AdventureTaco - turbodb's build and adventures

One thing I'd probably do is lighten the dark areas of the truck. Only so my eye didn't sink in the fore and mid ground.

 

See, this is entirely unrealistic, the sky is blue Dan... even a kindergartner could tell you that. Thankfully I was here to help...

 

Always looking forward...

 

If At First You Don't Succeed - Fixing the A/C, Again
Let's see, how did this start last time. Ahh, right...

Well, I replaced the A/C evap core and things worked well for all of one week. While that sounds bad - and I guess ultimately it is - we counted our blessings that the end of the week was the same day we finished running the Nevada Backcountry Discovery Route (NVBDR) for the first time. With days over 100°F, we'd have suffered immensely had the A/C not held out as long as it did!

At any rate, with all the components in the cab of the truck replaced, I turned my sights on the next culprit - the A/C Compressor. Why the compressor? Well, when I'd charged the A/C system, the low pressure on the manifold acheived the correct pressures - around 32psi - according to the Factory Service Manual (FSM), but the high pressure side of the system never got quite as high as the FSM suggested it should - it got to ~125psi instead of 150-200psi. A bit of research indicated that this could be due to the compressor starting to go, and so that's where I was going to start.

Gathering Parts
Replacing the A/C compressor means I needed - obviously - need a new compressor. I had a couple reasonable options in this space - OEM or Denso:

• Toyota OEM - I could have gone Toyota-OEM-sourced here, but it's pricey. Personally, I recommend against it because the Denso option is a lot better. The OEM compressor does not come with a clutch, so you'll need to re-use your old one or buy a new one
  • Toyota OEM A/C Compressor w/o Clutch (88320-35550-84)
  • Toyota OEM A/C Compressor Clutch (88410-35340)
• Denso A/C Compressor w/Clutch (471-1223) - Denso makes the Toyota OEM A/C compressor for Toyota, so this one is identical except for the box. Plus, it comes with a new clutch! Save a few hundred dollars and be just as happy? Yes please! This is the part I recommend.
• DEX/MERC ATF - 1qt - I needed this to refill the power steering pump after removing it, since some of the fluid in the reservoir was going to be lost in the process.

I also picked up a few other things for this job. I already had a kit with all of the o-rings I was going to run into from the last time I worked on the A/C system, and as I mentioned then, it's good practice to replace your Receiver/Drier any time you replace a major component of your A/C system. So, then, the following parts:

• A/C Receiver Drier (88471-34010) - I picked up yet another one of these.
• Santech MT2580 A/C System O-Ring and Gasket Kit - I already had this kit from my first attempt, and it has plenty of o-rings in it.
• A/C PAG46 Oil - 8oz - this oil is used to lubricate various parts of the system, which I already had on hand from last time.
• 10ml (10cc) syringe - used to measure the right amount of PAG46 oil into the system; again, already on hand.

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I also - of course - would need to charge the system again, but I already had everything for that, and I've covered how to do that over here, so I won't list it all again: Charging the A/C System on a 1st Gen Tacoma (or 3rd Gen 4Runner).

Doing the Job
What follows here is the saga of my specific repair. If you're interested in the step-by-step, with lots of photos version of this job, check out

Replacing the A/C Compressor on a 5VZFE
(Tacoma, Tundra, 4Runner)​

This time, instead of starting with the Receiver/Drier, I got started with something that's not a part of the A/C system at all. Two somethings, actually! First, I removed the air intake box, so I'd have a bit of room to work. This is just three bolts, a couple hose clamps, and unplugging the MAF, so it went reasonably quickly.

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And with the air intake box removed, the next order of business was to remove the Power Steering Pump. See, on a 5VZFE engine, the A/C compressor has to come out the top of the engine compartment. And, the power steering pump is in the way of that being an easy process.

I loosened all the requisite nuts and tensioning bolts to remove the belt that drives the power steering pump, and then disconnected the hoses from the pump. As one does, I spilled power steering fluid - actually automatic transmission fluid (ATF) - everywhere during this process.

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That of course meant that I spent nearly as long cleaning up my mess as I'd spent on the pump removal itself. Fun times. Good practice, I guess.

So, with the power steering pump removed, I repeated a similar process with the A/C compressor - except that it was a lot cleaner, since the A/C system was completely discharged at this point, with nothing to leak out of the lines as I removed them from the compressor.

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Success!​

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Looks similar, I probably muddled my way through getting the right part.​

Transferring the top plate from the old compressor to the new, draining the oil that shipped in the compressor and refilling it with 125cc of PAG46 oil, and replacing all the gaskets and o-rings was the next order of business. All that went smoothly and before long I was ready to put everything back together.

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For anyone who's ever had a Toyota FSM, we all know that putting things together is significantly simpler - at least to write about - than removal. It's simply the reverse of removal.

This time though, everything was reasonably straight forward, and in an hour or so, all the belts were tightened, and I was pulling a vacuum on the system and hoping that everything checked out.

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I couldn't believe it after the last saga I had with holding vacuum, but this time it held the very first time. Celebrate? Why yes, thank you!

