1st Gen A/C System Replacement How-To (Seized Compressor)

Wolfgang, I'm glad you decided to take on the job!

Did you happen to use already UV dyed PAG46 oil when you replaced your dryer? If so, now it's just a matter of taking a UV light (blacklight) and looking all over your system for a leak. Be sure to check the drain from the evaporator housing that comes through the firewall. Or twist up a paper towel and thread it in there and pull it out to see if you may have a leak at some point in the evaporator housing.

 

YES SIR PAG46 oil with UV dye. problem is when i disconnected the high pressure line from my gauge set UV dye and PAG46 oil got everywhere, exploded all over me (haha). So i am going to need to clean the engine bay and try again before i can find the leak.

 

Yea that'll happen; make sure you're wearing some glasses when you do that. There should some dye left in the system I'd imagine. It seems like a lot shoots out of that high pressure line, but really it's not that much its just under a good amount of pressure so you get a sizable spray.

 

UPDATE:

First few warm days of the year the system was blowing cold working great. But, I noticed some PAG oil around the fitting for the Low Pressure line right after the firewall. I traced it back to the black plastic clamp that I reused after the fix. I just poked it with my finger and the clamp failed, line burst off, and my system discharged.

Lesson learned: This clamp needs to either be removed with the proper 2 pronged removal tool ($20) or replaced with a new OEM unit($3.50). I took it off with a small screwdriver and it damaged the clamp just enough for a few MM of play which was enough to cause it to fail.


I'm just going to guess I lost about 3oz of PAG oil (any other guesses?) and so I'll just add that into the compressor then vacuum and recharge the system.

 

Subbing for future.

My a/c compressor intermediately seized causing smoke I guess from the belt burning. I plan on replacing it when I can but I think I will just remove the belt for the time being. Since it is not fully seized do you think I will need to go through all of this or just do a new compressor?

 

Well, if it's only seizing intermittently that means the compressor hasn't completely grenaded yet so I'd imagine you would be fine with just a new compressor; worst case scenario.

That being said, with the problem you describe I'm thinking a new compressor might not even be necessary. It sounds more like a problem with the A/C Clutch. The part that the belt is on on the front of the compressor is a pretty simple clutch and I've seen them go bad well before the compressor itself. New clutch kits can be had for around $50, maybe less. You wouldn't even have to discharge the system.

With the engine off, pull on that clutch and if there's any lateral movement (front to back) I think you've found your problem. Let me know how it goes.

Also, disconnect that belt for now (or just cut it off and replace with new once fixed) to avoid potentially making the problem worse.

 

Don't worry about that bolt, worst case you might have some rattling without it.

I used a number of socket extensions and joints to get a good angle on it; definitely frustrating though.

 

Going through the process now... and it turns out that the connection in the low pressure line, just forward of the firewall, is a BITCH to get loose.... Feels almost like I'm cutting new threads, and progress (movement in the loosen direction) is really tough, but the nut turns in the tighten direction fairly easy, at least to the point where I think I started.

Are those connections normally that difficult to disconnect?

Forgot to post the first comment, and got through that ordeal. And if in fact reassembly is just dis-assembly in reverse, I'm sure looking forward to it so I can go sane....

 

no, it should be like any other fitting.

the aluminum may have corrosion on it so screw it in to the loose spot and hit it with some wd40 and let it soak in a little bit then unscrew till it just starts to get resistance, then go two turns out and back in one turn and then go two turns out and back in one turn and continue that process until its no longer hard to turn or its all the way off. its just like you do with any stuck nut or bolt on the engine.

if you over tighten the nut it can deform on you and it could be this causing issues or the threads may be coming off from the nut or the fitting. whichever side the threads have rounded off on (sharp thread edges are gone) will most likely need to be replaced unless you are very very lucky.

if it feels like you are cutting new threads it is often because you are or you are peeling off the existing threads sharp edges.

 

Hi Karl--

Thanks for the response. You were right: I think that the difficulty I had getting that coupling disconnected was related to the aluminum deforming as I was trying to wrench it off. Some blaster loosened it enough to come off with little further damage, and as it turned out I must have been very very lucky, because it went back together afterward well enough to have held pressure since that day, and it's still blowing quite cold. That evening, after I got everything put back together and charged with 134a, the outlet temp was 43 degrees on an 84 degree night, so I was pretty pleased with the results.

Also, as the OP mentioned (I think), dealing with the evaporator assembly was the biggest difficulty in the repair for me. The upper left 10mm bolt/screw that holds the assembly in place was a pain to access. It would have been much easier had I had some ratcheting flex-head wrenches, which I promptly went out and got in the next few days. I picked up a set at Harbor Freight which seems like it'll be reliable, and was reasonably priced, item 60592. No intention here to place an ad for those guys, only to help if anyone else is contemplating this repair.

