Buying new a/c compressor how do i get ALL of the pag oil out ?

[candymancan]

Every single replacement im finding for my 90's compressor online they all come with pag oil in them. I need mineral oil because im keeping the system r12.

I dont have alot of money, and i cant afford a new condensor/dryer/line/ and all that BS. and my compressor seized in 2019. Sweating in my 90 is starting to ruin my drivers seat lol. Im just going to take the risk and buy a new compressor, disconnect the old one, install the new one, maybe have a shop vacuum it properly and refill with r12 and cross my fingers and hope it works. I mean i might get a dryer since theyre only 19$ but other than that i cant afford anything else

So yea.. since they all come with pag oil ?? I know you can drain a compressor but will that really get ALL of it out ? I heard pag and r12 dont mix and can explosive ? so i wanna be sure its all out

[SJTD]

I don't think it's the R12, I think its the two oils don't mix. Maybe flush it with one of those flush kits, head and case, and put mineral oil back in. And make sure to get the oil in the head and body and turn it by had a lot to distribute it.

Does yours have the hose connections that have the valves? If so this is why they're there, to allow removal of the pump without loosing the charge. You front seat the valves, remove the pump, install the new, suck out the air in the pump and open the valves. If you don't have the vacuum pump you could install the low side valve and crack it to purge the pump before installing the high side valve. Either way you'll have to add some gas.

[candymancan]

I needed a new charge anyway. I was planning on just getting a new compressor draining the oil out. And hooking it back up to the system. And have a shop flush the condensor and evap and then evac the system. fill the compressor up with oil and refill with r12. And hope this works.

Or can i not fill the compressor up wuth oil once i evacuate it ? Not sure how that works.

But im having a hard time even finding a shop wanting to even do a flush and evac on a 32 year old Jeep.

Its like everyone is just a bunch of panzies how is it any diff then doing thst on a 15 year old car ?? Its iritating.


To answer your question. Valves ? You mean the pin needle like valve on the ends of the hoses ? Yes i have two of those. I connect the r12 can. Then i have to turn the valve on the hose itself to let the r12 in. So youre saying since i have that all i need to do is close both of them. Then disconnect the lines from the compressor ? Then drain and flush the new compressor. Fill it up with oil and turn the pump to get it all in there by hand. Then hook it up to the lines and reopen the lines ?

How would installing the low side and cracking it open purge the pump. If the high side on the pump is disconnected ? Wouldnt that still be an openeing for air ? Or do i gatta connect the high side quickly while the low side is purging the pump ?

You sure these valves arent just to open and close the external low and high ports for when you hook something up to it or do they actually close the hose off as well ? Because ehen i fill the system eith r12 i turn the top valve to open the port. And then close it and remive the r12 can. I didnt think these also block the hose off to remove it from the compressor ? Because once i close the valve and take the r12 can off. The system free flows.. Soo how do i close the hose with valve ?? What does front seat the valve mean ? Does that mean turn it all the way clockwise ? Which i assume pushes the valve all the way in to block the port in the hose itself ?


Here is what mine looks like

[candymancan]

I guess i answered ny own questions. Found this video. I get it now. So turn the valve clockwise all the way. Then disconnect the hoses. Remove the comoressor.. install new comoressor with mineral oil. Then put the hoses back on. Then hook a vacuun machine up to the low side ? And vacuum the compressor. Then once its vacuumed. I open the valves and renove the vacuum pump. How do i do it the other way if i have no vacuum machine ?

Then i grab a can of r12 and refill as needed. And that should be it. No need to expose the system to air and i shouldnt need a dryer or condensor or evaporator.

Then plug it in. Turn the air on and hope it works. And hope when the compressor seized it didnt break and send metal in the system lol.

Thank you i think i have it down now. I just ordered some mineral oil 32oz bottle and a 508 compressor. My last question though is how much oil does the 508 take ? And what about the oil thats still in the lines and evaporator and so forth ?

https://youtu.be/gFFLYmD_2d4

[sonoraed]

Generally on a Sanden 508, remove old compressor and drain the oil into a measuring cup, then drain oil from new compressor,put into new compressor same amount of oil drained from old compressor, don't use the old oil!
Good Luck

[candymancan]

Ya i nought a 508 on amazon and 32oz of mineral oil. I know i have a small leak in the system.. but its so small it took 4 years before it needed refilling.

