ST185 AC system overhaul with photos

Luvmyalltrac

Active member
I’m impressed by your effort here. Congrats!
Thanks Roreri! I am pleased it went well. Again, my success was heavily dependent on the facilities, tools and knowledge of my good friend, Noah! That is his 1970,72? Dodge Demon in the background of my avatar.
 

grip-addict

Active member
Would you happen to have the part numbers handy and be willing to share them please? I found the major stuff on rockauto, but Incidentals and gaskets from oreillys I wonder about. The one near me is quite unreliable.

Mine at least gets cool after a r134 charge, but the pressure does not last thru the night :(.
 

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Luvmyalltrac

Active member
Would you happen to have the part numbers handy and be willing to share them please? I found the major stuff on rockauto, but Incidentals and gaskets from oreillys I wonder about. The one near me is quite unreliable.

Mine at least gets cool after a r134 charge, but the pressure does not last thru the night :(.
Sorry, for slow response. my work weeks have been in the high 60’s to 70+ hours, so just don’t have much free time. I got my compressor, expansion valve/ evap core, and the drier from Rock Auto. The o-Ring was just a generic assortment kit from O‘reilly, as were the gallon jug of flush and the pag46 oil. So my question is, “what part numbers do you want, if you already found the major parts on Rock Auto?”. I will be happy to help, just not clear on what you want.
 

Luvmyalltrac

Active member
Would you happen to have the part numbers handy and be willing to share them please? I found the major stuff on rockauto, but Incidentals and gaskets from oreillys I wonder about. The one near me is quite unreliable.

Mine at least gets cool after a r134 charge, but the pressure does not last thru the night :(.
 

yyonline

Member
I'm tacking this project myself, and need a sanity check on something. Does anything plug into the connector highlighted below? I can't find the mating plug for this anywhere. I also can't find it on the 1992 wiring diagram. I took lots of photos for reference as well, but none of my photos show this connector. I'll be adding some notes to this thread once I finish my project soon.
Screenshot_3.png
 

Luvmyalltrac

Active member
I'm tacking this project myself, and need a sanity check on something. Does anything plug into the connector highlighted below? I can't find the mating plug for this anywhere. I also can't find it on the 1992 wiring diagram. I took lots of photos for reference as well, but none of my photos show this connector. I'll be adding some notes to this thread once I finish my project soon.
View attachment 8053
I am not certain, but I will take a look at mine tomorrow. I do seem to remember one unused connector, but it has been to long for me to say for certain without looking. I will post a response as soon as I can.
 

Luvmyalltrac

Active member
IMG_0124.jpeg
I am not certain, but I will take a look at mine tomorrow. I do seem to remember one unused connector, but it has been to long for me to say for certain without looking. I will post a response as soon as I can.
Apologies for the delay. Above is a photo that shows nothing connected to that same harness on my car with a complete and working AC system.-Tim
 

yyonline

Member
I just finished refurbishing the AC system on my 92 All-trac after I lost my refrigerant due to a leak. The previous owner converted it to R-134a. Given that I have still have R-12 available, I decided to flush all the lines and bring it back to the factory-spec R-12 refrigerant.

The original compressor was leaking from the shaft seal. I got a new Denso compressor. I leared that R-12 mineral oil ND-Oil 6 is still available in Japan, but can't be shipped to the USA since 2011 due to a missing environmental data sheet. The service manual says that Suniso 5GS is also compatible, so I acquired some of that. I also added some UV dye to the compressor to make any future leaks more obvious.
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The condenser appears to be no longer available. However, I had a new condenser in my parts stash acquired from Toyota back in 2014, when they were still available.
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The power steering cooler and transmission cooler both need to be moved out of the way to remove the condenser. You don't need to disconnect either one, just unbolt them from the lower radiator support.
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There isn't much room to work to unbolt the AC lines at the firewall. I think I used several different brands of wrenches, all with slightly different angles, to accomplish the task. I installed a new Denso evaporator and expansion valve.
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My evaporator hosing gaskets were in rough shape. I found some from another model I was able to make work. Toyota part number 88578-60130. They are very fat when new, but are very soft and compress down to size once the housing is installed in the car. I learned that the All-trac only uses the black-wire thermistor. The green-wire thermistor is used by the GT and GT-S ECU, but not on the All-trac. In theory, you could leave the green thermistor out with no ill effects.
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When doing this job, I learned that my external temperature sensor wire was broken due to rubbing on a bracket. I wonder how long this has been broken for. I repaired the wires and installed a new connector. The original connector was discontinued, so I found a similar connector that worked.
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The information in this thread was helpful in completing this project. I'll complete a second post with additional information that may be helpful to others, as I'm hitting the attachment limit for this post.
 