Here's the link in case it helps anyone:

 

glad you got it all sorted out, its too damn hot now to be without a/c

 

Looking for a bit of advice. The local shop is telling me that to remove the AC condenser on a 99 Tacoma xtra cab sr5 manual transmission 3.4 I need to remove the radiator. Looks like I can just sneak it out the front...local mechanic said I will have a 'big problem' with the lines. Is he correct or exaggerating? thx all.

 

I realize this thread is several years old but I am about to tackle this job on my 04 single cab this weekend, and have a question about the oil in the system and the vacuum pump.
1.) when you are putting PAG oil into the evaporator and condenser, does it matter which end you pour/ squeeze it into (do you put it in the inlet or outlet side)? I know the article states to put the oil in the outlet of the receiver/dryer, but didn't say anything about the evaporator or condenser.
2.) when you say "make sure the vacuum pump has the correct amount of oil in it" do you mean internal pump oil for the pump? or do you have to put PAG oil in the vacuum to circulate through the system? Also, I was wondering how the oil that you place in your A/C components doesn't get sucked out during the evacuation process using the Vacuum pump?

3.) lastly, does anyone have a part number, or know the name of this little black clamp? Is it the one in the write up pictures on the small line just before it goes into the fire wall?

 

Hey Clemson,

You're right, definitely an old thread but I do still like to try and check every few months to see if there's questions I might be able to answer about this particular job and luckily I just happened to catch yours.

1) Good question, I remember having this same thought. Unless your Evaporator and/or Condenser came with instructions otherwise (which I don't imagine they would), best practice would be to put the PAG oil in the inlet side of those components so that when you first begin to put a charge on the system with refrigerant the oil is pushed into the component.

2) That comment about oil in the Vacuum pump refers to the oil that lubricates the pump itself. If you bought a new pump for the job it will come without lubricant in it and you will need to fill it up. Also after running one of these pumps for an hour or so they tend to use quite a bit of oil (mine did at least), so make sure levels within the pump are topped off prior to operation. It's only to protect the health of the actual pump, there's no impact on the A/C system.

2a) The PAG oil that is put into the system is too viscous/heavy to be pulled out by these pumps. The only time this oil would be pulled from the system is when the system is charged (full of refrigerant) and then released. This would occur either when a shop recovers refrigerant or if there was a sudden break in the lines. Its the huge sudden pressure differential and the ability of the liquid refrigerant to carry the oil out that would cause the oil to leave the system only in those cases.

3) I don't have a part # for the clamp unfortunately. I remember I found it off of Toyotapartsvillage or something like that then went to the dealer to buy one. It's was very inexpensive, under $5. Learn from my mistake and definitely buy a new one.

Let me know if any other issues pop up along the way, I'm sure other people have the same questions.
Thanks

 

Hi Ed,

At least on the 2.7L the Condenser and all associated lines were mounted completely independently of the radiator and it's hoses. Never had to touch the radiator and the Condenser and lines came right off.

I don't have the experience with the 3.4L to say for sure it is the same deal, but I imagine it should be. If you think you can sneak the lines out I believe you. Just be careful, they are pretty fragile.

Good Luck

 

Geodude,
thanks for replying quickly and clearing up all of my questions. For future reference for other members that will attempt to do this job, the part number for the clamp on the low pressure line close to the firewall is 88718-02170 PIPE, CLAMP.

 

All the parts have finally come in to do this job, now I'm just waiting on a free weekend to get it all installed. I'm going to have a local mechanic I trust pull the vacuum and recharge the system. I was talking to him yesterday after I had some work done on my other truck. And, he mentioned that instead of adding PAG oil manually to each component as specified in the OP's instructions, that he has a machine that will inject oil into the system at the right viscosity and right quantity for my truck before it charges the system with refrigerant. He says this is how they do all the vehicles they work on and it wouldn't cost anymore to add the oil than the standard vacuum and charge fee would. It would save me time of having to measure out oil and put in each component, but I don't mind doing that if it's going to be better in the long run for my system. Anyone have any experience with this, or see any cons about having the machine add the oil.

 

I used your write up this past weekend to rebuild my AC system. I did have a shop evacuate it and recharge though. I also replaced the timing belt and all the stuff that goes along with it while I was in there.

 

This is a great write up.

Just used this write up to replace the A/C condenser pipes that go through the firewall, one had a link.
The minimum is back together now so I will be taking it to a shop to have them charge the system.
Do I need to tell them anything specific, or just to evacuate and recharge?

Thanks in Advance.
Carlos

 

Trying to figure out what he means by pry off the clamp on the high side to remove the evaporator....