So, with the help of @mrs.turbodb in the cab - keeping the revs at 1500RPM - I proceeded with Charging the A/C System. With previous experience this seemed to go well enough, and the pressures on the manifold climbed into their FSM specified ranges as I filled the system with the specified amount of R134a - more success!

And with that, as a "glass-half-full" kind of guy, I probably should have considered themselves done and happy. But, I'm not - because I'm not sure the saga is over. Here's why. Three reasons:

1. The A/C still isn't blowing as cold as I'd expect. It's cool, for sure - blowing around 58-60°F on an 85°F day - but my 3d gen 4Runner blows air in the 52-53°F range on the same day.
2. The sight glass in the A/C Receiver/Drier isn't acting quite as I'd expect. During normal operation, it appears reasonably clear - well, yellow due to the UV dye that's in the system - which is correct. However, when I shut down the engine, the FSM states that it should bubble momentarily and then go clear again. As far as I can tell, it does not - it stays yellow. The FSM suggests that this means there's too much refrigerant, but I'm quite certain the correct amount is in the system, and the pressures on the manifold are correct. I am confused.
3. When I went out to check on the system a couple days later, and I unscrewed the valve stem cover to the high pressure access port, I could swear I heard the smallest amount of pressure leak out. I filled the port with some soapy water to look for bubbles and there were none, but I'm still a bit on edge about hearing pressure there. A(nother) leak?

So, A/C experts - internet or otherwise - with those three concerns I still have - what do you think? Let me know because right now, I'm just in wait-and-see mode to see if this thing is fixed. And I don't love wait-and-see!

 

Sounds overcharged, just a bit. AC units over perform slightly undercharged and under perform overcharged. The sticker on the core support is close enough, but it gonna vary a bit. After you get close to the baseline, I charge with a temp probe in the vent and go slowly on the charge until the gauge just starts to come up slightly from the coldest output it recorded.

 

If you didn't fill the system by weight... you probably do not have the right amount in the system.
Also, if you didn't replace the O-rings on any re-used connection, you may have a slow leak.

@Speedytech7 has a good method, I've never tried tuning output this way, but it makes sense.

 

1. I'd check your pressures again. Sounds like maybe you don't have enough coolant.
2. idk. But if you have dye in the system, it will not turn clear.
4. Find a black light and yellow glasses. Check the valve for leaks.

 

That's an interesting way to go about it. I felt like it might have been slightly overcharged...but with a bit too much oil. I did all this about a month ago, and I bled out a bit of mix, and things seem to be better. Hopefully it's no longer leaking either; only time will tell I guess. I never found a leak anywhere, even with plenty UV of dye and a black light.

TL;DR, ehh? All the o-rings were replaced and oiled - well, all of them that I accessed. There are a few - at the condenser connections - that I haven't touched, as that's the only component I haven't replaced.

I did fill it by weight, and also by pressure. Pressure is actually more important than weight - as I understand it - since I wasn't starting "from scratch" with all new components, and so there can be some residue in the condenser for instance. I'm right in the correct ranges on both the high and low side..

#2 - I'm not looking for it to turn clear, but my understanding from the FSM is that it should "bubble" for a second after shutting off; I don't see that "bubble" happen.
#4 - I've used a dye and black light since this all started . So did the dealer. We've never been able to find the leak, though there quite obviously was (hopefully not "is") one.

 

One thing I did fairly recently was to power wash the cooler, radiator, and condenser. That made a bit of difference as there was a fair bit of dirt and debris on all three. Especially on the past few days of 100+ degree days.

 

Remember that your pressures are all entirely ambient temperature affected. So I doubt it bled anything. The hotter it is out the higher the pressures run when the system is in use

 

What do you mean you doubt it bled anything? I bled it into a container and got probably 7cc of oil/dye out.

 

Ah okay, I thought you meant refrigerant charge was bled.

 

I maintain that the pressurized vehicle for the oil and dye was magic carpet. All the pressures are still in the correct ranges, so I'm hoping the slightly lower volume - essentially what you were talking about - will solve the issue. Fingers crossed.

 

Don’t modern refrigerants have a sealant in them?

 

Only if they say they do. Those are usually the ones that come in the can with the hose attached. Advertised as a problem solver type product

 

Maybe I saw it on one of those cans. Which probably means you'll be buying parts later on anyway

 

Yeah, I made sure to get just straight refrigerant. Amazing how much the cans with "problem solvers" (dye, sealant, oil, etc.) cost. Like 3-4x the price. I guess if you don't have the manifold, or just want a quick fix...

Zane - didn't you say that a can of the sealant stuff worked for you at some point?

 

Yeah, it's actually one of the few things I totally recommend, won't hurt anything in the AC system at all and it has the potential to seal up lots of little shit, which on vehicles like ours that get their shit rattled apart is a big boon. I used a can of sealing refrigerant on my truck as a first try before I broke out the tools. It's cheaper than even doing the diagnostics first haha. Just so happens it took and it works great still and the pressure always checks out in the right ballpark for the given outside temp.

 

Speaking of shit rattled apart, while I was washing the condenser, I noticed the whole thing has a bow in it...10 years of use I guess.

 

Our condensers are supported extremely poorly and in 01 they redesigned the lines that go to the drier to make them less prone to leaking... The AC system is a bit of an after thought I get the feeling.