Oh, I have a '73 and '76 Ford manuals, it was in the early AM, my mind was just going over it instead of resting. Getting back up and writing let me "download" the thoughts, so I went right to sleep afterwards. I have the York on the truck, and a Tecumseh in the basement. I forgot about it not having a pressure switch, but I know what you're talking about. After coffee, this afternoon, I'll look in the book and check the procedure and I think the service valves have it isolated now, good time to check oil. I know the bearing is smooth as silk, and I can easily spin the inner part of the clutch on the shaft. It may well be that I can still pull the isolated compressor and do the seal kit and get some correct mineral oil in it if needed. I'll have to refresh my mind, might be Ester is OK as it is a crossover oil. Wish I had a wheelbarrow full of those once cheap R12 cans.



Thank You!

 

Several years back I bought a #30 of the R12 off of craigs list. I was and am licensed for it. I paid $300 for it. I only have 1 vehicle now that takes it, so it was a lifetime purchase. AFAIK you don't need license for the small cans. You can try checking estate sales. Everyone had a few cans squirreled away. If you buy make sure to check the weight. A friend had some old cans and some of them leaked out after 30 years.

 

Since my last post a while ago, I did some chores, then pulled the truck around, put the belt back on, hooked the wire up (clutch) and tried it out. Compressor runs fine, not so noisy, and the air from the vents is tolerable. As I had said, I wired in a toggle with light to cycle the compressor like with defrost, etc. If I put the AC mode in "vent", the AC is not normally cycling the compressor, but I can flip the switch and do so. In that mode, it both has the outside air duct open in passenger kick panel, but the door doesn't totally shut off the passenger kick vent. That way, if driving down the road, fresh air coming in the driver's side kick vent can do the same for a passenger. If I flip that compressor switch, the air coming through the fan is "AC-ed" as it goes through the evap core if there is a charge. Well, today it was not much different with the switch flipped on, but I did see 78-79 temp air coming out of the dash vent in the center while it was 82-83 with switch off, no other changes, fan on high.

Based on that, I'm left to believe I have "A" charge, though it be a really low charge. I'm thinking the R134 conversion is in order. along with new seals, rcvr, exp valve, etc. It's at the point, it ain't gonna cost me but some time now. Worst can happen is I have a good venting system.

So, "Yeah, full circle" back to start. Was three routes open ... remove, go R12, convert to R134. I got "conflicted".

Until I do more, I unplugged the wire and took the belt back off. At least I know nothing catastrophic is wrong with the system.

Capacities & quantities notes:
Ford in both my '73 and '76 manuals says 2 pound or 32 ozs. R-12 refrigerant
Ford in both my '73 and '76 manuals says 10 ozs system oil. (mineral oil for sure)
42 ounces total charge is 42 ounces or 2-5/8 pounds, or 2.625 pounds.
Most sources say 70-80% R12 to calculate R134. Some go as high as 85%.
2 poundsis is 32 ounces. I know to be guided by gauges, but these give me estimates.

• 32 x 0.70 = 22.4
• 32 x 0.80 = 25.6
• 32 x 0.85 = 27.2

I've seen nothing about the system needing less oil, just a different oil. I'll use Ester oil.
My same Ford manuals describe oil check, adjusting level, dip sticks, sealing, etc of both York and Tecumseh compressors.

 

We used the 80%. Your sight glass will not function correctly with 134, shows bubbles even though full.

 

Steps to do "checklist".

1. Evacuate system of whatever is in it.
2. Isolate the compressor via service valves.
3. Disconnect at compressor. and remove compressor to replace shaft seal on bench, draining compressor first. Using the ester oil as lube for seal kit, and then fill compressor with the 10 fluid ounces (ester oil) as specified by Ford. I have scoured the manuals, they address the seal, but everything is geared to servicing a compressor removed after isolating it via service valves from the rest of the system. Ford instruction seams geared to a mechanic dealing with a system that is still charged with R-12 & oil, etc. I will be changing oil in the compressor and will have nothing in the system. My question then is, would I ... or should I ... put the whole 10 fluid ounces in the compressor sump now as I reinstall it ... but before opening the service valves connecting it to the empty system?
4. While system is still empty and there is no pressure ... Flush evaporator core, hoses, & condenser as I replace my receiver and expansion valve and all O-rings lubed with the same ester oil.
5. Install the R-134a adapter fittings on high and low side R12 fittings.
6. Open the service valves at the compressor now.
7. Wear eye protection.
8. Connect gauges with gauge valves shut ... Blue to low or suction side (upper fitting) ... Red to high or discharge side (lower fitting)
9. Pull a vacuum below 25 inches for 30 minutes minimum with yellow to vacuum, open both sides of gauges..
10. Check for it holding a vacuum.
11. After vacuum complete, close both sides, connect first can of R134a to yellow, but both sides still shut at gauges.
12. Start truck, windows down, AC on high, fan on high, temp **** on lowest end. RPM about 1500.
13. The compressor is the only "moving" part needing lube oil, and it'll have a full dose ... if I do it this way.
14. Watching both gauges, open blue line gauge valve slowly, watching pressures with eyes on both sides compared to charts based on the then ambient temperature.
15. Keep high side under safe top limit from chart.
16. Expect to use maybe 24 - 27 ounces (by weight) R-134a.

