AC resurrection and questions

[WAID]

Yep, that is a quick disconnect. It was there for assembly in factory. They could have a vacuum pulled or freon in with it disconnected and then just hock it all up on the assembly line. That's why the hoses that hook to the pump had valves too. Later trucks they did away with this stuff. Those orings weren't in my reseal kit either. I ended up swapping on a newer style hose. Also the screen I think you are looking for is the orifice tube. If you separate the line going into the evaporator it is down in the evaporator inlet tube. If you are doing a 134a conversion now is the time to install a 134a orifice tube while you have it apart.

Sent from my SAMSUNG-SM-G890A using Tapatalk

Do you have any details on the newer style hose you installed? I have the new orifice tube ready to put in with the new drier once I get what I can figured out on the system. There was a little bit of debris on the old orifice tube but the hoses on the compressor all looked clean inside.

Update this morning the system held some vacuum, but has dropped down from -30 in Hg to -11ish in Hg. So there is some leak, but won't be easy to find I fear. Ordered a new compressor and figure I will proceed with that route and will charge the system with some dye and check it with a sniffer.

 

[laserjock]

Dye is really the best bet for finding the leaks. It’s hard to find a vacuum leak and it may only leak in one direction (vacuum or pressure) depending on seal integrity.

 

[tjsea]

Do you have any details on the newer style hose you installed? I have the new orifice tube ready to put in with the new drier once I get what I can figured out on the system. There was a little bit of debris on the old orifice tube but the hoses on the compressor all looked clean inside.

Update this morning the system held some vacuum, but has dropped down from -30 in Hg to -11ish in Hg. So there is some leak, but won't be easy to find I fear. Ordered a new compressor and figure I will proceed with that route and will charge the system with some dye and check it with a sniffer.

The hose I used was off an early 90s truck I believe. I got it at the junkyard and had both of the ends that my truck needed. Ford used a couple different end styles (quick connect or threaded fitting) so just find the one that works for your truck.

Sent from my SAMSUNG-SM-G890A using Tapatalk

 

[raydav]

I had a compressor shaft leak and UV die and soap suds were no help. I found the leak by submerging it in a tub of water and pressurizing it. It actually took a while for bubbles to start. Longer than soap suds lasted.

If you have an R12 system it is not necessary to change to R134. I have been using Envirosafe for a couple decades. It is compatible with R12.

And my current test gas is propane. It is cheap and is an excellent refrigerant. And yes I know it burns. So what. If it leaks it just flashes off.

 

[renjaminfrankln]

I am in a similar situation. It was 100 degrees yesterday and AC has now moved to the top of the list over fixing my fuel tank senders and replacing cab mounts. 89' and have no idea how long the factory AC has been out. The clutch is blown on the compressor and the belt was removed a long time ago. Has been converted to 134a at some point (sticker says so). I was curious to see if it held any pressure so I depressed one of the schrader type valves and a little hiss came out but not much. So at least it has not been completely open to the elements.

for about $215 I ordered a new compressor, drier, red orifice tube and o-ring kit. I guess the plan is to slap all that on and then vacuum the system down, charge it up and see what happens.

Questions:

Is this a good starting point? I have not worked on a/c systems beyond swapping out some bad o-rings to fix a leak.

The new compressor indicates it is loaded with PAG oil. Do I need to add oil to the system or just vac it down then charge it up with 134?

If everything looks fine (no black nasty stuff or metal in lines) should I bother flushing the evaporator and condenser?

 

[chillman88]

@renjaminfrankln

PAG oil is not compatible with the old R12 oil. You will need to at minimum flush the system and replace the dryer (which you already said you bought). I certainly wouldn't trust that it was all flushed out properly during the original conversion, not given the price of a new compressor.

After that you will have to add oil still. My 91 called for 10oz total, should be the same for an 89. Only problem is knowing how much is in the compressor.

 

[typ4]

WAID, im in newberg if you need help. You will have to come to me. Or meet at my sons house in Milwaukee.

 

[franklin2]

That is a quick disconnect that Ford used, it can be taken out if you have the right fittings but they usually don't leck. I replaced my compressor and receiver/drier and the blue orvice tube. Two years ago and I got a kit with a life time warranty. And I still use R12 it is still the best on these old A/C trucks. If you change out theR12 with 134 you will have to change the oil out and fulsh the system to get the old oil out.

You can leave the old oil in place if you use ester oil.

 

[franklin2]

I would fill it with this instead of regular R-134. Its a hydrocarbon blend so the molecules are larger and more similar to r-12. That means it will not leak through the old r-12 hoses like 134 will.
Also it performs more similar to r-12. Conversions without a parallel flow condenser to dissipate the heat often don't do very well.

Older hoses exposed for years to the r-12 and the r-12 oil are "pickled" over time and will not leak the r134a. New hoses in the store should be r134a compatible. I only see a problem if you bought some NOS hoses off ebay that were never used in a system, and were the old style hoses.

 

[david85]

I'm glad to see more guys switching to the hydrocarbon refrigerant.

Rebuilding the AC system can be done on the cheap if you find a "good used" compressor but the end result rarely works quite like new.

If buying a new compressor, don't get a rebuilt. Get a new one. And if you get a new one, replace the rest of the system.

The compressor is by far the single most expensive component in there. Basically, if you go new, go all in.

 

[chillman88]

You can leave the old oil in place if you use ester oil.

He said that the new compressor has PAG oil in it already is why I mentioned completely flushing it.

 

[WAID]

WAID, im in newberg if you need help. You will have to come to me. Or meet at my sons house in Milwaukee.

Thanks for the offer. I may take you up on that if I struggle too much more. The rain the last coupledays has kept me from doing anymore work on it unfortunately.

 

[WAID]

Well finally got a chance to work on it today. Ended up finding a leak on the pressure switch fitting on the old dryer so I ended up swapping that out(hardest part of the process) and charging the system. The cheap amazon sniffer I got didn't seem to show any leaks(except maybe on the low side conversion fitting, will have to watch that) System is blowing cold now with what I hope is enough dye to let me know if anything else is leaking. Fingers crossed.

 

[franklin2]

Sometimes soap on a suspect area will find a leak also. It may take awhile on a very slow leak, but suds it up, and come back 30 minutes later and you may have a spot of white foam there. Also any areas that look oily is a spot where it has been leaking for awhile.

 

[Oledirtypearl86]

Also checking ng for leaks you can buy A injection kit from Uview tat will inject 1 ounce of dye in to a already charged system I think the kit and dye is about 40 bucks