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yyonline

Member
If you convert to R-134, HNBR o-rings are preferred. Prior to 1992, Toyota used NBR o-rings. Starting in 1992, Toyota switched from NBR o-rings to HNBR o-rings. Toyota's NBR o-rings were originally black. Their HNBR o-rings are brown. My 92 had a mix of black and brown o-rings, so it was produced during the transition. Current replacement o-rings from Toyota are brown HNBR o-rings. Aftermarket HNBR o-rings are generally, but not always, green.

I found a TSB AC92-004 that specifies the color and material change for the o-rings:
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There are some 'hidden' o-rings that aren't on the diagrams.

Where the high-side service port screws into the block joint above the receiver/drier:
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Where the lead-filled fuse bolt screws into the block joint above the receiver/drier:
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Where the pressure relief valve screws into the compressor manifold:
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Toyota part numbers for o-rings:

Evaporator x Expansion valve: Qty 2 of 90099-14045
Expansion valve x Tube Assy: 90099-14045 and 90099-14044
Tube Assy x Liquid pipe: 90099-14044
Tube Assy x Suction pipe: 90099-14045
Pressure Switch x Liquid pipe: 90099-14056 (*1)
Suction pipe x Suction hose: 90099-14045
Suction hose x Compressor manifold: 90099-14045
Discharge hose x Compressor manifold: 90099-14046
Discharge hose x Condenser: 90099-14046
Condender x Liquid pipe A: 90099-14046
Liquid pipe x Receiver/drier: 90099-14044
Receiver drier x Liquid pipe B: 90099-14044
Liquid pipe B x Liquid pipe: 90099-14044
Liquid pipe B x High-side service valve: 90099-14056 (*1)
Compressor manifold x Pressure relief safety valve: 90099-14056 (*1)
Liquid pipe B x Fuse bolt: 88475-12020 (*2)
Compressor manifold x compressor: Not available separately from Toyota. Use Honda #38839-PR7-A01:
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*1. Toyota claims that 90099-14056 is a 9.25mm ID x 12.81mm OD o-ring. This equates to a #012 standard o-ring, which is nominally 3/8" size. However, Toyota's o-ring is on the thin side. I ended up using TSI part #77147, which is a little thicker than the Toyota o-ring.
*2. This part number is for the fuse bolt and the o-ring, and it's not cheap. It is a 8.8mm ID x 1.9mm thick o-ring:
IMG_3597.jpg

The Toyota suction hose has some heat insulation around it. Mine was pretty degraded. Aftermarket hoses don't come with the heat insulation. I used Thermo-Tec Thermo-Flex Aluminum Heat Shield Sleeve 17150, which is an exact match to the factory insulation in size, and very close in overall appearance.
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I have a low-milage GT-S, and I used that for reference to see how the compressor wires are routed. Here's how they go:
IMG_3368.jpg
 
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etantshi

Moderator
Great work on this project. I've been trying to source the HP and LP hose ends to create custom AC soft lines. Do you know if they follow some sort of standard (Denso or otherwise)?
 

Roreri

Active member
What a great job. Congrats on restoring that Texas-critical system!

I think all of us who have gone to R-134 are going to be looking at doing a similar job at some point or other because of the o-rings if nothing else. Damn.
 

Luvmyalltrac

Active member
Great work on this project. I've been trying to source the HP and LP hose ends to create custom AC soft lines. Do you know if they follow some sort of standard (Denso or otherwise)?
Thank you, I wish that I could answer your question, but i do not know. If you are successful, be sure to post about it on a thread of your own! Give back to the forum when you can.
 

Luvmyalltrac

Active member
What a great job. Congrats on restoring that Texas-critical system!

I think all of us who have gone to R-134 are going to be looking at doing a similar job at some point or other because of the o-rings if nothing else. Damn.
Thanks Roreri, I hope what I did can help others. Unfortunately in my case, I did not get any lasting benefit out of it( see thread “minor disaster strikes night fury”). The AC still works fine on a car that will likely never take to the road again thanks to a devastating wreck that we suffered as reported toward the end of that thread. I am about to start a new thread related to that tragedy.
 
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