Thank you i didnt think about draining the old compressor into a cup and putting that same amount into the new one. I might add a tad more though due to the leak i have on the hose.

How do i flush the new comoressor to get that pag46 oil out ? I was thinking of just pouring in mineral oil. Turning the compressor by hand a few times. Then draining. And repeating that a few times. After that i assume the pag oil should nostly all be gone.

[candymancan]

Meeting someone in 20 min to buy 3 cans of r12 for 90$.. ouch but at least i got them. Had this guys phone number for like 3 years now thankfully hes still around and sold them to me. 90 i guess is about how much theyd be on ebay.. the last 3 i bought 5 years ago were 25 a peice

I forgot to ask what size they were but oh well.. itll be hard to find someone else with them in the next week or so.

Edit. Damn checked ebay. Theyre like 40$ a can now.. geesh.. i feel like buying this dudes last 2 cans for 5 total now. Lol.. but 3 should be plenty for many years

[candymancan]

Anyone know of a good r12 can tap ? Thr ones im seeing seem sketchy from reviews.

[sonoraed]

be careful too much oil is just as bad as too little, settles in the bottom of condenser/drier/evaporator and refrigerant has to push thru the oil equals high pressures, really should replace drier its the filter for the system,don't worry about residual pag in new compressor just let it drain for an hour or so, if old oil is really dirty should flush, have seen guys use brake cleaner and air pressure for DYI's,why so bent on R12?

[sirrus]

Anyone know of a good r12 can tap ? Thr ones im seeing seem sketchy from reviews.

That worked fine for me. Keeps the open can sealed for almost a year by now, much to my surprise

[candymancan]

Where did you buy those ? What brand ect. The ones im finding on amazon have terrible written reviews.. yet have 5 stars all chinese paid reviews it seems. Deff dont want to puncture a can and lose all of it.


Do you guys think i should have the system evacuated ? I found a shop who has the r12 gear and said a full evac and refill using my cans would be 100$. Or should i just soend about 20$ for the hoses and can tap and refill myself and go with it ? If i go with the shop i might as well buy a new dryer/filter. But if i do it the way suggested a few posts up then i cant replace the dryer because itll leak out what r12 i have left in the system.

I never evaced the system when i bought the Jeep. Just put two cans in and it worked for 3 years. Then refilled with 1 can and it worked again for 2 years until the compressor siezed.

Since it leaks slowely i dunno if a full evac is worth it or not because its basically letting in air anyway. Seems to need 1 can every 2-3 years.

Im gonna buy the guys other can in the next day or two. So ill have 4 on me. Should hopefully last me 6 years or so i hope

[sirrus]

Where did you buy those ? What brand ect. The ones im finding on amazon have terrible written reviews.. yet have 5 stars all chinese paid reviews it seems. Deff dont want to puncture a can and lose all of it.

Got it off eBay for $30ish. It was NOS, but even on pictures it looked better than all new Amazon crap. Brand is Interdynamics, I think it’s made in Taiwan.

[candymancan]

Thanks

[letank]

the $100 shop fee might help you locate the leak... which may cost you a little extra in the end, but with a peace of mind to avoid a ruptured hose and loosing all that R12...

When I was did mine w R134, all was good until I started to add the refrigerant and a hose blew open... spraying oil all over the passenger side of the engine

[SJTD]

I think the hoses are the time bomb on a 30 year old system and are prolly the leak.

If you close off the rest of the system with the service valves you can evacuate the pump before opening the valves and you really have no need to change the drier.

You can get an air powered vacuum pump that'll draw it down to 27 inches or so but Idunno how big a compressor you need for that. Not much air left in just the compressor after that. If you think it's too much you could break the vacuum with Freon from the can giving you a mix of mostly Freon and a tiny bit of air then suck it back down. You would then have a minute amount of air in it. Prolly less than with a pro-fessional vac pump.

