A/C ORIFICE LOCATION

[CaptTom]

Thanks fellas for all the info.

I converted to 134 awhile back(I mis-stated in my original post), but either I got a cheese rebuild or poor installation and premature failure...9 months. This thing actually went down about three months ago.

And no... I'm not going back or making a fuss...trust issues. I also think they left my original drier in there instead of using the supplied one....I thought so when I originally picked it up- it had the old frayed sticker on it, but like I said, I'm no expert and had no idea it was a mandatory replacement item.

I got the remaining parts off of the old compressor, will install to new, then hire a shop to do the moisture evac and recharge the system...possibly do another flush to make sure I'm not the complete idiot I know I am with this system. Like I said..... zero experience with A/C, although I do know how it turns hot to cold....but that's it.

Anybody can bolt stuff up, but I want an expert to clean and balance it properly. I figure for a Franklin or two I'll be good to go for winter...... !

 

[CaptTom]

Just a quick update for the newbs and to clear up some erroneous advice I received and read several times.

First the PAG oil. As the mechanic was putting the supplied PAG oil into the system, the compressor overflowed at about 2 ounces. Make sure your new pumps aren't pre-charged.... too much oil is bad. Depending on the make and model of the vehicle(and it's different between years of our trucks- not always exact same systems) you need to check and see the recommended PAG oil capacity. In the case of the 1990 F250 7.3l, it was 7 ounces. We drained the pump, and there was 12 ounces in it after we added the additional oil.... then we re-added from a new unopened bottle, 7oz per recommendation. And yes.... it was added to the compressor directly. We had to rotate the pump by hand to get it all into the compressor.

Second Freon. In this case, we were using 134a. The recommended quantity was 3.25lbs or 52ounces. The big individual bottles we can get here are 22oz, so we put in 2x22ounces plus added a "partial" short can of 12 ounces. Having said that, the last 8 ounces was a guesstimate, but either way, we did not use the full can, and I feel pretty good about being in area. Too much Freon can blow hoses off of the high side of the pump if in excess, so it isn't a matter of "If a little is good, a lot is better". (Several stories told by mechanic and his "customers" coming in with blown high side lines for putting in too much Freon)

Since we could not measure the high side pressure because the mechanic couldn't find his "Special" Ford adapter, we did it by feel.... this guy has been a mechanic longer than most of us alive, so I trust him with his "Good enough" expertise.

Third..... yes I replaced "ALL" of my lines in my conversion to the 134a lines, but still the new high side line with the high side gauge nipple was still that stinking Ford proprietary fitting.... ridiculous. First Snap-On or Mac truck I come across will have a customer for that special adaptor. I'm going to buy two, one for me and one as a gift for the old guy who probably had it sitting right where he left it last time....

Fourth, after applying a vacuum to the system and charging some Freon into the lines, the compressor clutch would not engage/cycle. This is due to too little Freon(pressure) in the system to operate the switch on the drier. In order to help things along, he pulled the plug off of the drier and jumped the plug to activate the compressor clutch. We only had to do this for a couple of seconds while pumping in the Freon. Once enough pressure was built up, the drier switch felt the pressure and took over on its own. We use a paperclip to jump the 2 wire plug....very technical procedure! Just don't let the paperclip touch the truck body.... if it isn't obvious as to why....well....

Now I know there are a lot of experts on this board, who may correct me on this posting, which I welcome any clarification, but the info I'm putting out there is from an 80 year old shop owner who has been doing nothing but mechanics since 14 working on some of his grand-dad's Model T's so I accept his sage advice. I did the internet thing almost all of Saturday trying to edjimacate myself, and there's a lot of ridiculous opinions out there.... including the dire warning of not to put oil in the compressor directly because it might hydrolock it..... not so..... it went into the compressor fine, and then into the system once energized without a hitch.

So there is my biased rookie opinion and assessment of how things went down yesterday. Thankfully, the old man was a teacher, and sympathetic to my cause. He allowed me to do all the work.... you know, like white washing fences.... except for a couple of.... "Here, do it this way's" I got to do a shop class and learn something...... I might try and tackle my daughters VW next.... !

 

[chris142]

Just a quick update for the newbs and to clear up some erroneous advice I received and read several times.

First the PAG oil. As the mechanic was putting the supplied PAG oil into the system, the compressor overflowed at about 2 ounces. Make sure your new pumps aren't pre-charged.... too much oil is bad. Depending on the make and model of the vehicle(and it's different between years of our trucks- not always exact same systems) you need to check and see the recommended PAG oil capacity. In the case of the 1990 F250 7.3l, it was 7 ounces. We drained the pump, and there was 12 ounces in it after we added the additional oil.... then we re-added from a new unopened bottle, 7oz per recommendation. And yes.... it was added to the compressor directly. We had to rotate the pump by hand to get it all into the compressor.

Second Freon. In this case, we were using 134a. The recommended quantity was 3.25lbs or 52ounces. The big individual bottles we can get here are 22oz, so we put in 2x22ounces plus added a "partial" short can of 12 ounces. Having said that, the last 8 ounces was a guesstimate, but either way, we did not use the full can, and I feel pretty good about being in area. Too much Freon can blow hoses off of the high side of the pump if in excess, so it isn't a matter of "If a little is good, a lot is better". (Several stories told by mechanic and his "customers" coming in with blown high side lines for putting in too much Freon)

Since we could not measure the high side pressure because the mechanic couldn't find his "Special" Ford adapter, we did it by feel.... this guy has been a mechanic longer than most of us alive, so I trust him with his "Good enough" expertise.

Third..... yes I replaced "ALL" of my lines in my conversion to the 134a lines, but still the new high side line with the high side gauge nipple was still that stinking Ford proprietary fitting.... ridiculous. First Snap-On or Mac truck I come across will have a customer for that special adaptor. I'm going to buy two, one for me and one as a gift for the old guy who probably had it sitting right where he left it last time....

