AC recharge

[faderjake]

hey guys, my AC has been dead for awhile now, so i went to wally world and picked up the charger with the gage on it. i started to refill it i have a quarter of the bottle in and the gage builds up psi to 40 then drops to 0 and the pully kicks on and off while this is happening.... so i stoped filling it, any ideas why it dose this? should i keep filling it up?

 

[tjkj2002]

Take it to a shop for AC work,you skipped about 5 steps before you even begin recharging the system.

 

[faderjake]

nope dident skip any steps followed the derections on the bottle and youtubed it just to be safe. it shouldent take a shop to refill the ac. i was wondering if the ac was prolli so low that it would do this to restart itself.

 

[Ry' N Jen]

Take it to a dealership or shop that can recharge A/C systems. Those DIY kits are just designed to suck money out of your pocket and pollute the atmosphere with more crap! Like Troy said, you skipped several steps!
Get an FSM and you will understand what and why!

 

[tjkj2002]

nope dident skip any steps followed the derections on the bottle and youtubed it just to be safe. it shouldent take a shop to refill the ac. i was wondering if the ac was prolli so low that it would do this to restart itself.

Well you missed evac'ing the system and then pulling vacuum for 30-60mins.Then adding tracer dye and then adding the correct amount of R134A(by weight) then using a AC gas leak detector and/or UV light to check for leaks.Find leaks,evac system again and pull vacuum,fix leak(s),pull vacuum again and recharge system with correct amount of R134A.The correct way to fix your AC system.

It's not easy or quick by anymeans and the tools required can be very pricey.

 

[BjBnet]

Well you missed evac'ing the system and then pulling vacuum for 30-60mins.Then adding tracer dye and then adding the correct amount of R134A(by weight) then using a AC gas leak detector and/or UV light to check for leaks.Find leaks,evac system again and pull vacuum,fix leak(s),pull vacuum again and recharge system with correct amount of R134A.The correct way to fix your AC system.

It's not easy or quick by anymeans and the tools required can be very pricey.

You just always think you know it all don't you! I like that!! :happy175:
Always appreciate your input when it comes to stuff like this.
I've looked at some of those DIY kits and was a bit skeptical...now I know

 

[tjkj2002]

You just always think you know it all don't you! I like that!! :happy175:
Always appreciate your input when it comes to stuff like this.
I've looked at some of those DIY kits and was a bit skeptical...now I know

Well I do this crap for a living:smokin:,and hate every min of AC work as it's such a worthless thing to have in a vehicle anyways.

ASE certified,MACKs certified,and EPA certified for automotive AC repair work.I can legally buy R12(the real stuff,not that freeze12 junk) also:smokin:.

 

[retmil46]

Well, he may not have needed to evac the system if he still had a reasonable amount of pressure in it to begin with - he didn't state one way or another - but from the sound of it looks like it was bled down completely for the compressor to act like that.

Other steps I agree with - if the system hadn't been working because some of the charge had leaked out, UV dye and checking for leaks is called for.

Those recharge cans with the cheap-a$$ built-in low pressure gauges are worthless - you need to be able to read low AND high pressure sides while operating at a specific engine rpm, then compare those against outlet air temp from the center vent and ambient air temp, to determine what's going on with the freon side of the house - for the price of two of those recharge cans with the built-in gage, you can get a satisfactory set of manifold gauges which also includes the recharge hose - allowing you to buy the plain-jane cans of freon for 9 bucks and change - AFTER you've figured out what's going on.

Don't have the automotive cert, but have had the EPA Universal cert for stationary applications since '94.

 

[tjkj2002]

Yeah but we must evac the system 1st so we know how much R134A was in the system to start with as our AC diag service is $80 plus the cost of R134A.So if I pulled 10oz of R134A out of your system and your system holds 24oz of R134A you only get charged for 14oz of R134A.Helps determine how big the leak is or if there is even a leak to begin with also,saves the customer $$$.

 

[LibertyTC]

Interesting!
Does the system require some sort of additional oil with the R134A?
Where does it get added?

 

[tjkj2002]

Interesting!
Does the system require some sort of additional oil with the R134A?
Where does it get added?

Generally no system oil is removed when evac'ed,only when components are replaced(evap,condensor,receiver/dryer,and compressor).Must use PAG oil and generally add specific amounts to each component,you add tracer dye through the low side port.

 

[retmil46]

Generally no system oil is removed when evac'ed,only when components are replaced(evap,condensor,receiver/dryer,and compressor).Must use PAG oil and generally add specific amounts to each component,you add tracer dye through the low side port.

Agreed. Also, if you pop the hood, the sticker on the radiator crossbrace lists not only the type and amount of freon for a full charge in the system, it also lists the type and amount of oil needed as well, depending on which type compressor you have - there's two listed on the sticker on my 05 CRD, the first one is for gassers, the second one (which has a part number something like PDX-***) is for CRD's.

From what I understand, on older vehicles that have had their R-12 systems converted over to R-134, you still need to use Ester oil with the R-134, as PAG oil will seep thru and degrade the original hoses that were designed for a R-12/Ester combination.

On my first used 87 MB 300D that I bought in 06, there was a sticker under the hood where the system had been shop converted over to R-134, listing the amount of freon, and that they'd used Ester oil and that amount as well. Those beasts have large A/C systems on them - original R-12 charge listed in the MB FSM is 1.1 kilograms - close to 2 1/2 lbs. Even converted over to R-134, that system was idling with the blower at half-speed to keep that car cool on a 103 F Texas day with 50 F air out of the vents.

 

[VeitzJeep]

FYI, there is such thing as too much Freon. If you go over the factory recommended amount, you're just adding pressure to the AC systems and that pressure causes the temperature to increase.

 

[retmil46]

FYI, there is such thing as too much Freon. If you go over the factory recommended amount, you're just adding pressure to the AC systems and that pressure causes the temperature to increase.

Agreed. That's why it's important to use a set of manifold gages, to read low and high pressure, and do the system performance check in the FSM - to determine if you have too little, too much, or the right amount - if the right amount and you're still having issues with your A/C system, then you need to start looking at other potential causes.

 

[VeitzJeep]

Well said, Ret.

IMO, with all of the guages you need and handling chemicals that can be dangerous and harm the atmosphere, it's probably better off just to go to a professional for the AC recharge. If there's any parts that need replacing, by all means do it yourself if you want, but I don't like the idea that Freon is as readily available as it is because there's a lot of people who don't know what they're doing who will just mess things up. They're selling these things at Walmart like just because it's summer, you NEED to add Freon.

 

[tjkj2002]

To much R134A,over-charged system,can allow liquid R134A to reach the compressor and you can not compress a liquid so something will blow and it's almost always the compressor.

 

[flair1111]

go to the shop as tjkj2002 said. its well worth it.

 

[Ry' N Jen]

FYI... 1.1 kilogram = 2.425 pounds.