Complete A/C system replacement? (1 Viewer)

[flintknapper]

I have a HDJ81 Jap import, I think I understand the system now but two things I still don't understand..
1. Where is the evaporator?
2. How do you actually flush the system as my pipes were left open when I bought the truck, I am replacing all parts but not sure how to do it. Also how to I fill it with hat kit at the end?

You're asking for a complete tutorial on repairing/replacing your A/C system.

You can use the 'search' function here (80 series forum) and type in key words (I.E. evaporator) and it will pull up relevant posts.

To answer your first question: The evaporator is housed in a black plastic box/housing under the dash, behind the glove compartment door.

Your second question is more involved and rather than type out the entire procedure....just search here. Your model is a diesel engine and I will assume the vehicle is right hand drive. So some differences from our petrol, left hand drive vehicles is to be expected....BUT the principles of the A/C system will be the same.

 

[baldilocks]

I have a HDJ81 Jap import, I think I understand the system now but two things I still don't understand..
1. Where is the evaporator?
2. How do you actually flush the system as my pipes were left open when I bought the truck, I am replacing all parts but not sure how to do it. Also how to I fill it with hat kit at the end?

The evaporator and thermal expansion valve are both located beneath the dash on the passenger side. I’m not sure about the proper way to flush the lines other than using compressed air.

 

[flintknapper]

so i emptied the new compressor of oil. it even states to in its manual. only about 4oz. came out. @flintknapper you have been saying 8oz needs to go in a new compressor so i split it and started to put in 6oz into the H chamber (the larger of the two). but it seems to only want to take about 4oz. is it just really slow to fill? turning the clutch causes bubbles but no movement of the oil. does it matter which chamber it goes into? both? please advise...thanks!

NO....the entire system takes about 8ozs. (80 series) U.S. Spec. A new/replacement compressor will come with 'some' amount of oil in it. Typically the compressor will contain about 4 ozs of that and the rest of the components (Condenser, Evaporator, Drier and Lines) will have the rest. So if replacing ONLY the compressor.....drain the old compressor, measure the amount and add the same amount of NEW oil to the new compressor after having drained it first.

 

[Yota76]

For Canadians. Do you order replacement parts locally or from rockauto?

 

[booradley]

Without going into specifics, my A/C is shot, and it must be assumed all components will need to be replaced. A shop has quoted me too large an amount to do the work. They are being cooperative but I think they are a little intimidated by the evaporator ("looks like we will have to take the dash apart"). Otherwise they are willing to meet me in the middle somewhere.

I have read this thread and several others. I think I can replace the evaporator, expansion valve, condenser, and drier. I do not trust myself at all to vacuum and charge the system.

If I replace those components and block the lines with tape or plugs, would that be a reasonable place to let the shop take over and install the compressor, flush the lines, seal it up, and charge it?

 

[flintknapper]

Without going into specifics, my A/C is shot, and it must be assumed all components will need to be replaced. A shop has quoted me too large an amount to do the work. They are being cooperative but I think they are a little intimidated by the evaporator ("looks like we will have to take the dash apart"). Otherwise they are willing to meet me in the middle somewhere.

I have read this thread and several others. I think I can replace the evaporator, expansion valve, condenser, and drier. I do not trust myself at all to vacuum and charge the system.

If I replace those components and block the lines with tape or plugs, would that be a reasonable place to let the shop take over and install the compressor, flush the lines, seal it up, and charge it?

Dash does not have to come apart on an 80 series in order to remove the evaporator. But the evaporator does have to come out to replace the TXV (expansion valve). So.....you might make them aware of that and have them re-figure the estimate.

Most shops will not work 'behind' customer work on the vehicle, or if they do, NO warranty will be available.

 

[booradley]

Dash does not have to come apart on an 80 series in order to remove the evaporator. But the evaporator does have to come out to replace the TXV (expansion valve). So.....you might make them aware of that and have them re-figure the estimate.

Most shops will not work 'behind' customer work on the vehicle, or if they do, NO warranty will be available.

I understand about the evaporator and expansion valve. I'm just trying to save some money. They are A/C specialists, not land cruiser specialists.

 

[ZackR]

I understand about the evaporator and expansion valve. I'm just trying to save some money. They are A/C specialists, not land cruiser specialists.

If they specialize in AC you could always ask them what their price would be to vacuum and charge the system once you replaced the parts. They would know pretty quickly if there were any leaks when pulling vacuum, and if there are leaks then they wouldn't fill the system with refrigerant.

Replacing the evaporator is an annoying job since its under the dash but its not particularly difficult.

 

[booradley]

If they specialize in AC you could always ask them what their price would be to vacuum and charge the system once you replaced the parts. They would know pretty quickly if there were any leaks when pulling vacuum, and if there are leaks then they wouldn't fill the system with refrigerant.

