First time AC rebuild/convert, need some advice (1 Viewer)

[Skniper]

1990 FJ62... AC not working, compressor not firing. Pressed the schrader valves on the compressor and nothing came out. Suspect the system has simply leaked out over time with age and extended periods of not being used. Still (was) running r12.

Considering having a shop draw down the system as is, recharge it and see what happens. If it holds, great, if not then the fun begins....OR...(since the system may leak out anyway)...should I skip that and just start planning to convert to 134a?? I want to do most of the wrench turning conversion work myself then have a shop gas the system. Searched and read a ton...will call Coolstream for parts.

Questions:
- I really want to pull the evaporator to clean 27 years of crud out, guessing I should replace the expansion valve while I'm there? Anything else while I have it out?
- How many o-rings are in the system? ...and where are all of them? I can see most of the pipe/hose junctions, just wondering if there are any o-rings that are not obvious.
- Should I pull the compressor to drain the old oil? Or can the shop flush the compressor without removing it?
- Will replace the drier with a new 134a unit and replace schrader valves with 134a valves.
- Condensor...is there anything to do here other than replace o-rings? Flush? Shop flush?
- Flushing? Do the components need to be flushed out individually, or can the shop flush the whole system at one time?? Trying to minimize the shop turning any wrenches.

Anything else?
Did lots of reading, just some specifics that need some clarification. Thanks.

 

[LAMBCRUSHER]

get or ing kit from coolstream. get evap and expansion valve. there is a pressure/thermo switch in the case I did not replace. the oring locations are easy to see. if you're taking apart enough to get to the core, you'll see all the junctions for the orings. replace the rings, core and valve; buy a new dryer and make sure the comp is up to snuff. if you stay r12 then don't worry about flushing. if you convert, then flush flush flush. make sure the system doesn't leak and the comp will work and charge it. if you canb find r12, it isn't so expensive that it's more than the extra work involved in flushing the r12 oil prior to 134a...hope that helps. PS, clean the crud out of the blower house/ suitcase...it's an illness waiting to happen. not to mention, you want the air to move, don't you?

 

[red66toy]

Everything @LAMBCRUSHER said. I am doing this exact thing now. So I have just a couple things to add: if you are taking out the AC evap box replace the little high pressure switch as well, it sits on the same pipe as the expansion valve. It cost like $5 and just do it while you are in there because you don't want to go back in there again, especially for a tiny cheap switch.
Follow the FSM to get the box out, it's tight but it will come out if you go slow.
I bought most of my parts from Coolstream. Very helpful, I spoke with Jorge.
If you do convert to r134a then you will have to remove the compressor, drain out the mineral oil and add pag46 oil. Also oil the little o-rings as you replace them in the system.

Edit: since you are still r12, stick with it if you can (most people seem to do that, but it is more expensive and harder to find). Mine was already converted to 134a so I am sticking with that.

 

[Skniper]

Thanks @LAMBCRUSHER , I read some of your posts while searching. So that is my dilemma @red66toy , jump right into 134a convert or stick with r12. (??) Just wondering whats better/easier to deal with in the long run.

Question: Are the new green 134a o-rings compatible with r12?? At the very least I really want to remove and clean the evaporator, with new exp valve and pressure switch while I'm there. If compatible with r12, I can use new O rings on the evap connections. At least I get that huge pain in the ass part of the job done and can just run r12 for now to get it going. If I need to convert later then it's just all the forward external pieces under the hood to deal with.

Thoughts?

 

[red66toy]

Thanks @LAMBCRUSHER , I read some of your posts while searching. So that is my dilemma @red66toy , jump right into 134a convert or stick with r12. (??) Just wondering whats better/easier to deal with in the long run.

Question: Are the new green 134a o-rings compatible with r12?? At the very least I really want to remove and clean the evaporator, with new exp valve and pressure switch while I'm there. If compatible with r12, I can use new O rings on the evap connections. At least I get that huge pain in the ass part of the job done and can just run r12 for now to get it going. If I need to convert later then it's just all the forward external pieces under the hood to deal with.

Thoughts?

In the long run r134a will be easier to deal with I believe and more readily available. Some shops wont touch r12 for repairs (at least in seattle). As for doing the conversion now or later, if you can get a shop to do the r12 then maybe just stick with that and convert later if you need? Since r134a requires a better sealed system, I would think the r134a o-rings would be more than fine with r12 but I would confirm with Coolstream and see what they say. You will be happy you cleaned the evap, mine was NASTY.

