Rear a/c leak

[08navigator]

You can pour the oil in anywhere. If the compressor was removed or replaced it would be mandatory to add it there but since your just repairing a leaking line. Pour it right in the line you have open.

This sounds like it should work. If I put 1.5oz of pag oil in the line I'm replacing, will the vacuum pump pull it out or not bother it?

Sent from my Pixel XL using Tapatalk

 

[TobyU]

Vacuum pump won't remove it if you put on line as that's a long way from the ports you are vacuuming from. If you shoot it in with a small pressurized can of pag46 you will do it after the pump down.
You can even do repair, hook pump up to high (small line) side then use charging hose or gauge hose to hook to low side one stick other end into oil. Using red side gauge handle valve to control suction.
Then after oil is in hook hose end to manifold gauge and open red high side valve again full open for 4-5 mins before opening blue low side.
When pumping down always open valves all the way.
I reach down and manually turn comp over by hand 10-15 times to displace any air in the up to six pistons they have.

 

[Motorcity muscle]

Lot of bad info in this thread, liquid refrigerant and oil will damage skin/eyes. Be safe, wear gloves and goggles. Best way to check for leak after repairs is with nitrogen. If air/moisture is left in a closed refrigeration system it will create acid and damage compressor. Could make repairs and have system charged at shop.

 

[gixer2000]

Lot of bad info in this thread, liquid refrigerant and oil will damage skin/eyes. Be safe, wear gloves and goggles. Best way to check for leak after repairs is with nitrogen. If air/moisture is left in a closed refrigeration system it will create acid and damage compressor. Could make repairs and have system charged at shop.

How many people doing this work at home have access to nitrogen or a regulator? Sure, anyone can go buy one but not everyone has the funds to do so.

As for leak testing the best way is actually in a vacuum with a micron gauge. A vacuum decay test would laugh at a pressure test and can be done much faster than a pressure test. A legit pressure test should sit for 24hr while a decay test with a micron gauge takes an hour once its below 500 microns.

I find more leaks in commercial and industrial equipment with a decay test over a pressure test but again, not equipment the home mechanic owns.

As for acid being formed from air and moisture being left behind. Automotive AC compressors aren't affected by acid like a traditional compressor that runs on AC or DC voltage is. The acid actually breaks down the coating around the motor windings causing a short within the windings. Automotive compressors don't have have windings and the acid doesn't eat steel, brass, copper or aluminum so....

I am in no way saying its ok to purge refrigerant before charging or to skip a vacuum but when the equipment isn't available you do what needs to be done because in an automotive application, it will work!

Always wear PPE! Glasses and gloves are important

 

[bobmbx]

How many people doing this work at home have access to nitrogen or a regulator? Sure, anyone can go buy one but not everyone has the funds to do so.

As for leak testing the best way is actually in a vacuum with a micron gauge. A vacuum decay test would laugh at a pressure test and can be done much faster than a pressure test. A legit pressure test should sit for 24hr while a decay test with a micron gauge takes an hour once its below 500 microns.

I find more leaks in commercial and industrial equipment with a decay test over a pressure test but again, not equipment the home mechanic owns.

As for acid being formed from air and moisture being left behind. Automotive AC compressors aren't affected by acid like a traditional compressor that runs on AC or DC voltage is. The acid actually breaks down the coating around the motor windings causing a short within the windings. Automotive compressors don't have have windings and the acid doesn't eat steel, brass, copper or aluminum so....

I am in no way saying its ok to purge refrigerant before charging or to skip a vacuum but when the equipment isn't available you do what needs to be done because in an automotive application, it will work!

Always wear PPE! Glasses and gloves are important

I've never drawn a vacuum on any of the a/c systems I've cracked open. Just re-charged. Never had a problem.

 

[gixer2000]

I've never drawn a vacuum on any of the a/c systems I've cracked open. Just re-charged. Never had a problem.

That's basically what I was explaining to the person I quoted. Sure, its not the right way but you work with what you have. Even though I don't agree with the method it does work

 

[TobyU]

Exactly why I specified in my post that it's a very variable procedure in working on AC Automotive Systems. What was the right way 20 years ago is no longer considered the right way. For some people the right way is whatever way gets the job done and works.
Very few people worry about R12 or R134a getting on your skin they worry more about frostbite from it blowing off. Of course it's not a good idea to get it on you repeatedly but doing one repair one time on a vehicle is completely different than a tech doing it all summer long. You basically just wipe it off your hands with a towel. Yes, the frost could damage your eyes to but once again very few techs wear safety glasses from working AC systems. If a line were to happen to blow off and vent refrigerant you just turn your head real fast. That's how most of the world techs do it.

