AC Flush

[Moreflying]

What are the DIY procedures for flushing the system if needed?

I say if needed because my compressor has not failed but I will be removing my engine and taking out the AC components. In this case, is it still necessary to flush the system? I will be replacing the compressor as it is the original with a lot of miles, after my install of the new engine. Thanks.

 

[BRUTUS_T_HOG]

you don't need to flush the system unless there is debri in it. i would just unbolt the compressor from the engine and leave the system alone.

 

[Moreflying]

Okay..so even if I replace the compressor no need to flush if the system is clean? What is the best indicator of a clean set up just in case, so when I get it apart I know what I'm looking for. Thanks.

And just for my own edification, is there info on how to flush the system for the DIY guy? I searched but didn't find any good info on the site for that specific process?

 

[kimcrwbr1]

Dont open it up until you have the compressor ready to install. You dont want moisture to get in but after you change the compressor your gonna need to take it into a deep vacuum before you add the refrigerant to remove non condensable gasses(water), and add by weight the factory charge before enguaging the compressor. There is a acid test you can use for the oil to see if it needs to be flushed. You really dont need to do anything unless your having problems with the A/C. If it aint broke dont fix it.

 

[BRUTUS_T_HOG]

Okay..so even if I replace the compressor no need to flush if the system is clean? What is the best indicator of a clean set up just in case, so when I get it apart I know what I'm looking for. Thanks.

And just for my own edification, is there info on how to flush the system for the DIY guy? I searched but didn't find any good info on the site for that specific process?

when you take the lines loose from the compressor if there is ANY dirt or debris in the lines the system needs to be flushed. you'll have to replace the accumulator and the orifice tube, and flush the rest of the system.

then you'll have to have the system vacuumed down and charged with the proper amount of oil. this is all easily done whether the engine is in the truck or not so unless you want to spend the money its unnecessary

you'll need a way to pump flush solvent into the lines and then blow them clean with air. its nasty stuff

 

[sblake01]

My 90 still has the original compressor. It works. There's no real reason to change out a functional compressor simply because it's old.

 

[bilzy7]

Ya I'm gonna hafta get a shot of coolant or whatever it is lol and see if my system actually works... If so, I'll be happy.

 

[Earl43P]

http://www.autoacforum.com/categories.cfm?catid=20

Some good info in that link.

Even if you find no debris, at that point you'd be wise to replace that orifice tube and accumulator anyway. You may be forced to buy the line that the orifice tube is in, some aren't removeable (although I think yours will be, just resist the urge to twist).

http://www.autoacforum.com/messageview.cfm?catid=20&threadid=10818


Flush procedure:

http://www.autoacforum.com/messageview.cfm?catid=20&threadid=9172

 

[Moreflying]

Thank you for the info guys. After reading some of the tech sites im not so sure about the proper recharge with cans with regard to pressure vs temp as well as correct oil. Is it possible to recharge affectively and have a lasting set up without the $3000.00 shop equipment.

 

[BRUTUS_T_HOG]

Thank you for the info guys. After reading some of the tech sites im not so sure about the proper recharge with cans with regard to pressure vs temp as well as correct oil. Is it possible to recharge affectively and have a lasting set up without the $3000.00 shop equipment.

not if you've never done it before. you need to vacuum the system down to remove moist air otherwise you will destroy the system with acid and sludge and it won't get cold.

if you were to have the system vacuumed down you can charge it yourself with the cans until it gets cold while the system is running, but you also have to replenish the oil after flushing the lines. you can add oil to the lines before you reconnect, its best to add half to the condenser and half to the evaporator or accumulator.

 

[Moreflying]

Okay so I took off the compressor clutch and the shaft has oil all over it which is indicative of a leak at the shaft. I guess 220,000 miles caught up to it. Today I went out and purchased manifold gauges, vac. pump, new compressor, accumulator, quick connect removal tool and orfice tube. I know I'll have more questions as I get into it and I appreciate you guys helping me out. I think I might wait until I get the new engine in before doing the AC as I'm not sure I can get the engine out without disconnecting AC. I excited about learing a new aspect of auto repair.

 

[4x4junkie]

The compressor needs oil in it right away.

