DIY Complete AC Replacement on 2000 T4R Limited

awesome thread. one more of the things on my list to do to my 4runner. When I got it it had been hit on the front passenger side and the condenser was damaged so the AC didn't work. I took the compressor out shortly after I got the 4runner, kept all the tubing and hope to rebuild at some point.
 
Meetball: Are you doing a complete AC rebuild as well?

No. This started as just a replacement of the evaporator core, expansion valve and the tube assembly....til now.

Need help.

Replaced the above mentioned parts with either rockauto.com or dealer parts. Reassembled, and took to have recharged. 29mm of vacuum held for an hour, recharged, and blew great (according to the words of the shop, and I trust them). Said they put 1.6 pounds in. An hour later, my wife and I go to pick it up, and there's an issue. The truck wanted to idle around 500 rpm, and the compressor started kicking on/off continuously. It didn't blow cold, and nothing in the dryer sight glass. Leak, right? I could rev it up some, and the engine would smooth out, the a/c fan would speed up, compressor cycled on (and stayed on until I let go of the throttle), and I could see freon in the site glass. Let off the throttle, and it would go back to the same crap. Shop and I agree that there must be a leak.

Get this, they pulled 1.6 pounds back off of it. Had them pull the system back down so I could look to see what was wrong, and there was no leak.

SO, WHAT THE HELL IS GOING ON?:wacko:

Any pointers in a reasonable direction will be greatly appreciated.

(if this is a hijack, let me know and I'll post a new thread)
 
No. This started as just a replacement of the evaporator core, expansion valve and the tube assembly....til now.

Need help.

Replaced the above mentioned parts with either rockauto.com or dealer parts. Reassembled, and took to have recharged. 29mm of vacuum held for an hour, recharged, and blew great (according to the words of the shop, and I trust them). Said they put 1.6 pounds in. An hour later, my wife and I go to pick it up, and there's an issue. The truck wanted to idle around 500 rpm, and the compressor started kicking on/off continuously. It didn't blow cold, and nothing in the dryer sight glass. Leak, right? I could rev it up some, and the engine would smooth out, the a/c fan would speed up, compressor cycled on (and stayed on until I let go of the throttle), and I could see freon in the site glass. Let off the throttle, and it would go back to the same crap. Shop and I agree that there must be a leak.

Get this, they pulled 1.6 pounds back off of it. Had them pull the system back down so I could look to see what was wrong, and there was no leak.

SO, WHAT THE HELL IS GOING ON?:wacko:

Any pointers in a reasonable direction will be greatly appreciated.

(if this is a hijack, let me know and I'll post a new thread)

If there was a leak at the start, then the vacuum should not have held. Did you replace the major components with Denso or aftermarket from places like RockAuto? I would definitely swap out the AC relay under hood. If I remember correctly, it is one of larger relays in the fuse box. Did you replace the pressure switch?
 
If there was a leak at the start, then the vacuum should not have held. Did you replace the major components with Denso or aftermarket from places like RockAuto? I would definitely swap out the AC relay under hood. If I remember correctly, it is one of larger relays in the fuse box. Did you replace the pressure switch?

One other thing: Did you replace the expansion valve? I suspect it is either the low pressure switch or the expansion valve but those are just guesses.....I think the system only takes around 20 ounces of R134A and I am wondering if that equates to the 1.6LBS you mentioned....
 
If there was a leak at the start, then the vacuum should not have held. Did you replace the major components with Denso or aftermarket from places like RockAuto? I would definitely swap out the AC relay under hood. If I remember correctly, it is one of larger relays in the fuse box. Did you replace the pressure switch?

The evap and valve were Four Seasons brand from rockauto, and the tube assembly from Toyota. I did lube all seals with PAG oil. No replacement of any switches or relays. Only the system that is under the dash.

Where is the high pressure switch, and is there a chance that the system could have been overcharged?
 
The evap and valve were Four Seasons brand from rockauto, and the tube assembly from Toyota. I did lube all seals with PAG oil. No replacement of any switches or relays. Only the system that is under the dash.

Where is the high pressure switch, and is there a chance that the system could have been overcharged?

I understand our systems only have a R134A capacity of 20 ounces which equals 1.25lbs. if the guys who worked on your system put in 1.6lbs, then it is probably over-charged. I would strongly recommend checking the expansion valve and pressure switch. Sounds like there is no leak as you mentioned they got the same amount of R134A out as they put in. Also, if there was a leak, as I mentioned before, the vacuum pull would have failed.

I did a 30 minute vacuum pull on my system with a SnapOn automatic machine that pulled vacuum and also metered in the R134A per the specs of the T4R. Also, when you got the new compressor, did you prime the compressor with PAG46?
 
I understand our systems only have a R134A capacity of 20 ounces which equals 1.25lbs. if the guys who worked on your system put in 1.6lbs, then it is probably over-charged. I would strongly recommend checking the expansion valve and pressure switch. Sounds like there is no leak as you mentioned they got the same amount of R134A out as they put in. Also, if there was a leak, as I mentioned before, the vacuum pull would have failed.

I did a 30 minute vacuum pull on my system with a SnapOn automatic machine that pulled vacuum and also metered in the R134A per the specs of the T4R. Also, when you got the new compressor, did you prime the compressor with PAG46?

