Do I really need to use the 134a first charge

[bnrr]

I really need a good advice about using or charging my a/c system with a first charge refrigerant after replacing the system with new compressor and hose lines, and accumulator.etc.. my friends say that it is okay to use any refrigerant recharge. but then I am skeptical because the refrigerant charge all contain stop leaks and so on. to make things harder for me is that the first charge refrigerant are not available where I am from. is this okay, or a no, no please help, I am a newbie with no knowledge of any kind of refigerant charges.

Thanks

 

[88ranger89camaro]

well to be honnest you need to run a vacuum on it for no less than a few hours, then hit it with an oil chage with your freeon

but on the other hand if you use a oil charge and the "X" cans of freeon you should be ok, its not proper but it will work

 

[mp3deviant721]

If your system has been open, its a good idea to pull it on a vacuum to pull out air, moisture, etc, pretty much all the junk you don't want in there with the refrigerant. Get it charged by a shop though if you don't have the equipment or access to equipment. Stop leak in an A/C system is a bad idea. Some shops won't work on systems that have stop leak in them in fear of damaging their machines with that stuff.

 

[bnrr]

hey guys thanks for the replys to my post. today I did a vacuum on my system and after running it for 30 minutes it only reach up to a 17.9, does this mean that I need to run the vacuum for more than 1 or 2 hours to reach the normal readings of 29.9hg? also I waited for 5 minutes after turning the pump off, and the readings drop from the 17.9 to 0 in 3 minutes. what dose this mean? is more of leak issue.
my pump is a FJC 2 stage 3cfm and a mastercool digital manifold guage.
Thanks

 

[kimcrwbr1]

It could be old refrigant in the oil you should do a pressure test with nitrogen to see if there is any leaks first before you add refrigerant. Pressurize it with 200 lbs psi of nitrogen and let it sit for 45 minutes if the pressure dont move pull it in a deep vac for 45 mins and then add your charge. If the pressure drops use soap while under pressure to locate the leak. 1/4 inch of dish soap in a spray bottle and fill with water works just fine small leaks can be hard to find so spray everything good and a little mirror will help look in the hard to reach places.

 

[bnrr]

kimcrwbr1, thank for the tech tip/advice. I am going to give it a try, but first am going to have to see if I could get a hold of nitogen, if not I am just going to go ahead and try with the vacuum pump. Thanks...

 

[4x4junkie]

It not holding a vacuum is also indicative of a leak.

Additionally, if you're at anything above sea level, attaining 29.9" hg vacuum will be impossible, however even at 3000ft, you should still be able to reach a little under 27" hg at that elevation.

 

[bnrr]

ok, if I could just get a little as 17.9 hg, would you say that this is safe or better yet just get the leak fix. but let's just say that I fix the leak I still get the same readings just below 20hg would that be ok? but now I am just thinking that the vacuum pump (FJC 3cfm) that I am using taks more time to do a deep vac on the system. what do you think?
any comnment from TRS community would be very helpful.

Thanks

 

[mp3deviant721]

Fix the leak. There's no point in charging it if it is leaking.

 

[4x4junkie]

Your stating that it loses all vacuum after 3 minutes undeniably says you have a leak (and a big one at that!). Now if that leak is within the system itself or maybe within your gauge set I have no way of knowing, however regardless of where it is, this is something that ABSOLUTELY has to be fixed or eliminated if you're to put a proper charge into the system.

At this point I'd probably suggest you take it in to an A/C repair place before you waste a bunch of freon, or worse, cause damage to other parts in the system. They'll have the knowledge and equipment to deal with whatever the problem is (and will also know what repair parts to order if needed too).

 

[kimcrwbr1]

In home heat pumps and a/c we measure the vac down in microns and only after it passes a pressure test do you vac it down if you have a leak your just pulling moist air into the system. A single drop of water will destroy the compressor from the acid it produces. The reason you vac the system down is to remove all non condensable gasses, when you reach a deep vacuum it boils the water down to gasses and removes them it could be you still have moisture in the system if it mixes with the oil it can take a long time to remove. If you left the system open to ambient air for any amount of time it pulls moisture in with the rise and fall of barometric pressure. I am not sure where you get nitrogen and a regulator but we test our heat pumps at 450 psi for 45 mins but you can just use the operating pressure of your system to do the pressure test, make sure your guages are not leaking and soap everything good do a low pressure test 50 psi 15 mins first soap test and then take it up to high pressure. Small leaks are hard to find and it just takes a small leak to lose the vac down real fast. If it passes the pressure test put it on deep vac overnite if necessary to remove all the moisture. whenever we open up a system it is a crap shoot on how long it takes to vac it down after the repair is done but being how small your system is the time should be alot less with a good vacuum pump.

 

[bnrr]

hey, everyone thank you for the tips and guideance with my a/c issues. yesterday I decided to roll up my sleeves and get my fingers really dirty by starting from scratch again by taking the a/c system apart. real efforts really pays off. I have found the leak on the a/c manifold tube that goes from the compressor to the drier. my goodness there was a long scratch on the rubber part that is at least 1/2 inch long in which I notice or at least could see little pinholes. I did not notice that damage before because it happen under the hose where I could not see it at all. this damage happen on my part, while I was routing the hose thru the pathway of the water pump, and I guess it got damage by hitting something during the installation. I am going to purchase another a/c manifold assembly and tube, becuase the only way it to replace it (again). the valuabe leasson that I have learn here is; pay attention during installation and be very carefull with the parts, they can get damage very easily and the most very important thing (for me that is) do not get very emotional or excited when nearing a job completetion.
Once again thank you everyone for the step by step leassons.

 

[press 1 for english]

If your system has been open, its a good idea to pull it on a vacuum to pull out air, moisture, etc, pretty much all the junk you don't want in there with the refrigerant. Get it charged by a shop though if you don't have the equipment or access to equipment. Stop leak in an A/C system is a bad idea. Some shops won't work on systems that have stop leak in them in fear of damaging their machines with that stuff.

A vacuum pump will not remove any moisture unless you leave it running for 12-24 hours to pull a vacuum deep enough where the moisture boils off and out. 1/2 hour on the vacuum pump and you should change the filter/drier/accumulator every time you open the system.....that is what really removes moisture.
Stop leak is worthless and if you half ass a/c repairs, it will come back and bite you.