ST185 AC system overhaul with photos

[Luvmyalltrac]

Ok, so I stated that I was going to post a thread about overhauling my AC system. So I’m going to start. I have a lot of photos and narration to include. That said, I realized that I will have to do it in installments. It would be too lengthy if done all at once. My apologies for that, and I ask for patience. I am fortunate to have a good friend who happens to be a professional auto mechanic. It is his shop, equipment and especially guidance that made it possible for me to complete this project and with success! So not long after I finally got Night Fury shipped to Texas from Maryland, I discovered that the AC was not working. Yes, it was March, but here in Central Texas we can and do get warm days throughout the year. I brought my ailing black dragon to Noah’s shop and asked him to check it out. He said a lot of technical things related to Air Conditioning, but then boiled it down to this,”you’re going to have to replace everything that you can, and thoroughly flush and clean the rest, if you want a decent chance of it working and continuing to work well“. I trust his professional judgement and had his assistance on a similar project previously. I ordered the new Denso parts from Rock Auto. I purchased AC system Flush(1/2 gallon can), AC oil(PAG 46), a multi-pack of the green R134 O-rings, and new pressure fittings with caps and schrader valves, all from O’Reilly Auto Parts. 3 weeks later(now April) I finally have an entire weekend off and just as important, Noah has time to help and an open bay in his shop! Hood up and ready to get started! My first task, after Noah evacuated the system, was to disconnect the fittings that connect the evaporator core and expansion valve to the engine bay components. There is precious little room to accomplish this between the firewall and the back of the engine. I had to carefully move the wireloom containing the engine wiring harness out of the way, so I could see whatI was doing. Backer wrenches are very important in order to avoid damaging the aluminum fittings.
Here is another view, with the fittings now loose.
The next step was to remove the evaporator core housing from behind the glovebox. I took several reference photos to be sure that I could replace all of the fasteners and wires to the correct places. There are four nuts and four bolts according to my factory service manual. After I removed all of the wiring, I removed the fasteners saving a conveniently placed one for last, so that I could support the unit as it came loose. Then with a little help from Noah, who guided the fittings through the rubber firewall grommet, I carefully removed it , keeping it tipped back to avoid spilling oil onto the floorboard.
housing removed, oil leaking out of the fittings that shows signs of metal particles in it indicating compressor failure.
That‘s all for this installment of the project. Save the thread and check back for more soon. Please leave any comments, questions or criticisms of my posting methods. Still learning and will listen to input.

 

[underscore]

This is very timely because I want to get the AC back into my car next winter. Were you able to remove the core housing without removing the entire dashboard?

 

[CTechBlueDragon]

pretty sure they build the heater core then the car around it. If you want to fix your ac just remove and replace car.

 

[Luvmyalltrac]

This is very timely because I want to get the AC back into my car next winter. Were you able to remove the core housing without removing the entire dashboard?

Yes, just four nuts(Top)and four bolts(bottom) after the wiring is disconnected. I will get more posted soon.

 

[Luvmyalltrac]

pretty sure they build the heater core then the car around it. If you want to fix your ac just remove and replace car.

Not sure about the heater core, but evaporator core and housing come out fairly easy.

 

[Luvmyalltrac]

This is very timely because I want to get the AC back into my car next winter. Were you able to remove the core housing without removing the entire dashboard?

Firstly remove door sill then remove the glove box and speaker housing To get to the evap core.

 

[Luvmyalltrac]

Now back to the project.
I have removed the evaporator core housing, now I need to remove the old core and expansion valve, then install the new one in the housing.
view of firewall where the housing was removed. Some of the fastening points can be seen, as well as the holes in the wall for the connections.

before splitting open the housing, I took care to cut the foam sealing gasket at the seams. The gasket was in very good condition.
reference photo noting location of sensors on the evap core.housing with old core removed showing how much crap can accumulate and steal efficiency.

view of core with more crap and telltale oil on the expansion valve tubing.

this one shows why there was a leak allowing oil outside of the system in this location. When this system was previously converted to R134, All of the system O-rings should‘ve been replaced with the green ones designed for R134. You can seen the old black ones that failed and were leaking at the expansion valve.
comparing new Denso components to old to insure correct fitment. Note new green o-rings supplied with the expansion valve.

to be continued

 

[Luvmyalltrac]

Just a bit more now. Want to finish posting the evap core refit.
A thin coating of pag46 oil must be applied to every O-ring prior to reassembly of parts.