Fourth, after applying a vacuum to the system and charging some Freon into the lines, the compressor clutch would not engage/cycle. This is due to too little Freon(pressure) in the system to operate the switch on the drier. In order to help things along, he pulled the plug off of the drier and jumped the plug to activate the compressor clutch. We only had to do this for a couple of seconds while pumping in the Freon. Once enough pressure was built up, the drier switch felt the pressure and took over on its own. We use a paperclip to jump the 2 wire plug....very technical procedure! Just don't let the paperclip touch the truck body.... if it isn't obvious as to why....well....

Now I know there are a lot of experts on this board, who may correct me on this posting, which I welcome any clarification, but the info I'm putting out there is from an 80 year old shop owner who has been doing nothing but mechanics since 14 working on some of his grand-dad's Model T's so I accept his sage advice. I did the internet thing almost all of Saturday trying to edjimacate myself, and there's a lot of ridiculous opinions out there.... including the dire warning of not to put oil in the compressor directly because it might hydrolock it..... not so..... it went into the compressor fine, and then into the system once energized without a hitch.

So there is my biased rookie opinion and assessment of how things went down yesterday. Thankfully, the old man was a teacher, and sympathetic to my cause. He allowed me to do all the work.... you know, like white washing fences.... except for a couple of.... "Here, do it this way's" I got to do a shop class and learn something...... I might try and tackle my daughters VW next.... !

There is a couple of things worth mentioning. Even us old guys need to learn new procedures. First. Refrigerant fitting are all the same size. Does not matter if its a Ford or a Honda. R12 fittings are a different size than R134a Fittings.

If the original capacity was 3.25 lbs of R12 the R134a Amount is 85% of 3.25. This equates to 2.76 lbs or 44oz. If you guys put 52oz of r134a in your truck its overcharged now. You would have known of the overcharge if you had a proper high side gauge.

The Proper oil amount for R134a is 3.5oz of oil per pound or R134a. That equals 9.6oz. Id put in 10.

 

[CaptTom]

Oil-Check!
Freon-Check!

R12 fitting- NO CHECK!

I had purchased a new box of fittings for the quick connects v threaded connectors.... none of them would thread on, neither would his fittings.....high side only. All of the adaptors had fine thread female, and the nipple on the system is course thread male. Went back to auto store and got the shoulder shrug as you're suggesting. If I can find my thread gauge, I'll stick it on there and compare the two threads and report back. But definitely two different thread sizes. Also, hose reads "FOR 134a" on both sides.

The oil evaluation concerns me only a little. Since I had aftermarket Freon, not the bulk stuff mechanics get, I think it comes with oil in it too, how much I do not know. Not sure if he was considering this when he did the oil math. Either way, I will question him on what we did.

Thanks for looking over our shoulder too.... I've been learning a lot about AC lately....Good call and much appreciated constructive critiquing!!!

 

[chris142]

Interesting.here a shop must use a charging station.the general public can buy the small cans @azone and screw up there charge...me being a shop must use my station which is much better anyway

 

[franklin2]

The 134a with oil in it usually says it in big letters on the side of the can, and the can is a little larger than a normal 12oz can. The ones I am familiar with that have the oil already in them come from the retro-fit kits and they usually have ester oil in them, not PAG.

I just went through the certification course for CFC's, and if you go by the book none of the oils should be mixed. But in real life, people do just put the ester/134a mix into a system that had r12 without cleaning it up, and they all seem to have success with this. From what I have heard, if you do use PAG like you did, you do need to manually clean out the old r12 oil before you use the PAG. But it doesn't seem to matter much with the ester.

 

[CaptTom]

This system was converted awhile ago, so there is no mix of oils....THERE IS NO R12 in this system to mix at this time.

I also flushed the system with AC flush until the flush turned clear again. Hoses, condenser etc. It took about three 24oz bottles with an air/flush injection wand used for cleaning engine blocks. Very kewl device BTW. Found it at Harbor Freight for around $25. Plug it into air, drop suction hose into bottle, stick wand tip into lines, with a recovery bottle at the end to catch the good and viola! It was pretty doggoned brown, with some sediment in it. Mostly a black dust, but some small metal particulate.

I read the can's last night, one of the 22oz cans had 4oz of oil in it, so I'm a bit over in the oil dept by appx an ounce then. Does this matter if I'm an ounce over? The small 12oz can had none, and of course, I can't find the other 22oz can, I think I left it in the shop.

As far as a charging station, the failed unit not only locked up, but the old 134a went somewhere else, there was none in the system, no whoosh into the recovery bottle.

So far, plenty of cold air, with a nice puddle of condensation under the truck in parking lots.

 

[chris142]

1oz over oil aint nuthin to worry about especially in your large system

 

[CaptTom]

I have to go find the other brand I had in a store to figure out if it too had oil in it. If it also had 4oz, then I'll be a total of 5oz over.

You think this would work, or do I need to start over again? Except now the drier and the rest of the system will have oil in it, so I guess just removing some from the compressor, measuring what I take out is the route to go then.

FRikkity-frakk, clakkity-klack!

Well.... all part of the learning curve I suppose.... and I don't mind embarrassing myself over this to make it clear for others in my similar predicaments. I do appreciate the critiquing....

 

[chris142]

Stop ocd over the oil.its fine

 

[franklin2]

The only thing too much oil will do is reduce the efficiency of the system. If it's cooling good, like was said don't worry about it.

 

[CaptTom]

Stop ocd over the oil.its fine

Check!




So it appears by commentary I've to death...... thanks again fellas!!

Cool travels to you all!!