You sure? I can call back.
Nope, were good.
So I'm thinking, how many variables can there be for a 4.6/6R Premier combo. (Premier denotes AWD).
We're good.
Nope.

This of course is late Friday afternoon, looking at probably tomorrow or Thursday for the VIN specific trans lines. Then I can get along with my dipstick free trans service and finally my A/C service

Except were in the middle of a big two to three day shutdown so it'll likely be the weekend before I get back at it.

A bit perplexing, but my A/C seems to be holding.
This after 10+ days. I'm guessing under pressure she's gonna leak a little faster

A friend sent me this just a few minutes ago.
Neither of them brave fellas is me, I'm running the stick. Did I mention how brave they are

Boom tip height was ~ 320ft parked next to the stack.

 

[jgillott]

That's a serious height right there. Your friends must really trust you.

 

[JR]

Yes sir, earning trust is a mandatory two way street in this line of work.

Headed out the door for round two. Makes for a long day.

 

[JR]

Finally got back on the horse this weekend in an attempt to get the Merc back on the road. Ended up replacing two sets of trans lines and a power steering line that was looking pretty sketchy where it bolted to the engine. Figured this was a good time for a trans service so dropped the pan and installed a new filter and commenced to filling. In OEMs infinite desire to make it as hard as possible to service your own vehicle they eliminated the transmission dipstick so I had to get a little creative. I modified my pressure brake bleeder with a ball valve and a piece of 1/2" tube, it worked pretty good.

Hardest part was getting the trans fluid temp right to get the correct amount in, the book says it has to be between 175-185*. I confiscated an old meat thermometer to stick down into the fill hole and used my IR gun on the pan, they were within a few degrees of each other so I'm pretty confident in the level.

Also ended up replacing Universal's in the rear driveshaft. Couple of seals were dry rotted and checking out. Replaced with OEM Motorcraft, sandblasted and painted the driveshaft and cleaned the slip joint and packed with fresh grease.

And FINALLY back to the a/c system. Charged it up, shot some dye in and let er run. She blows cold again front and rear, after a few minutes I started crawling around with the black light and sure as daylight the rear lines are leaking....joy. I was surprised to see the amount of dye everywhere given the system held vacuum this entire time, coming up on a month now. Regardless, they're going to need replaced.

I also noticed the coolant lines for the rear heat are missing some hose clamps. Rusted to the point one literally broke in half and checked out and another isn't far behind. So add replacing about a half dozen clamps to the never ending list....gotta love living in the rust belt.

 

[DavidC]

In my current condition I would have never made it past the Motive adapter for the 1st week . Nice idea.

 

[RVTRKN]

Thats why you never trust vacuum as the determining factor of proving for leaks. I learned early on in my HVAC career, its a NO NO. Glad you found the leaks.

 

[JR]

In my current condition I would have never made it past the Motive adapter for the 1st week . Nice idea.

I can't believe it's been a month since I started this, between wrestling camps and getting my oldest squared up for his college credit classes at Kent State this year, running him back and forth to a full time job and drivers ed classes there has been zero free time. And Somewhere in between I have to fit a job in

I did learn an invaluable lesson on the trans fill. Book procedure says to have it running up to temp, pull the fill plug out and there is a small dipstick under the plug for you to check the level. I had the plug out to top it off after initial fill (ended up taking 8+ qts), got the level where I was satisfied and shut the engine off. At this point all I had in the hole was the little dipstick which happens to be RIGHT NEXT to the pass side cat which was HOT, so I figured I'd give it a few minutes to cool off before putting the plug back in. In the house getting a drink and my boy comes running in the house saying there is oil dripping from the Mercury. Turns out once the vehicle is shut off oil drains back to the pan, and that sneaky little plug ends up being below the oil level line

 

[JR]

Thats why you never trust vacuum as the determining factor of proving for leaks. I learned early on in my HVAC career, its a NO NO. Glad you found the leaks.

I'm just surprised that in close to a month of sitting under vacuum it only dropped a few in. Given the amount of dye on the lines I would have expected it to leak down more than it did. Thanks for all your help and suggestions.