From calculations in above post #18:
32 x 0.70 = 22.4 ...... 32 x 0.80 = 25.6 ..... 32 x 0.85 = 27.2

Reference "My Question" ... #3 ... Should I do it this way, putting oil charge in at once. I know that some sources say use R-134a with oil in it, but then you'll not know how much oil you have ... but you could charge it like that, then isolate the compressor and check the oil level in the compressor with the dipstick Ford describes, the book says most of any oil will be returned to the compressor with use? My stash of R-134a is not anything but R-134a, it has no oil in it.
Did I miss anything, or screw up in my steps to take?
I know, it maybe seams that I'm a PITA obsessed with this ... but I also know some out there have done this a hundred times

 

Have you considered using one of the R12 drop in replacements such as Arctic Air or Envirosafe?

 

I must admit, not in depth, but I will do so this evening as I'm "open minded" on it still. Thanks for the feedback.

 

To my understanding these are hydrocarbon based refrigerants. So they will probably be flammable but so is the new yf1234 they’re using in brand new vehicles. And so is the propane that farmers everywhere are putting in cab tractors.

Myself, I’d run the stuff and not think twice but definitely do your own research to decide what you’re comfortable with.

 

It's not like there's gallons of it either. I keep running into mentions of RS24 (R426A):too, been reading the Q&A page in the "data files" drop down, interesting read. It ain't cheap, nor do I see it offered in consumer size "cans".
RSL - the refrigerant specalists (refsols.com)

Update 07-24-2023:
So today I picked some ACPro AC flush and another bottle of Ester oil, so I'll have plenty on hand. My new Ford 7 blade fan arrived, and so I now have what all I need just sticking with "the R134a plan". Today, had a couple cars to get inspected, so we did that.. Maybe tomorrow? First thing I'll do is check/add charge to the Mercury.

 

Well ... FUDGE!

Today, with temps expected to be in high 90s and all, I got an early start. Plan was to get the compressor off and into the basement, and swap my new fan on, before it gets hot. I got all bolts holding the compressor out except one, the underneath front bolt closest to the water pump. I found I never put the other one in on that end. I found that the system was empty, no pressure. Finally, after trying every 9/16I had, I give up getting the compressor off and in the basement today.

Then I decided to at least get my new fan swapped on. I found my fan shroud was broke right under the top hose where it's narrowest. I got so focused on getting those 4 long bolts in and threaded, I totally overlooked that I should have taken the opportunity when the fan bolts were out to remove the pulley and then I could have easily removed three bolts in a bracket that acts as a steady from AC mount to PS mount. I had to wrestle getting those 4 bolts into the fan too.

Next time, when it's getting cooler maybe, I'll try again, but removed the fan and shroud and pulley and get that bracket loose so I can get to that one hidden bolt. I just got frustrated, and it didn't occur to me for some reason. I did get a call from an investment advisor ... maybe that was what sidetracked me?

I still think it would be a good idea to reseal the compressor shaft, but I also found that the short fat hose from high side to rad core support connection is actually not a tight fit on the fitting where it connects to the service valve on the fitting it's crimped to, it twisted too easy..... might be my leak? In the Summer of 1977 a friend and I spent a whole hot day detailing his blue '68 Shelby GT 500KR to drive it up to Gettysburg for a weekend Shelby Owner's Club meat, we had it looking better than new, it blew that very same high side hose off it's fitting. My friend took it as a "sign", so we drove my Mustang instead. Mine ain't blowed off, I just noticed it would twist. Maybe NAPA can replace and crimp the hose using my ends?

Woooops ..... my goof.

Here after 3pm, same day, I took a flashlight and looked. I had been reaching across under the compressor, trying wrenches there ... but I looked with good light just now, and shazam, there it is, plain as day.

I'll get it off after-while ... when it cools down outside, make it easier to drain, etc.



I can get it from this angle, socket, maybe crows foot, wobble extension, ratchet.

 

All of the above, kept many a Snap on dealer in business for years.

 

And I went out to the carport, it's shaded ... but there's no breeze in there... Used a 8 or 9 inch long 9/16" combination wrench as I still couldn't get a socket on it. Used the boxed end to break it loose, then knowing about where it was, was able to take the bolt out until it fell, about 1-1/2 flat each time flipping the wrench each time, placing the open end strictly by feel, it fell loose after about 10 hot minutes. Wrench was one of my Father in Law's, I know it's late '60s era chrome "Snap-On". He did add his initials to it.

It's off now, in the basement, on my bench. I'll clean it up, pour out the mineral oil that's in it, change the shaft seal, refill it with 10 oz. ester oil and then "get on with it".
I did double wrap the open hose ends under the hood, and zip ties seal spiders and other things out. An old "Flexicuff" holds it all near the master cylinder.
When I put it back, I'll save mounting the pulley with bearing until after I have the bolts in. If that don't work, it might not get used. There are 5 others.