Make sure everything is plugged in. How did the 4runner behave as the shop was filling it?

Did not install a new compressor. I am heavily considering it right now, though. And I understood that the 2000 model held 23 oz of freon and 7 oz of PAG.

Everything was plugged in because the shop said it worked fine and acted normal during the whole process. Only developed an issue after it sat for about an hour before being restarted.
 
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Did not install a new compressor. I am heavily considering it right now, though. And I understood that the 2000 model held 23 oz of freon and 7 oz of PAG.

Everything was plugged in because the shop said it worked fine and acted normal during the whole process. Only developed an issue after it sat for about an hour before being restarted.

Just an update to this for anyone who might experience similar problems.

I had a lead that originated from the gap between the tube assembly and core. There was a very fine tolerance on the high pressure switch and combine that with the tolerances on the shops equipment, the system was just over charged.
 
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Glad you got it fixed. Sounds like the shop overcharged it (1.6lbs) from the start. The specs call for 20ounces or 1.25lbs approximately.

With respect to the leak, was there an O-ring on the tube connection that you found leaking?
 
Glad you got it fixed. Sounds like the shop overcharged it (1.6lbs) from the start. The specs call for 20ounces or 1.25lbs approximately.

With respect to the leak, was there an O-ring on the tube connection that you found leaking?

Yeah that was my immediate thought after seeing 1.6lbs was put in! That's way too much, and will cause the compressor to cycle over and over again because the pressure is building too quickly. FWIW most newer cars are taking less than 1lb of R134a.
 
I'm about to try this deal

for anybody who comes along and is wondering about the capacity this seems to match what is discussed in this thread.

Toyota Refrigerant and oil capacity charts || TechChoice Parts

and a capture for when it gets moved or broken

<a href="https://imgur.com/unjKq3D"><img src="https://i.imgur.com/unjKq3D.png" title="source: imgur.com" /></a>

the only reason I put this one out is because the FSM is confusing

<a href="https://imgur.com/zrvAD9m"><img src="https://i.imgur.com/zrvAD9ml.png" title="source: imgur.com" /></a>
 
Specified amount: 650 ± 50 g (22.92 ± 1.76 oz.), pg AC-58 of FSM, equals 21.16-24.68 oz operating range.
I used two 12 oz cans works great, I figure 23-24 oz is what got put in after purging guage hose.
The 25 oz is higher than specified range, a hot day in stop n go traffic might cause high head pressure issues or less than ideal efficiency.
 
Specified amount: 650 ± 50 g (22.92 ± 1.76 oz.), pg AC-58 of FSM, equals 21.16-24.68 oz operating range.
I used two 12 oz cans works great, I figure 23-24 oz is what got put in after purging guage hose.
The 25 oz is higher than specified range, a hot day in stop n go traffic might cause high head pressure issues or less than ideal efficiency.

I think I understand the table I posted in the FSM after reading a bunch of stuff. the table I posted indicates the the amount you should put into those components when replacing them. I was confused like normal.

but yes for sure after reading the entire AC section it does spell it out very clearly.

I'm going to rip into mine tonight and maybe... just maybe I will have AC back here in a day or 2.
 
I was confused like normal.... just maybe I will have AC back here in a day or 2.

Confused, Lol, we all been there.

The FSM is good for weeding out the BS of the net, though it doesn't tell you the tricks of the trade.
I would rather charge an empty system over topping one off, less complicated.
It helps having your own Vac pump, guages, dye cartridge for putting in oil and dye.
Good Luck getting yours going.
 
Confused, Lol, we all been there.

The FSM is good for weeding out the BS of the net, though it doesn't tell you the tricks of the trade.
I would rather charge an empty system over topping one off, less complicated.
It helps having your own Vac pump, guages, dye cartridge for putting in oil and dye.
Good Luck getting yours going.

I have it all out just waiting on the evap core part, have everything else waiting inside the house.

I was not going to do the evap core but I'm glad I did... maybe took me 4 hours to get it all out. but I'm pretty slow and also clean the pieces and parts I take apart so they will be ready to go once I get at it again. it's like +1 million deg outside today.


<a href="https://imgur.com/vdCdBAR"><img src="https://i.imgur.com/vdCdBARl.jpg" title="source: imgur.com" /></a>
 
I have it all out just waiting on the evap core part, have everything else waiting inside the house. it's like +1 million deg outside today...

Looks like my pile back in 2012, mine was all junk because of drier cartridge breaking apart. Lol, it's only 999,999 deg on third cost.
 
I have been working so much, I have not had much of a chance to check in to this thread.

One suggestion; if you are getting a new Denso compressor, empty the oil out of it when it arrives and refill with leak dye oil to the specifications. That way, you have the leak dye in your system already and it makes it easy to find leaks. Since redoing all of my system (which made me write this DIY in the first place) I have had no leaks at all and the system still cools. It now cools between 34 and 36 degrees on a hot summer day in Alabama.....good luck and be patient and it will pay off!
 
Thanks for this write up. I just got a new to me 4runner and the A/C isn't working. Think i'll try recharging it and if that doesn't work i'm just going to replace everything because the price isn't too bad.
 

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