dummy DIY A/C recharge questions

The A/C in my Tacoma was working well for years until it randomly quit altogether a year and a half ago. I found a hole in my AC condenser line from the chrome bumper cover rubbing against it for however long.

I am planning on replacing my condenser, dryer, and related o-rings then pulling a vacuum with a parts store loaner vacuum pump.

Assuming that the system holds vacuum without leaks and I let it vacuum to the atmosphere for a while to evac any moisture and crap in the system, will I be good to recharge with off the shelf cans of R134?

should I re-add any oil for the compressor?


@Sperrunner @Speedytech7

 

You might need like an ounce or two of oil (your FSM will say how much per component replaced) but yeah sounds like a good plan to me.

 

Yeah FSM will tell you how much oil is needed. Its possible alot got released when the hole was made.

Pulling a vacuum for atleast 45min (or till the smoke stops coming out the pump is a better indicator) you should be good.

Then just charge with the proper amount

 

a little oil on the orings helps the pieces slide together easy and not roll the o ring off. Make sure you get the correct oil for your system... they make different PAG oils.

 

Guages and a inert gas like nitrogen will allow you to pressure check before pulling a vacuum

 

This video is a long one but I think you'll find it informative to recharge your system. I watched many AC recharge videos and they still left me with some questions so I decided to do a lot of research and put this video together. If you have the patience to watch it, you'll learn a lot. Absolutely add in the recommended about of compressor oil that the FSM recommends for the condenser replacement. Another good thing is to add some UV dye into the system so it will be easier to locate any future leaks.

The right way to do the system refill is with a manifold gauge set. I don't know if auto parts stores rent these. Using the auto parts stores cheapo refill kits can work, but I wouldn't recommend it. Relying on one of those cheapo gauges for the low pressure reading and then not knowing what the high pressure side is doing isn't close to being an accurate procedure.

https://www.youtube.com/embed/zlRE0Zeeyrc

 

I followed this post when I rebuilt my system. It says how much oil and where to add it. https://www.tacomaworld.com/threads/1st-gen-a-c-system-replacement-how-to-seized-compressor.293204/

 

I just replaced a compressor (this week) that the previous owner burned up due to a lack of oil. The compressor would barely turn when I got it. I can only guess that the previous owner used a parts store recharge bottle without regard to oil. On some of my other cars, I have drained/flushed the systems replaced the receiver and compressor oil so I could be sure the system had the proper oil amount. These systems are well over 20 years old and still cooling well. It's like anything else with a car, good maintenance keeps it running for a long time.

Here's a picture of a compressor that was damaged from running the system without oil.



The vacuum pump that I use to evaluate the systems.



Guage settings during evacuation. After I pull a vacuum for an hour, I close the valves and let it sit under vacuum for an extended amount of time to verify there are no leaks.

 

Myself I have to wonder about the system being open that long .

Your replacing the condenser but not the evaporator you might get lucky.

I learned this the hard way

 

You think the evaporator has gone bad?

 

if you replace the condenser replace the dryer. any time the system is open replace the dryer. (fsm has oil capacty for each part replaced, oil can be had at napa) then pull a vacuum and make sure it holds. once youve done that you should be good to charge with freon in a can. careful not to overcharge mind you

 

It all depends if moisture / being open to the Air got into the evaporator in the climate I have here in Pa it would be a given.

Your Climate might just be dry enough not to be as bad .

Being you have changed all the other mechanical parts in the system.

Best of luck

 

I replaced the condenser and the dryer and pulled a vacuum on the system for 45 minutes. I also let the system stay in vacuum and it held for 45 minutes as well.

Unfortunately it seems like I will need to evac the system and change the evaporator and expansion valve. After charging the system runs and cools but it doesn't get very cold.

 

what are the low and high side pressures, what is the temp out the center vent? verify that the recirculation/fresh air door is in recirculate position, the hot cold flap flips from heat to cool and the heater control valve actually shuts off... just because the lever on the valve moves does not mean that hot water isn't circulating. I am going to think out loud... if the expansion valve is not opening far enough or there is too much refrigerant in the system I believe that those would be your symptoms.

 

At an ambient temp of 72F last night the low side was 35 psi and the high side was 175 psi

 

Any chance you over charged it?

When the system is running, is there any condensation on the Compressor?

 

I don't see any condensation on the compressor but it's hard to tell. Given the pressure readings I don't think it's over charged

 

I checked the heater control valve and it does seem to be closing off coolant flow.

What does it mean if the dryer sight glass goes milky? Moisture still in the system?

While the system is off the glass is good. If I run a hose over the condenser while the AC is on it stays good like this



If I turn the hose off of the condenser it goes milky white after a bit

 

Temp at vent is 52.5 deg F on recirc and medium fan.

It's 92deg F outside, maybe all is well and I'm just expecting too much?

 

Humidity matters more. 52.5 at 92 isn’t too bad though