View of the assembled evap core and expansion valve and cleaned and flushed tubing(more on flushing reused parts later, very important).

Opposite side view showing sensors inserted into the new Denso core at the same spot as the old one.
Views of reassembled housing with new parts. Note corks to plug tubing and keep out dust, moisture and contaminants, until ready to b reinstalled on firewall. Night Fury looks on in anticipation and approval! That’s all for now folks. More when I can. Please reply with comments, questions, critique. Thanks!

 

[Luvmyalltrac]

Its past Time to do another installment. Here goes!
Having completed the Evap core, I moved to the front of the car and removed the dryer, condenser and hard line. After removing the shielding and hood latch, horns etcetera,here is the veiw.
next I removed the bolts holding up the Tranny oil cooler, and fan motor.

some PB Blaster was used to encourage some bolts loose, as evidenced by wet spots.
Next I removed the hard line attached to the top of the receiver/dryer. Look at the ugly stuff that came out! The dark colored stuff is more evidence of metal in the system likely due to compressor failure.
The dryer was being replaced, but I reused the line, so I cleaned it thoroughly with the flush. Next I removed the condenser, very carefully, since this part was to be reused and is not easily sourced. I failed to get photos of the removal process, but recall that it was not too difficult. Once out I had to do my best to thoroughly flush the condenser. I relied on friend and mentor Noah, who provided this awesome device to use with the flush.
you fill the container with the flush and connect it to an air compressor. Then I placed it over an oil drain pan and blasted flush into one end of the condenser
This is a messy job, I had to used eye, and skin protection. After this photo was taken, i switched to heavy duty nitrile gloves. The process of cleaning the condenser, took awhile. I repeatedly filled it with flush, picked it up and sloshed it around, back and fort, tilted left right, shook it. Then drained it out. Then repeat. Blast it from the opposite side, shake, tilt, tip, drain, repeat. Repeat again. You get the idea. Nope, still not clean, repeat, repeat. Finally, I was satisfied that I had done the best I could. Stood it up over the drain pan to drip, while moving onto the next steps. The can of flush was one gallon. I used about half of it on the condenser. Another quart or so on the various lines.
That‘s all for now. Hope to continue soon!

 

[Paulytunes]

Wow! That is an impressive amount of work!

 

[Luvmyalltrac]

Wow! That is an impressive amount of work!

I was very motivated living in Texas with summer coming and all…

 

[RedCelicaTRD]

I’ve never had any of the HVAC out of the car before. I found it pretty interesting that the evap housing just slides in. Makes sense though. Not all cars had A/C from the factory, but it was available as a dealer installed kit. I always assumed the whole dash came out to install it, which would have been crazy expensive to install for an accessory.

 

[Luvmyalltrac]

I’ve never had any of the HVAC out of the car before. I found it pretty interesting that the evap housing just slides in. Makes sense though. Not all cars had A/C from the factory, but it was available as a dealer installed kit. I always assumed the whole dash came out to install it, which would have been crazy expensive to install for an accessory.

I know this is true. When I shopped for my compressor, there were two different part numbers for the car, one said “factory installed ac”and the other,”dealer installed ac”.

 

[Luvmyalltrac]

I will post the final installment of this project soon. I had intended to do so over the holiday weekend, but different automotive project took most of it up. Fuel tank replacement in the jewel of my fleet!

 

[Gert]

Very nice work.
Once I replaced my heater core in the core unit (no airco) and I removed the entire dashboard. It looks you were able to remove the core without removing the dash?

 

[Luvmyalltrac]

Yes, the evaporator core for the AC system on my car is made to be removed/installed without need to remove the entire dash. I used my Toyota factory service manual to do it. Just followed the steps in the book. The heater core is connected to your car’s engine coolant system and has water flowing through it instead of refrigerant.

 

[Luvmyalltrac]

Yes, the evaporator core for the AC system on my car is made to be removed/installed without need to remove the entire dash. I used my Toyota factory service manual to do it. Just followed the steps in the book. The heater core is connected to your car’s engine coolant system and has water flowing through it instead of refrigerant.

Water and antifreeze to be exact.

