AC repair advice

[RandyBobandy]

I plan to repair my AC now that it’s starting to get hot out and need some advice.

When I bought the 4Runner the ac didn’t work, I tried to recharge it but it wouldn’t take any more refrigerant so I’m guessing it isn’t leaking since the gauge on the can said it had pressure, the ac continued to not work and I just ignored it and opened the windows

Several months later I was working on something and punctured the condenser, which I also ignored since the ac didn’t work anyways. Now I’d like to replace the condenser and drier and get the AC working, I plan to flush it myself and add oil and refrigerant, I also plan to either buy or rent a vacuum pump.

My question is, do I need to do anything to make sure the compressor is good? Any tips from people who have done a diy AC repair?

I don’t really plan to take it to a shop to have it refilled unless it’s under $100, I would rather spend that money on a vacuum pump so I could also repair ac on family and friends vehicles

 

[BamaDrewski]

I think this might help you. I replaced my entire system years ago and in Alabama heat, it blows 36 degrees on the coolest setting. I did all this work 5 years ago!!! Some yahoo wanted to charge me almost a grand for a Chinese compressor install alone!

The write up shows the part numbers and where I got them. Most were Denso parts from Amazon.......If you devote a day to it, it can be done. Then, just have someone pull a vaccum on it for 30 minutes and refill with R134.

DIY Complete AC Replacement on 2000 T4R Limited

 

[RandyBobandy]

Thank you for the write up, that is very helpful, I’m wondering though do you think it is really necessary to replace everything? I was hoping to be able to just replace the condenser and maybe some O-rings along with a flush and refill, should I replace the compressor while I’m at it? I’d probably just get a used unit from eBay

Is there any way to test the compressor to see if it’s okay?

I’m confident in my ability to replace parts, it’s the diagnosis that I’m not too experienced with

 

[96RedRunner]

Hard to tell what you need since it hasn't worked for you. When you first checked/charged it was compressor clutch engaging and turning compressor?
Did you check freon flow in site glass when you first got it?
What does compressor do now if you turn AC on? If not locked up may be good.
There are system parts under hood and under dash that can go bad. You need system charged to troubleshoot. I rented a pump and guages from Harbor Freight to do mine, neither were good enough to keep long term. Good guages and pump will cost you big. To get a idea on diagnosing system try FSM. System holds 24 oz if empty, put in 12 oz can or a bit more see what happens.

 

[RandyBobandy]

I have not had the ac turned on since damaging the condenser, I was under the impression that if the system was empty it would damage the compressor if I turned it on. Is it safe to attempt to turn it on and see if it engages? I never really tried to diagnose it when I first got it

Should I just replace the condenser and charge it and go from there? And I didn’t know harbor freight had rental tools, or did you just buy them and return them

 

[Brian.]

I went through an AC system issue a couple years back too, though mine went from working to not. I thought it was just the compressor clutch, so I replaced that only to have it burn out 5 seconds later.

Generally speaking, if you don't know for an absolute Fact that the compressor is functioning, plan on replacing it. So, step one would be to identify if the compressor is functional. Without knowing that, there's no way ANYONE can offer more than general advice.

Me, I'd say that it's probably smart to just plan on replacing everything. Who knows Why it was non-op before, what was contaminated from the failure, or if you leave something in the system will it "take out" the new parts in short order just so you have to do it all over again. But I also have the $$$ to just do the job once, might be a different decision if I were short on cash.

 

[DaMonkey]

Did the condenser hiss when you punctured it?

 

[RandyBobandy]

That’s what I’m trying to figure out, if it’s possible for me to verify my compressor is functioning, otherwise I may just end up replacing everything at once

 

[RandyBobandy]

Did the condenser hiss when you punctured it?

Yes, it hissed for quite a while

 

[DaMonkey]

Yes, it hissed for quite a while

Sounds like it holds pressure fine (before condenser puncture). Pretty good chance your compressor is the problem.

But worth checking it gets power when requested to turn on. There is a pressure switch to make sure there is pressure in the system to send power to compressor. Can check the circuit and bypass switch to check for power at harness.

Also loosen belt and spin compressor pulley, the problem may be obvious there.