Hardly anyone or any shops use nitrogen for automotive pressure testing. That is a commercial and residential procedure. Automotive pumps them down and uses a micron gauge as stated by a previous poster.
I don't think I've seen any bad information in this thread.
You can leave an AC compressor sitting on a shelf for years and still put it on a system pump it down it will work just fine. The only thing that is sensitive to moisture are the receiver dryers and dryers in the accumulator / AV bottle. It is of course better to only leave a system open for his little time that you have to.

 

[08navigator]

I already purchased the vacuum pump. I will Purge the air out of the charge line prior to charging. If I pull a vacuum on the system the water should boil off. I do not have access to nitrogen and the only way I'll be checking for leaks is with dye after charging it. I'm buying the equipment to charge it myself for a few reasons. 1. If it leaks I can try again and it will only cost me some more 134a. 2. I can use it on my other vehicles. 3. I don't have a three. Just because I guess.

Thanks for the info everybody. I love hearing from as many as possible since everybody does it differently. I know I could probably get by just charging the system but for the minimal investment I would rather vacuum the system down and do it right.

Sent from my Pixel XL using Tapatalk

 

[gixer2000]

I already purchased the vacuum pump. I will Purge the air out of the charge line prior to charging. If I pull a vacuum on the system the water should boil off. I do not have access to nitrogen and the only way I'll be checking for leaks is with dye after charging it. I'm buying the equipment to charge it myself for a few reasons. 1. If it leaks I can try again and it will only cost me some more 134a. 2. I can use it on my other vehicles. 3. I don't have a three. Just because I guess.

Thanks for the info everybody. I love hearing from as many as possible since everybody does it differently. I know I could probably get by just charging the system but for the minimal investment I would rather vacuum the system down and do it right.

Sent from my Pixel XL using Tapatalk

The vacuum will boil off any moisture left behind but I would let the vacuum run for a while. You really can't put a time on a vacuum but give it as much time as you can since you really have no way to measure it accurately

 

[TobyU]

I always like to pump them down for at least 25 to 35 minutes if they've been open for any length of time. Ideally 45 is even better. If they have only been open for a few minutes while I am doing a repair like replacing an orifice tube or something like that then I'm simply pumping them down for less than 10 minutes just to get rid of the outside atmospheric pressure.

I repair the AC systems for decades replacing compressors and charging without fully understanding the way the system really works. Things like the high-side and low-side, liquid line suction line. Without really understanding that the all the high pressure lines are not liquid and understanding the phase change and the direction and path that the refrigerant takes through the system and when and where things occur.
None of that really matters when you just need a leak fixed or a new compressor installed but it does help in diagnosing weird gauge readings on systems.

 

[Retiredusps]

I hate to break your Bubble but that line is only rated for 35 lbs on the web site. Maybe you are going to do all that work for nothing. Why not check out a HVAC supply house!! Hate to see you go thru all that work and blow the line out. I think all tubing for ac is thick wall.

 

[gixer2000]

I hate to break your Bubble but that line is only rated for 35 lbs on the web site. Maybe you are going to do all that work for nothing. Why not check out a HVAC supply house!! Hate to see you go thru all that work and blow the line out. I think all tubing for ac is thick wall.

An HVAC supply house will sell him copper and nothing else. I haven't researched the tubing he's using so I really can't comment on what it will handle

 

[08navigator]

I hate to break your Bubble but that line is only rated for 35 lbs on the web site. Maybe you are going to do all that work for nothing. Why not check out a HVAC supply house!! Hate to see you go thru all that work and blow the line out. I think all tubing for ac is thick wall.

Where do you see that? They sell a smaller wall thickness one for cheaper but this wall thickness is pretty much spot on with stock and it's double the thickness of the cheaper stuff.

Sent from my Pixel XL using Tapatalk

 

[08navigator]

I hate to break your Bubble but that line is only rated for 35 lbs on the web site. Maybe you are going to do all that work for nothing. Why not check out a HVAC supply house!! Hate to see you go thru all that work and blow the line out. I think all tubing for ac is thick wall.

I think your looking at the .035 wall thickness tubing. This is .070 thickness.