 

[Skniper]

Haha...to clarify I don't *want* to pull the evaporator, but my curiosity of how dirty it may be and how much better it could be has me pushing forward. Onward!

 

[red66toy]

Maybe try and pull the blower housing then at least and try and vacuum out the evap housing with a hose. Then have a shop vacuum test the system?

 

[Aloha Jen]

Having just completed redoing my entire AC system, I have a couple suggestions. First, before you do anything or start replacing parts, you need to find the leak(s) in the system. Empty AC systems never just need a charge, they have leaked out somewhere in the system. If it's just an O-ring somewhere, you got off easy and is a quick fix. But odds are it is something else, like the compressor, evaporator, expansion valve, pressure switch, dryer, or condenser. But all are easy to replace and readily available....quality Denso parts for all I mentioned can be found on Amazon. I replaced all, and shipped free to me in Hawaii through Amazon Prime.

There are also non obvious o-rings to remember, on the pressure switch, the expansion valve, the small coolant pipe that attaches to evaporator, and the some on top of the compressor under the discharge/suction ports. All these will need to be replaced with r134 compatible o-rings if you convert to r134. Here are some of the areas on the evaporator you will find the o-rings and the different parts that connect to it:

To get the evaporator box out, it can be a little difficult and time consuming, but it will come out if you get all of the necessary things out of the way. Sometimes you have to get up in there though!

The entire AC system can be worked on with pretty simple hand tools, and the system can be vacuumed and charged with free loaner tools from Autozone. Don't know if you have one of those by you, but they will loan you the gauges and vacuum pump to do the job yourself. They gave us 90 days to return them, but don't know if it's different on the mainland.

Once all the leaks are addressed, o-rings swapped out, r134 fittings on your compressor, and r134 compatible oil added(if your parts are new or have drained your old compressor), you can vacuume the system and charge it with r134 cans. Mine took two cans of r134($7 each) to get the pressure on the gauges right and to get the AC to blow 44 degrees out the vents. It's so nice to have ice cold AC when driving in the 60!

 

[red66toy]

Nice info Jen! Quick question, did you use a new Denso drier or another one? Thanks!

Having just completed redoing my entire AC system, I have a couple suggestions. First, before you do anything or start replacing parts, you need to find the leak(s) in the system. Empty AC systems never just need a charge, they have leaked out somewhere in the system. If it's just an O-ring somewhere, you got off easy and is a quick fix. But odds are it is something else, like the compressor, evaporator, expansion valve, pressure switch, dryer, or condenser. But all are easy to replace and readily available....quality Denso parts for all I mentioned can be found on Amazon. I replaced all, and shipped free to me in Hawaii through Amazon Prime.
View attachment 1479322
There are also non obvious o-rings to remember, on the pressure switch, the expansion valve, the small coolant pipe that attaches to evaporator, and the some on top of the compressor under the discharge/suction ports. All these will need to be replaced with r134 compatible o-rings if you convert to r134. Here are some of the areas on the evaporator you will find the o-rings and the different parts that connect to it:
View attachment 1479325
View attachment 1479326
To get the evaporator box out, it can be a little difficult and time consuming, but it will come out if you get all of the necessary things out of the way. Sometimes you have to get up in there though!
View attachment 1479324
The entire AC system can be worked on with pretty simple hand tools, and the system can be vacuumed and charged with free loaner tools from Autozone. Don't know if you have one of those by you, but they will loan you the gauges and vacuum pump to do the job yourself. They gave us 90 days to return them, but don't know if it's different on the mainland.
View attachment 1479323
Once all the leaks are addressed, o-rings swapped out, r134 fittings on your compressor, and r134 compatible oil added(if your parts are new or have drained your old compressor), you can vacuume the system and charge it with r134 cans. Mine took two cans of r134($7 each) to get the pressure on the gauges right and to get the AC to blow 44 degrees out the vents. It's so nice to have ice cold AC when driving in the 60!

 

[Aloha Jen]

Nice info Jen! Quick question, did you use a new Denso drier or another one? Thanks!

