Builds 1991 FJ75 moving to America (3 Viewers)

[Honger]

Glad to have you in the club and happy to see you're reppin!

Of course! Once I get the AC working this'll be making its way all over AZ and to Copper State meetings.

 

[Honger]

Managed to actually get the SST required for tuning my carb... 09243-00020.
It's a discontinued part, but managed to get it from some sort of parts shop in Thailand.

 

[Honger]

Also, spent a solid 40 minutes outside with the truck this evening drawing up a schematic for the overall AC system. The dual AC system worked really well before we had to drain the R12 back in Abu Dhabi for replacing the radiator support. I'm working on converting to R134a... but I needed to know what I was getting myself into.

Two condensers, two evaporators, two expansion valves, an electric fan on one of the condensers, a T in both the high and low pressure lines, and an aftermarket Sanden compressor on a fab'd up compressor bracket.

It got even more fun as I mapped out the system...

I numbered each hose and each pipe with a sharpie.

The high-pressure side has an interesting solenoid valve just after the T, heading toward the rear AC.

Presumably when the rear AC is off, that valve is closed.

Next step is disassembly, flushing of each component, and then reassembly with PAG oil and finally a recharge.

 

[Honger]

AC work has been ongoing. Using various references from the forum, especially this thread by @4Cruisers, I put together the following plan of attack:

1. Map out the existing system.
2. Disassemble the components and flush them.
3. Empty the compressor of as much of the old oil as possible.
4. Install new expansion valves and a new drier bottle.
5. Re-assemble components with new o-rings/tefflon tape as applicable.
6. Change ports on compressor to R134A compatible.
7. Fill the compressor with the appropriate amount of new oil (PAG 100).
8. Draw a vacuum (I bought a Mastercool 6CFM unit for this).
9. Hold vacuum and then recharge with R134A (I also bought a Mastercool manifold gauge set).

Getting started then... I began dismantling hoses.

Everything was covered in a gunky film of fesh-fesh...

So I've been cleaning most of the components as I go.

And then flushing using this handy apparatus. You fill the reservoir with AC flush solvent and then connect to your air compressor. The air forces the solvent in one end and out the other depending on where you inject and where you've opened the lines.

In this case I cleaned out the front condenser plus a long hose and it built up enough surcharge while flowing through that it exited rather explosively.

It does a great job of cleaning out the lines. You can't run this through the compressor, the drier bottle, or the expansion valves. So say the instructions as well as numerous references I found.

For smaller components I blew through smaller quantities of solvent.

 

[Honger]

Tonight my boy and I started pulling the AC evaporator out so I can change out the expansion valve. I've got a new Denso unit to go in. This didn't turn out to be quite the ordeal I expected.

First of all, we removed the front passenger seat as per @2fpower's advice. It was good advice.

Then we pulled out the glovebox insert and remove the glovebox door. You're left with this view.

There are three modules there... on the left a plenum that distributes air and can house a heater core (if your vehicle has one). In the middle the AC evaporated housing. On the right the blower motor and fresh/recirculate selection flap.

With a few bolts and screw removed and a couple plugs unplugged the AC unit actually comes out by pulling down and away from the other modules...

Obviously you'll want to have disconnected the ac lines on the other side of the firewall in the engine bay before pulling the unit.

After that you can actually easily pull the blower out as well.

I was expecting to find a second project on top of the AC project once I started going this far in. I was not disappointed. The AC evaporator assembly as well as the blower motor assembly are filthy! So a deep cleaning is planned.

The expansion valve and pressure switch are both neatly contained within the housing as well. I'm fairly impressed with the modular way this system goes together. I'll have to split the AC housing open to both clean and replace the expansion valve.

 

[Honger]

Pro tip... having a kid around to wriggle into the up and under bolts with a socket wrench saves your back and neck...

 

[WarDamnEagle]

Impressive that you are taking this on yourself. Looks like a little UAE dust in there.

 

[4Cruisers]

Great write-up, keep it coming.

 

[John Young]

Hi H, on our trip across America in our RJ77 the aircon would gradually stop working after about 20-30 minutes of operation. I concluded that the condenser was freezing up. My questions to you are:

1. Can you get access to clean the condenser without de pressurizing the system?
2. How hard was it to do all the removal?

 

[Honger]

Hi H, on our trip across America in our RJ77 the aircon would gradually stop working after about 20-30 minutes of operation. I concluded that the condenser was freezing up. My questions to you are:

1. Can you get access to clean the condenser without de pressurizing the system?
2. How hard was it to do all the removal?

1. No, not really. Without de-pressurizing the AC unit is pretty much stuck in there. You can't get into the AC unit module without pulling it out.
2. It was actually pretty simple to remove. The thing is that the AC is the module that MUST come out first. You can't get the blower out without first removing the AC. So no cleaning it in place... you're gonna have to de-pressurize and pull it.

 

[2fpower]

Thanks for writing this up. On my short list.

 

[umpqua]

Your neighbors don't understand you but are secretly envious.

 

[Honger]

Impressive that you are taking this on yourself. Looks like a little UAE dust in there.

Actually, this truck spent most of it's life in Oman. So what parts of Oman weren't inside the troopies of @c2dfj45 and @John Young and @MES are deposited inside mine!

 

[Honger]

Thanks for writing this up. On my short list.

Continuing on!