Sent from my Pixel XL using Tapatalk

 

[Retiredusps]

I went by the part number you listed.Unless I made a mistake. I found this site that sells a lot of Kits and a/c parts. Nostalgic AC Parts Complete Universal R-134a Hose Kits

 

[08navigator]

I went by the part number you listed.Unless I made a mistake. I found this site that sells a lot of Kits and a/c parts. Nostalgic AC Parts Complete Universal R-134a Hose Kits

It looks like somebody has it listed wrong on their website. If it's not .070 I'll return it and look elsewhere. What website did you find? I'm new to all of this so all help is appreciated.

Sent from my Pixel XL using Tapatalk

 

[TobyU]

As long as it's aluminum and about the same thickness as the factory it will probably hold but those pressures do exceed 250 psi. That 35 psi rating is much much much below the burst strength and they're just saying that to be very cautious. Think about it. Even aluminum tubing that you could been with your pinky finger would still hold 80-100 PSI before it would rupture.
In all reality you could use some of the Rhino guard steel fuel line from the parts store or the Cunifer stuff if it were the same diameter and using compression fittings to fit. The inside is not going to rust this going to be coated in oil all the time anyways and the outside has that green coating which you can paint over and would more than likely Outlast the time you're going to own the vehicle. At a point like this it's all about getting the vehicle cool. If you can do repair in a couple of hours and get by 3 years plus then it's well worth doing even if you might have to do it again. You need that air conditioning.
You could even try to push a piece of rubber high pressure AC line of the appropriate size over your existing line and triple clamp it. I want to be slid on at least three inch minimum and then triple clamp with the clamps rotated in different clock positions around the line. I really don't trust these unless there is a barbed end. An ac or radiator shop could braze you a barbed end right onto the place where you cut it off at.
If the aluminum you get is fairly stiff and hard to bend it will probably be just fine.
If it splits open you'll just have to do it again.

 

[08navigator]

As long as it's aluminum and about the same thickness as the factory it will probably hold but those pressures do exceed 250 psi. That 35 psi rating is much much much below the burst strength and they're just saying that to be very cautious. Think about it. Even aluminum tubing that you could been with your pinky finger would still hold 80-100 PSI before it would rupture.
In all reality you could use some of the Rhino guard steel fuel line from the parts store or the Cunifer stuff if it were the same diameter and using compression fittings to fit. The inside is not going to rust this going to be coated in oil all the time anyways and the outside has that green coating which you can paint over and would more than likely Outlast the time you're going to own the vehicle. At a point like this it's all about getting the vehicle cool. If you can do repair in a couple of hours and get by 3 years plus then it's well worth doing even if you might have to do it again. You need that air conditioning.
You could even try to push a piece of rubber high pressure AC line of the appropriate size over your existing line and triple clamp it. I want to be slid on at least three inch minimum and then triple clamp with the clamps rotated in different clock positions around the line. I really don't trust these unless there is a barbed end. An ac or radiator shop could braze you a barbed end right onto the place where you cut it off at.
If the aluminum you get is fairly stiff and hard to bend it will probably be just fine.
If it splits open you'll just have to do it again.

That makes sense. For the minimal cost I'll give this stuff a try. I'll have the vacuum pump and manifold if I ever have to do it again. Parts should arrive this week. I'll update this thread with the outcome. Thanks again!

There's actually a company out there who makes rubber hose replacement lines for these suvs. I called and they said they hope to have the line for the expedition before summer this year.

Sent from my Pixel XL using Tapatalk

 

[Retiredusps]

The site I sent you has kits with i think are sections of the rubber hose and a assortment of fittings.maybe you could use rubber and go up inside the back panel and start from there.You will also need a new dryer they suck up moisture like crazy. If you do not replace the unit is likely freeze up on you, then defrost and start working again.If it was me I would start in the rear compartment with metal or rubber and go forward to where you could splice in somewhere along frame rail that is easy to work on.That's just me. If you are going to go with the alum I would get a tubing bender. They sell spring ones or you can slide rubber hose over so it doesn't kink while bending.I did a few of under dash units years ago that everything was adapted to the car or truck. Try the site I posted and ask them Questions. Its only a email or phone call. No I do not have anything to do with them.Just trying to help

 

[Retiredusps]

The site I posted has kits with rubber hose with fittings,also tubing. You should also replace dryer and orifice.If it was me I would start to replace from inside to splice and go forward to a open area along frame rail that is easy to work on.I don't really remember how the connections are inside to get to. the site I sent has a lot of a/c parts and retro kits maybe call or email with you problem.The orifice is easy to change the screen gets plugged. Also make sure you get the correct color !!


Also found this site
Auto Cooling Solutions
Specializing in Rear AC replacement parts Air Conditioning
Automotive • Industrial • Heavy Truck • RV • Marine