Good catch! The dryer is the only non new Denso part on the whole system. The reason we opted for aftermarket (4 Seasons) on that was because I believe the Denso drier comes filled with r12 oil. We didn't feel like draining it and refilling and apperently it's not good for those to be open and exposed to air too long. The one we got came filled with r134 compatible oil. That one is a bit skinnier as well, so was wrapped once with insulated foam to fit snug in the dryer bracket. But both Denso and aftermarket ones are very inexpensive. Here's the one I got:
Amazon.com: Four Seasons 33403 Filter Drier: Automotive

 

[red66toy]

Good catch! The dryer is the only non new Denso part on the whole system. The reason we opted for aftermarket (4 Seasons) on that was because I believe the Denso drier comes filled with r12 oil. We didn't feel like draining it and refilling and apperently it's not good for those to be open and exposed to air too long. The one we got came filled with r134 compatible oil. That one is a bit skinnier as well, so was wrapped once with insulated foam to fit snug in the dryer bracket. But both Denso and aftermarket ones are very inexpensive. Here's the one I got:
Amazon.com: Four Seasons 33403 Filter Drier: Automotive

Interesting, I was wondering about the new Denso drier. Glad I didn't run it yet! Thanks.

 

[1978FJ4O]

@Aloha Jen We need a full write up with part numbers, where you ordered parts from and oil amounts. I need to do this on my HJ60 as well.

 

[red66toy]

This should help get you started: MUD

 

[Skniper]

Thanks for the info @Aloha Jen ...great photos of the new parts. I agree my system has probably leaked out and a refill is probably foolish. I'm trying not to just blindly throw part$ at it, but I am definitely pulling the evap under the dash regardless of system condition to clean it....and that is definitely a 'take care of other stuff while you're in there' kind of job, soooo I'll definitely replace the expansion valve and probably the press. switch and have the coil vacuum/pressure tested while it's out. After the under dash stuff is buttoned up, I'll take a much more 'scientific' approach to finding any leaks or other problems....I guess that's when I have to decide on 134a vs r12.

Speaking of the pressure switch...is that what is in the small OEM Toyota box in your second photo?

I'm not worried about the gauge manifold set up...I'm leaving the vacuum and charging to the pros. I'm just turning the wrenches. May take the time to learn that process after I get this thing going again.

 

[Skniper]

@Aloha Jen We need a full write up with part numbers, where you ordered parts from and oil amounts. I need to do this on my HJ60 as well.

Lots and lots of threads about doing this.....I never found one that really detailed much info, and you have to search several different word combos to find things. So yeah, one really good AC rebuild thread with good photos would be nice.

Three days ago I would have NEVER touched the AC system, never worked on one, scared of it and only had a vague understanding of how they work and what the components are. I read the AC chapter in the FSM and read a sh#t ton of the above mentioned threads piecing the info together. Actually can't wait to tear into now and get it tightened up.

 

[Aloha Jen]

Speaking of the pressure switch...is that what is in the small OEM Toyota box in your second photo?

Yes. Mine was a 24v version I believe, as it was a different part number then the FJ60 pressure switch.
24v HJ60 pressure switch:

Pressure switch for FJ60

Lots and lots of threads about doing this.....I never found one that really detailed much info, and you have to search several different word combos to find things. So yeah, one really good AC rebuild thread with good photos would be nice.

Three days ago I would have NEVER touched the AC system, never worked on one, scared of it and only had a vague understanding of how they work and what the components are. I read the AC chapter in the FSM and read a sh#t ton of the above mentioned threads piecing the info together. Actually can't wait to tear into now and get it tightened up.

I also had to go through a bunch of different threads to find all the info we needed. Mine was a bit more complicated because my 60 didn't have AC ever, so had to start from scratch. A comprehensive write up would have been helpful.

 

[1972FJ55]

Interesting, I was wondering about the new Denso drier. Glad I didn't run it yet! Thanks.

The Denso drier uses desiccant that isn't compatible with R134a. They make a retro-fit drier but it's only available through Toyota dealers at some exorbitant price. Aftermarket driers use media compatible with both refrigerants.

 

[red66toy]

Thank you for confirming this!

The Denso drier uses desiccant that isn't compatible with R134a. They make a retro-fit drier but it's only available through Toyota dealers at some exorbitant price. Aftermarket driers use media compatible with both refrigerants.

 

[Skniper]

Got a new Denso expansion valve, green o-ring kit, and Denso drier/rec on the way from Coolstream. Coolstream says that drier is compatible for r12 or 134a, btw.

They don't have the thermistor/pressure switch.....searched.....anyone know the part # for an FJ62 pressure switch??
Is this still available from Toyota?

 

[Aloha Jen]

They don't have the thermistor/pressure switch.....searched.....anyone know the part # for an FJ62 pressure switch?? Is this still available from Toyota?

Look up 3 posts ago.