When I did mine, I put 4 oz oil in the compressor, the rest into the accumulator (spin the comp rotor by hand to make sure the oil is distributed through it before engaging it).



Read read & read. If you got a vacuum pump and a set of gauges, you can do it yourself, though one mistake and it'll likely be all over for your system (a damaged compressor will spew debris throughout the system, which typically forces you to replace the condenser as well, as it's extremely difficult to flush it all out of the serpentine-flow design it uses).

The site Earl linked to is an awesome resource for AC info. Together with a Haynes book on AC service (can be had at any autoparts store), I found everything I needed to know about service procedures when I did a R-134a conversion on my BII a few years ago.

Just be sure when you buy your cans, make sure it doesn't contain any "leak sealers" or "seal conditioners" or other crap that can clog up your orifice or gum up the system. You just want straight pure R-134a, plus your PAG oil (UV dye and "ICE" (IIRC) performance treatment is OK, at least according to a service tech I spoke to, though I don't think the treatment is absolutely necessary. I didn't use it on my Ranger when I had to replace a hose and it seems to blow just as cold as my BII does).

 

[Moreflying]

The compressor needs oil in it right away.

When I did mine, I put 4 oz oil in the compressor, the rest into the accumulator (spin the comp rotor by hand to make sure the oil is distributed through it before engaging it).



Read read & read. If you got a vacuum pump and a set of gauges, you can do it yourself, though one mistake and it'll likely be all over for your system (a damaged compressor will spew debris throughout the system, which typically forces you to replace the condenser as well, as it's extremely difficult to flush it all out of the serpentine-flow design it uses).

The site Earl linked to is an awesome resource for AC info. Together with a Haynes book on AC service (can be had at any autoparts store), I found everything I needed to know about service procedures when I did a R-134a conversion on my BII a few years ago.

Just be sure when you buy your cans, make sure it doesn't contain any "leak sealers" or "seal conditioners" or other crap that can clog up your orifice or gum up the system. You just want straight pure R-134a, plus your PAG oil (UV dye and "ICE" (IIRC) performance treatment is OK, at least according to a service tech I spoke to, though I don't think the treatment is absolutely necessary. I didn't use it on my Ranger when I had to replace a hose and it seems to blow just as cold as my BII does).

Yes...I'll be reading up on the ins and outs for sure. Thank you for your input on the situation. I'll make sure to get just the R-134A with no sealant. I'm not sure what PAG in need yet. I was thinking it was 100. If you think of any pitfalls or mistakes a new guy to AC can make please let me know. I will share what I've learned too. I figure by the end of the summer I'll be able to say if my job worked out or not. Off and reading

Here's the factory sticker off my evaporator housing. It's nice to be the original owner and still have little things like that to help.

 

[BRUTUS_T_HOG]

Okay so I took off the compressor clutch and the shaft has oil all over it which is indicative of a leak at the shaft. I guess 220,000 miles caught up to it. Today I went out and purchased manifold gauges, vac. pump, new compressor, accumulator, quick connect removal tool and orfice tube. I know I'll have more questions as I get into it and I appreciate you guys helping me out. I think I might wait until I get the new engine in before doing the AC as I'm not sure I can get the engine out without disconnecting AC. I excited about learing a new aspect of auto repair.

you can unbolt the compressor and move it forward and down and let it sit on the frame. just remove the radiator and fan and you'll have plenty of room

 

[4x4junkie]

PAG46 oil is what's called for. For some reason I keep finding stores to be out of it about half the time (they always have the 100 though) so you might have to try a couple different places to find it.


A few tips that can help:

Evacuate (vacuum) your system while the engine is hot. Any traces of moisture in there will come out that much more swiftly & thoroughly when things are warm.

To get the freon cans to empty out quicker, place them in a pan of hot water while you're dispensing it into the system (do not invert them though).

DON'T twist the orifice tube while trying to remove it, it WILL break it. What I did was blow compressed air through the evaporator outlet port to eject the tube.

Purge the air out of your center gauge hose by loosening the fitting at the gauge set for a bit before you open the manifold valve to let the freon in (this one's pretty standard practice).

About all I can think of at the moment.

Good luck on it