 

[Luvmyalltrac]

So now then, back to the project. I am ashamed of the amount of time it has taken, but I do what I can. My life is busy, and I work more hours than I really want to which leaves less time for the more enjoyable stuff.
with the condensor cleaned out I turned my attention to replacing the compressor. First, I removed the alternator and it’s ductwork. Then I realized that I would need to remove the bottom radiator hose, so I drained the radiator. In retrospect, to save time, I could‘ve started the draining then removed the alternator while the coolant drained.🙄
You can see above that I removed the bolts holding the hard lines to the compressor before removing the alternator. This is because I didn’t bother the use my FSM to guide me and just tore into it. Learn from my errors. If you have the book, use it. It will save you time and frustration.
I also moved the relay box from it’s mount to make more room to work. And a photo of the alternator removed and wiring laid on top of the intercooler
Then I removed the compressor through the bottom. See photos below of the dirty removed compressor the space where it was, and removal of the manifold that must be cleaned and reused on the new compressor. Now with the compressor out, I was able to use the flush with the previously shown tool to blow the remaining hard lines out while they remained in place. To prevent this nasty mess from invading my car interior via the holes in the firewall, I put a piece of cardboard between the line and the firewall and then blasted away till clean. One thing to note here is that the AC trinary switch is attached to the hard line back near the firewall. It had shown signs of leakage (probably because it had the old black o-ring from it‘s days as part of an R12 system). I removed it prior to blasting the line clean, then cleaned it and replaced the o-ring with a fresh green one. Pag46 oil was applied before reinstalling it on the cleaned line.
look closely in the large photo above( cardboard against firewall). You can see the trinary switch still attached to the line before I removed it for the cleaning. It is in shadow in the photo, so not easily identified. Top left with small blue label on it.
thats all for now. The final installment will cover compressor prep, installation,final assembly of the system and then vacuum testing and charging the system.

 

[Luvmyalltrac]

So now the old compressor is out and the manifold cleaned. My mechanic mentor, Noah removed the shipping plate that was where the manifold mounts And began to drain the shipping oil out of the new compressor. Getting the shipping oil out takes some doing. Drain, turn pully to pump more out. Repeat. Be sure to drain into a container to measure the amount. This is compared to what the FSM states the oil capacity is. The same amount of new oil is put into the new compressor, with the balance of the system capacity put into the new drier( was about 1 ounce).
New compressor after draining the shipping oil.

Now with pag46 oil added, (same amount as removed shipping oil) And cleaned manifold installed.

balance of system oil is added to the New drier.
Next the drier was installed into the bracket in front of the reinstalled, cleaned condenser.
Condenser replaced awaiting drier install.
I had some trouble with some of the mounting bolts around the lower part of the condenser. So I made use of anti-seize compound on all bolts when I reinstalled them. Clean the bolts with a wire brush and brake cleaner first. You don’t need a
lot of anti-seize it just gets messy, be sparing.
New drier installed with hard lines attached.
Next I installed the new compressor from the bottom, carefully, so as not to spill the oil out. then reattached those hard lines to the manifold.
New compressor in place.
relay box, alternator and it’s ductwork, plus lower radiator hose reinstalled.
hood latch, bracket, horns and fan all replaced.

Evaporator core and housing replaced with all wires reconnected. Then connected to hard line fittings just outside the firewall. This was accomplished with much contortion and the improper language that accompanies challenging automotive service of a difficult nature.😫😖😡🤬

 

[Luvmyalltrac]

With the system completely reassembled, all bolts tightened, the belt tensioned, coolant strained and returned to the radiator, Noah connected the magic AC machine and pulled a vacuum.

Night Fury waits in anticipation as vacuum test is underway. The vacuum held satisfactorily and he then charged the system with R134 refrigerant. Meanwhile, I sat in the driver’s seat and watched as the needle on my thermometer began to drop!
I am happy to relate that the project was a complete sucess! We completed the job on With the system completely reassembled, all bolts tightened, the belt tensioned, coolant strained and returned to the radiator, Noah connected the magic AC machine and pulled a vacuum April 15th, 2023. I have driven Night Fury regularly since then and I use the auto-AC function all the time. It is now June in central Texas and I can enjoy driving in comfort! Thanks to all who read! Please comment, ask questions and like 👍 if you please.