DIY Recharging of A/C?

[thscott]

I am considering "topping off" the R-134a refrigerant in my 1999 3.8 L Windstar's A/C to see if that will improve the cooling performance.

Any advice/concerns about doing this myself using one of those DIY recharge canisters? I assume I just hook it up to the low pressure service valve and use the canister's gauge to get it to the correct pressure. What is the correct pressure?

Thanks in advance.

[12Ounce]

Only consider doing this if the system has significant refrigerant remaining, and only needs "topping up".

I like to use a filler with both a trigger valve and gauge. The trigger valve allows bleeding to purge the connector hose, clearing it of air, as you are hooking up.

As you are filling, its the lowest reading that you see that matters ... just before the clutch falls out (assuming it is cycling). As the needle dips to its lowest point, it should read 25psi (and slightly more) on most warm days.

If you do a search, you will find lots of info.