I've been continuing the dis-assembly, cleaning, and flushing of all components. The rear AC evaporator, mounted to the roof, was quite a task. I ended up removing the overhead console they'd built around it. It was purely cosmetic and was just in the way. Once the console was off I found this...

The pipes and expansion valve had been goobered up with some sort of asphalt-like goo. It was gross.

But after some goo gone and elbow grease I was getting it cleaned up okay. I finally resorted to mineral spirits and that cut it much quicker. Much better now...

Then I ran flush through the hoses and evaporator.

 

[Honger]

I continued removing and cleaning parts. This auxiliary valve blocks off the refrigerant on the high-pressure side when the rear AC isn't on.

I'm nearly done on cleaning and flushing smaller individual components.

Have been cleaning up and painting brackets as well.

And here's my progress on the system so far...

Remaining is to install the rear AC expansion valve, re-install all the pipes and hoses, replace the primary expansion valve, and then finally the compressor. The compressor needs to be drained of old oil and have the new R134a adapters installed.

 

[Honger]

The AC evaporator housing was split open in preparation for replacing the expansion valve... and also for a deep cleaning.

It actually cleaned up nicely after a good soak in some water and Simple Green.

I was toying with painting the housing. But now that I've seen how well it cleaned up I'm leaving it alone.

 

[John Young]

Actually, this truck spent most of it's life in Oman. So what parts of Oman weren't inside the troopies of @c2dfj45 and @John Young and @MES are deposited inside mine!

My 1998 Model 100 'Dhanno' that spent 10 years here in Dubai has now been back in Virginia for over a year. Despite the fact that we took the interior completely out, pressure washed the carpets and so on, each time I get in the truck there is a little tan sand that has drifted down over everything.

That gunk .... yuck. BTW, my Omani troopy has no rear aircon. And the front is not working at the moment either, although it was when I bought it. Being worked on now. And the tranny makes a noise like a spinning bearing above 55kph, so the poor old thing ain't drivable at the moment.

PS--given that you have two evaporators in your system, is your compressor some kind of jumbo unit?

 

[c2dfj45]

Continuing on!

I've been continuing the dis-assembly, cleaning, and flushing of all components. The rear AC evaporator, mounted to the roof, was quite a task. I ended up removing the overhead console they'd built around it. It was purely cosmetic and was just in the way. Once the console was off I found this...

The pipes and expansion valve had been goobered up with some sort of asphalt-like goo. It was gross.

But after some goo gone and elbow grease I was getting it cleaned up okay. I finally resorted to mineral spirits and that cut it much quicker. Much better now...

Then I ran flush through the hoses and evaporator.

The gunk on the expansion valve is insulation....it helps maintain a constant temp in the valve....and to not freeze up. When we install aftermarket systems, there is always a roll of this stuff that you wad around the valve once it's installed. It might be called Presstite or something. I think home AC systems use something like it too. Maybe....not sure on that.

 

[Honger]

The gunk on the expansion valve is insulation....it helps maintain a constant temp in the valve....and to not freeze up. When we install aftermarket systems, there is always a roll of this stuff that you wad around the valve once it's installed. It might be called Presstite or something. I think home AC systems use something like it too. Maybe....not sure on that.

I knew it was for insulating purposes. Presstite is indeed one of the name brands (I just looked it up). Whatever they used at the little workshop who retrofitted my AC was a no-name brand that just coagulated. Usually it's more "tape like" than this was.

Inside the Toyota AC box there is no wrapping around the valve, just a nice piece of the foam tape around the sensing bulb of the expansion valve. And the replacement Denso valve comes with a replacement piece of foam tape and the instructions just say to wrap it around the sensing bulb.

So I'm curious... should I:
1) Re-wrap the entire exposed parts of the lines to the rear AC?
OR
2) Just re-wrap the sensing bulb on the rear AC expansion valve?

Also, should I:
3) Find the Presstite, butyl-like tape to wrap things with?
OR
4) Use the foam tape style similar to what came with the Denso valve? (I already have some more of this type)

 

[Honger]

My 1998 Model 100 'Dhanno' that spent 10 years here in Dubai has now been back in Virginia for over a year. Despite the fact that we took the interior completely out, pressure washed the carpets and so on, each time I get in the truck there is a little tan sand that has drifted down over everything.

That gunk .... yuck. BTW, my Omani troopy has no rear aircon. And the front is not working at the moment either, although it was when I bought it. Being worked on now. And the tranny makes a noise like a spinning bearing above 55kph, so the poor old thing ain't drivable at the moment.

PS--given that you have two evaporators in your system, is your compressor some kind of jumbo unit?

The very fine sand/dust is called fesh-fesh in the region John. Silt is what I'd call it in American vernacular. But I just like the word fesh-fesh. I imagine it's like an Arabic onomatopoeia... a word that sounds like what it actually is.

But I digress...

The FJ75's had a factory option for a second AC and accordingly had two different factory compressors... one w/o rear AC and one w/ rear AC. Mine did NOT have factory rear AC so I imagine the original compressor was the smaller capacity one. However, I don't have the original compressor. It was replaced at some point with a Sanden compressor, SD-508 Model S8390. It's on a weird bracket they fabbed up. Maybe it was replaced because the original wasn't up to the task of handling the larger refrigerant volume. That seems logical. My secondary condenser also has it's own dedicated electric fan.

The Sanden compressor that is on the truck handled both AC's just fine when I tested them prior to removing the old refrigerant. Both blew cold at the same time. Hopefully they are just as robust with R134a.