 

All my late 60s/early 70s Fords when I was a kid had the Yorx compressors. Man, those bolts were painful. I usually left the compressor on the bracket, and pulled the whole bracket/compressor assy off together, but it was heavy and a pain.
I'm fine that my dent doesn't have AC, as I can choose when to drive it... But anyway, no vintage "snap-on", but here's what I use for those pesky buried 9/16" head bolts. the socket cup is quite short (about 1"), but it's useful to get more clearance. and while I never use it to break stuff from torque, it's a very compact ratchet!



I like your A/C procedure---might consider getting an 'oil injector'. I've used that many times--put in the amount you want to the graduated cup, then open the valve on the injector to the low side while under vacuum.
I also have a small kitchen digital scale that reads in oz, so i can weigh the R-134a cans before, and then during the fill to know how much I've put in.

 

Well, took the clutch and magnetic coil off, shaft looks good. That pulley with the flywheel alone weighs might near what the compressor weighs. In operation, the pulley and flywheel spin with the engine, so when the clutch kicks in, it really is hardly noticed with that flywheel. It was very obvious that the shaft seal had been leaking oil for a long time, and it didn't want to clean off so easy. I used a DeWalt screw gun with a 1/2 socket to back the bolt out, it did about three hits and zipped it out. Then a 5/8-11 bolt inserted and tightened down to contact acts as a puller, then I energized the clutch with a battery pack long enough to tap a wrench on the bolt CW, it was a light tap, but enough that the clutch popped loose. Just the weight of that pulley was enough resistance. Without the pulley in place, the compressor bolts to mount will be easy enough to start - tighten. I'll clean on it more, see if I can get it looking better and swap the seal, drain it & fill to correct with the Ester oil. I did clean, wire brush, some sanding, the clutch/pulley assembly and paint it.

This compressor is from a '79 F-150 CC ... but I still have the '73 F-150 compressor and clutch assembly with the same pulley, etc, but it is on a set of 360 mounts. Just for kicks, I picked it up and it spins easy too. I think it's a Tecumseh?

 

I had an idea I might get this done today, and trial run it tomorrow?

I had noticed a small black curved piece in the clear plastic sealing wrap of my new Compressor seal kit. Today, I removed the 6 little 1/4" hex headed bolts around the plate over the seal and was all ready to swap it for the new seal. I carefully cut the plastic ... then I found the enclosed new carbon ring was busted and the piece I saw was the part broken out. Not an expensive kit, but just a "well s**t" moment.

In a few weeks, it'll be sneaking up on Fall. Coupled with the hose I think is not so tightly gripped in the swaged-on clamp at the fitting. I'm at a point that I'm not in a rush. I am not sure about the hose, but I will have to wait on a new seal kit I've just ordered. I have all the bolts, shaft key, etc cleaned in a container boxed up with the compressor ... so I'll likely pull the hoses, exp valve and condenser with receiver since it all has to come out anyway (to replace o-rings, receiver, exp valve), clean the evaporator and condenser out, and just have my stuff ready for when I get the compressor done and further investigate the hoses ... or maybe I'll get some new barrier hoses.

Not much need to get it done before Spring ... and even then, I'm really just doing it to say "it works", might use it a time or two per summer. Could just box and/or store the compressor, hoses, condenser, new seal kit, new receiver, new exp. valve and I would still have a super nice functioning vent. I'd block off the evaporator's ends easy enough (some clear plastic and zip ties) and just leave it in place. I'd be about as happy as it's not like I'll likely drive it on a road trip to Vermont or Alabama. If I did take a trip & desired or needed to drive a truck, I'd take the red one anyway. I have a dozen plus cans of R134a, and three other cars and a truck that use it, so I'll still use a couple to charge this when it gets to that point. Doesn't make much sense to charge it this August just to maybe loose the charge by next Summer.

08-06-2023 update reference a new seal:

Today, I went ahead and very very carefully opened up the new seal kit #24019 using a razor blade This one had an extra piece of cardboard in the packet that was vacuum sealed, it appears it was to protect that carbon ring. Used two small screw drivers to wedge to get that stamped dust shield off, it didn't take much, besides there's a new one in the kit.

In examining the pieces, looks like the real seal that get's rubbed against anything is that carbon ring spinning against the back of the plate (held on by 6 small 1/4" hex head bolts). The plate has a square cut O-ring on it's back side, but once in position it doesn't move. There is a spring behind the carbon seal to press it against the plate surface. The rubbing side of the carbon ring has a "step" in it's surface. My OEM one has the same step, maybe slightly worn ... but the back of the plate also had slight wear. behind the spring is a rubber seal with retainer, my original one stayed in the compressor on the shaft until I used a pick tool to pull it out. Once in place, that rubber doesn't slide against anything ... and it seems to just seal between the carbon ring and crankshaft behind that spring.

Small wonder these things last so well.

Whatever, do not misplace the funny looking shaft key that gets used when the pulley goes on.