If the pump failed one wonders what it did to the rest of the system? You could put in a new one and destroy it with shrapnel from the old.

Aint AC fun.

[Dave Jeeper]

When you remove the old pump you can take it apart to see if the valves broke. They are sheet metal. If they are intact then you don't have to worry about shrapnel.

I have the 2.5 cfm single stage vacuum pump from Harbor Freight and I am very happy with it. $90 plus tax. It runs off 120vac.

[candymancan]

I was planning on taking thr pump apart to see how it broke. My suspicions are it brok due to low refrigerant and low mineral oil. I already know where my system is leaking from.

Its from the low side hose. 2 inchs from the valve actually. There is a slight buldge there with a slit in the hose. And thr hose is slightly mushy all around. I can see th3 mineral oil leak there.

But i havent blew the hose yet and tbh its too much of a hassle to drop the entire dash to replace the hoses on the condensor. Ive actually been debating going to the jy and slicing up the hose in the 79 there. And wrapping that around the buldge and clamping it down. You may think thats silly. But ive done this before on metal pipes for an a.c and it worked to stop leaks. Never tried it on soft tubing but hey ?

Im litterally wanting to spend as less money as possible. Thats why i didnt even buy a dryer. And a 95$ compressor.. If it blows up i didnt lose out on alot of money.

My risk here is losing 100$ and two cans of r12. Or spending 500$ on replacing the comoressir. Dryer. Evap. And hoses and having to pay a shop to vacuum it.

I dunno if i even should bother having this shop vacuum my system. With a leak on the hose.. i lose 1 can of r12 every 2 years. Doesnt that leak just allow air in the system again ? Since my a.c was empty when i bought it.. doesnt that mean it was full of air anyway ? I didnt vacuum it. I just shoved two cans in it and it worked fine for 5 years. Refilling it once in between

Can anyone answer that question ? Should i bother having it vacuumed and replacing the dryer. Or should i go the cheap route and just refill it and go with it. Lol.

I think sjtd just said refill and go with it basically lol. And thats what im leaning on.

Dave Jeeper. Yea i was thinking of getting the same vacuum pump myself. But does that pump have r12 fittings or do i gatta buy those sepertly ?

[rocklaurence]

I've replaced several compressors over the years and never worried about the 3oz of oil in the compressor. I filled the unit up with Ester oil enough that with the 3oz from the factory it equals 11-14 oz total. However, I did screw up because over the years and removing the compressor and recharging I always used Gas with oil. Dont do it! Only add one can with oil total because more will fill the circuit with oil and hydro-lock the compressor.

[candymancan]

I wasnt going to fill with oil ina can. I bought a 32oz oil bottle a quart basically of mineral oil on amazon. I plan to drain ny compressor like someone mentioned in a cup.. and drsin the pag 46 out of this new compressor. Then pour in the mineral and turn the compressor by hand to mix it up. Then drain and repeat that again to try and get most of that pag oil out. I cant think of any other way to flush the new compressor other than this ?

Then based on how much oil drained out of my old compressor. Im going to refill the new one with that much oil. Probably 1-2 oz more though as oil has been leaking out for years.. just not sure how much though. According to a chart i found 89-91 uses only 4.5oz of oil. And 32oz of r12.

Then close the nut and hook it up and refill with r12. I have a feeling my system is very very low of r12. Ill probably be using two 14oz cans. I have no gauges either.. so ill have to go by the sight glass i guess

[SJTD]

That's a decent plan to flush the new pump. Do it as many times as you can with what you have saving what you figgered you need to put back in. When you drain yours drain both the case and the head. There's oil in both. And when you flush the new one flush both.

If you don't want to or can't suck the air outta the pump you could bleed some refrigerant in to it up to system pressure then vent it to to get most of the oil/moisture out of it. Do it slowly and you probably won't get liquid in which would waste your spensive R12.

I think charging by the sight glass is ok. That's what it's there for.