Hello T4R homies. I'm gearing up to replace virtually the entire A/C system. When I bought the vehicle, it worked great. Turns out the (highly dishonest) dealer overcharged the system just to get it off the lot (damn him). Because the Runner came from up north, it has a lot of rust and corrosion on the underside of the engine.

In short, the A/C system leaks like a sieve. Virtually every joint and gasket has some sort of leak. The biggest leak is around the end of the compressor where the pulleys are. I used some dye to find all the leaks and they're everywhere, so I'm going to do a complete replacement of the A/C system. My question is has anyone done this? And if so do you have any pointers or tips to do this? I have a good working knowledge of A/C systems and a vaccuum, gauges, etc. Should I replace all hard lines too? If so , where can I get them? What components are needed to do a complete replacement?

I will try and post pictures when I get off work today.

Get all the aluminum lines (from a yard) and all the other parts filter condenser O-rings (New). Find a good compressor. I think it is 17 (the number embossed to the side of the compressor) the 15 is for cars like corolla.

If you plan to buy a used compressor (which is not bad) check it out. Close the high side output by thumb and just turn the clutch about 45 degrees ONCE in either direction. If you feel a very HIGH pressure at your thumb, the compressor is good. I've dealt with many denso compressors and nearly all I find in salvage trucks/cars are good.

You have to add compressor oil into the compressor. Connect the ac lines, use O-rings and don't use any lubricant on O-rings.

Vacuum the system, check the vacuum gauge for about 1 hours to see any leaks, then add gas.

I have always used PAG-Oil (AC compressor oil) to lube the O-rings. Everywhere I have read says to.

Here are the pics of the freon leak found using dye.

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I believe fellow member @BamaDrewski has replaced the whole system, maybe excluding the hard lines. PM him for some guidance.

A short ratcheting 14mm wrench makes short work of removing the compressor bracket bolts.

Good luck.

I bet you could just replace all those O-rings and get yourself a tight system, unless you find real physical damage. You might even discover some bozo PO used regular black O-rings instead of PAG resistant green ones. Might get away with just a new dryer.

^^^ Yeah, get new O-rings.

Update about the O-rings and oil:

The O-rings that gets switched are the one's I don't apply oil. The ones that slides into another tube gets a tiny film on the sliding surface.

When I do the manifold on the ac compressor I never use oil on the gasket and the result is always a success.
Just what works for me.

Man, the AC condenser aluminum fins are missing at the bottom!

I essentially rebuilt the ENTIRE system with DENSO parts and it was not a bad job at all. I have all the part numbers and the costs to do it when I did it a couple/three years ago. Let me know if you need any input and I will be happy to help....

Here is a brief overview of parts and costs when I did it:

AC Compressor with Clutch (88310-35770-84) DENSO
Condenser (477-0518) DENSO
Evaporator Core (88501-35050) DENSO
Expansion Valve (88515-22240) DENSO
Pressure Switch (88645-04040) Santech
Receiver/Drier (88471-34010) DENSO
O-Ring Kit (FOUR SEASONS)
Controller - Blower Motor on Evaporator (87165-33010)
AC Suction Hose (887123-5540)
AC Discharge Hose (887113-5490)
AC Liquid Line (887163-5390)
AC Condenser (477-0518)
AC Pressure Switch (88645-04040)
Magnetic Clutch Relay (90987-02028)


Also bought some "Aerosol AC Pro Flush" to clean the lines before reassembling with new parts. I spent about $600 and have a whole new system which has run flawlessly ever since. Let me know if I can help...

NOTE: I priced everything out and compared prices across 6-8 different suppliers and found AMAZON was the most competitive on 95% of everything I bought and it was all DENSO will a few small exceptions like the O-rings, flush, etc.

You don't want to use PAG oil on the o-rings, it makes them sticky. Use either mineral oil or preferably silicone o-ring lube as it makes them slippery so they don't tear as you tighten the fittings. I spent 10+ years doing automotive A/C so I have a pretty good idea about what works and doesn't.

Well, Toyota disagrees with you. See par. 3 in attached link:

http://tacoma.site40.net/4Runner_96-.../rece/remo.pdf

[My bold added]

It's always worked for me. I have never had one tear on installation if they were the correct size.

That said, I think mineral oil, PAG oil and Silicone lube will all work fine. The green O-rings are supposed to withstand all three.

I know it's been a while, but just wanted to update by saying that I've got the compressor, condenser, dryer, and evaporator on order. I'm going to try and re-use all the lines if possible. I'll keep this thread updated as I go along. Thanks for the input everyone, it turned out to be very helpful - especially @BamaDrewski 's parts list - I may try to do a flush just to clear everything out as well.

Unless there is a major problem with either the condenser or the evaporator, I'd skip replacing them unless you want to shell out the $$$. Like Durk said, just replace the O rings at the connectors and lubricate accordingly. I would DEFINITELY replace the expansion valve though and drier.

A cleaning of the fins of the condenser would help.

Keep us posted.

I'd agree with evaporator, expansion valve, compressor, drier, and condenser replacement. You don't know what debris is floating around and also the fins being damaged reducing efficiency.
Flushing hard lines should be fine. Messy, but works well. I've only had to replace lines if the fitting threads seize or strip.

Also, I use Vaseline as o-ring lube, when it's a slide fit. Worked ok for me for years now.

Good luck

UPDATE:

I finally was able to start on the A/C system repair. It took my Dad and I pretty much a whole day to replace the compressor, the drier, and the condenser. @BamaDrewski I did not replace all the hoses since they seemed to be in good shape. We used green PAG O-rings except for the gasket on the compressor manifold because the one we had didn't seem to fit just right. Is this normal? The curves on the gasket seemed too thick for the slots in the compressor? We used the black one that came on the cover plate (that covered the manifold opening on the compressor). I wish I'd had my wits about me to take more pics. Needless to say, after hooking up the vacuum pump, we still have a leak...

and on top of that I broke the carriage and bolt for the compressor idler pulley... gotta love rusty 4runners... I already have that on order though.

My questions are: should I continue using the black gasket or switch to the green one that came with the compressor? And should we be concerned about the evaporator core and expansion valve? Are there gaskets around those as well? I'm not familiar at all with the under-dash part of this system.

Also, @nissanh check out the condenser...

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