When you find your problem, fix that, new condenser, drier and proper amount of oil depending on what components replaced. I borrowed vacuum pump from autozone. Add refrigerant and (or with) a uv dye and be on your way.

Oil type and amount of refrigerant is on sticker under hood. That parts easy bc you are empty.

Don’t need to replace anything unless you know it’s bad. No risk to give it a shot except for your time and some refrigerant. You can always go to a pro if it does not work out. That was my plan, and I’m still blowing coooold from fixing a leak myself.

 

[jsukey]

With it being open to the atmosphere for so long since you punctured it, I would recommend keeping it on a vacuum for several hours, if not overnight after replacing everything. Every bit of the moisture needs to be removed. The factory Denso A/C compressors aren't really known for failing. I'm sitting at 287k miles right now on the factory compressor, and it will freeze you out. It could have been something as simple as the High/Low switch failing that caused your A/C problem in the first place. I would recommend using a paperclip as a jumper where the High/Low switch is to trigger on the A/C compressor. I went through an A/C issue 2 years ago. The compressor would not kick on, so I automatically assumed that it was the compressor. After jumping the high/low switch though, the A/C would blow cold like before. Unfortunately in the 4runners, they decided against using a schrader valve on the high/low switch, so the entire system has to be evacuated in order to change the switch. I had already anticipated replacing everything in the system and had even bought a few new parts. Being that you don't know exactly what it was that failed, I would replace everything except the compressor if it passes the jumper test. I have a brand new in box drier and expansion valve if you're interested. Both are from Denso, and still in the factory boxes. Part #'s 478-0500 for the drier, and 475-0505 for the expansion valve. I'll let them go for $35 shipped for both. Just let me know!

 

[BamaDrewski]

Thank you for the write up, that is very helpful, I’m wondering though do you think it is really necessary to replace everything? I was hoping to be able to just replace the condenser and maybe some O-rings along with a flush and refill, should I replace the compressor while I’m at it? I’d probably just get a used unit from eBay

Is there any way to test the compressor to see if it’s okay?

I’m confident in my ability to replace parts, it’s the diagnosis that I’m not too experienced with

I am not sure if you have a budget in mind but working on an AC system to only "half do it" means more work sooner than later. That is why I decided to replace my entire system and for almost $600, it was worth every penny. Some of the part prices might actually be lower now. I am OCD so that's another reason I wanted to replace everything and also, the learning of the lessons in doing it really helped!

 

[Hopeless Diamond]

I am not sure if you have a budget in mind but working on an AC system to only "half do it" means more work sooner than later. That is why I decided to replace my entire system and for almost $600, it was worth every penny. Some of the part prices might actually be lower now. I am OCD so that's another reason I wanted to replace everything and also, the learning of the lessons in doing it really helped!

I read your thread and came to the same conclusion. I didn't know what was wrong with mine, other than was told it didn't work and with no belt anymore, looked like the compressor had seized. Bought and replaced pretty much everything and now have no worries. Nothing tough about it, just a lot of pieces

 

[96RedRunner]

I really didn't care for getting into Evap and expansion valve rest a piece of cake.

 

[Bad Luck]

It's entirely unnecessary to have your ac system under vacuum for more than a half hour unless you filled your ac system with water. Sounds like your compressor wasn't working, but to test the compressor you need to have a charge in the ac system. I'd replace the condenser, compressor, and receiver/drier. No point in not replacing the compressor just to find out that you need a compressor and have to pay to get the refrigerant recovered, do the repair, and then vacuumed/charge the system. That's just extra money down the drain. Your system held pressure before puncturing the condenser so that would lead me to believe your compressor has failed.

 

[BamaDrewski]

It's entirely unnecessary to have your ac system under vacuum for more than a half hour unless you filled your ac system with water. Sounds like your compressor wasn't working, but to test the compressor you need to have a charge in the ac system. I'd replace the condenser, compressor, and receiver/drier. No point in not replacing the compressor just to find out that you need a compressor and have to pay to get the refrigerant recovered, do the repair, and then vacuumed/charge the system. That's just extra money down the drain. Your system held pressure before puncturing the condenser so that would lead me to believe your compressor has failed.

The 30 minute vacuum test was recommended in the Toyota Service Manual so I think there is a reason for it.....especially after all new components are installed.....IMO