Replacing the evaporator is an annoying job since its under the dash but its not particularly difficult.

OK thanks. Based on what I know, the whole system is contaminated and blocked somewhere. From what I have read on here it is imperative to get all the contamination out and keep it clean until it can be sealed up and charged. If I replace these components and keep them sealed with tape or plugs that takes care of most of the involved $$$ work. To me that seems to be a good place to stop and take it down and let them properly flush the lines, seal it up, and charge it (which is beyond the scope of my ability). I just need a little affirmation.

Edit: Also, I'm having a hard time running down a Denso 476-0045 evaporator. All of the usual places are out right now.

 

[RiverCityDave]

OK thanks. Based on what I know, the whole system is contaminated and blocked somewhere. From what I have read on here it is imperative to get all the contamination out and keep it clean until it can be sealed up and charged. If I replace these components and keep them sealed with tape or plugs that takes care of most of the involved $$$ work. To me that seems to be a good place to stop and take it down and let them properly flush the lines, seal it up, and charge it (which is beyond the scope of my ability). I just need a little affirmation.

Edit: Also, I'm having a hard time running down a Denso 476-0045 evaporator. All of the usual places are out right now.

Some of the purists will pounce on me for saying this, but the LC80 AC system is not complicated. I have been maintaining mine at home for many years. I live in Texas, and a well-functioning AC is essential to my happiness. Denso is good to have. I always use it in mine when I can, but you run what you can get at the end of the day.

If you are in a tight spot financially (and it happens), replace what you can, don't unseal the drier canister, call around until you find a sympathetic general mechanic shop, or MAYBE an AC specialist, and go with it. AC work isn't voodoo; it's some of the most straightforward stuff on older cars and trucks since nothing runs through the ECU or anything. The only variable in the LC80 is the pressure switch on the driver's front fender, and there is a good chance that it is your blockage unless your compressor fails. If your compressor failed and sent debris through the system, you might consider just disconnecting every fitting and pushing compressed air through each line section. Understand that this won't qualify as a flush because the compressed air will introduce a little moisture, but it will push solid debris out, and you'll have the chance to renew old O-rings at the fittings, which after 28 ish years are probably crusty and dry.

As to your Evap core, Rockauto has a "Nissens" that I'd run without hesitation on a nonshow car, which I'd assume you have, but in a financial crunch, that UAC for half the price will be fine, too.

Good luck, bro. Feel free to DM me to avoid the KIAS.

 

[booradley]

Some of the purists will pounce on me for saying this, but the LC80 AC system is not complicated. I have been maintaining mine at home for many years. I live in Texas, and a well-functioning AC is essential to my happiness. Denso is good to have. I always use it in mine when I can, but you run what you can get at the end of the day.

If you are in a tight spot financially (and it happens), replace what you can, don't unseal the drier canister, call around until you find a sympathetic general mechanic shop, or MAYBE an AC specialist, and go with it. AC work isn't voodoo; it's some of the most straightforward stuff on older cars and trucks since nothing runs through the ECU or anything. The only variable in the LC80 is the pressure switch on the driver's front fender, and there is a good chance that it is your blockage unless your compressor fails. If your compressor failed and sent debris through the system, you might consider just disconnecting every fitting and pushing compressed air through each line section. Understand that this won't qualify as a flush because the compressed air will introduce a little moisture, but it will push solid debris out, and you'll have the chance to renew old O-rings at the fittings, which after 28 ish years are probably crusty and dry.

As to your Evap core, Rockauto has a "Nissens" that I'd run without hesitation on a nonshow car, which I'd assume you have, but in a financial crunch, that UAC for half the price will be fine, too.

Good luck, bro. Feel free to DM me to avoid the KIAS.

This is good stuff. Thanks. I'm sending you a DM to sort some nitnoid details.

 

[RC51]

OK thanks. Based on what I know, the whole system is contaminated and blocked somewhere. From what I have read on here it is imperative to get all the contamination out and keep it clean until it can be sealed up and charged. If I replace these components and keep them sealed with tape or plugs that takes care of most of the involved $$$ work. To me that seems to be a good place to stop and take it down and let them properly flush the lines, seal it up, and charge it (which is beyond the scope of my ability). I just need a little affirmation.

Edit: Also, I'm having a hard time running down a Denso 476-0045 evaporator. All of the usual places are out right now.

out of all the work ive done on the truck, the AC system is the easiest. If you do more research there is a few threads that answers all your questions. The only thing you need the AC shop for is to drain and refill.

 

[jpoole]

Not sure where you are on all of this but I put together the guide below when I updated the AC on my 80 a few years ago. The thread below includes parts and material prices as well as information on where to source the few specialty tools you need and how to perform all work. Since you can get the specialty tools for free essentially your most economical option is going to be to do this yourself if you are capable.

FZJ80, R134A Air Conditioning System Rebuild How To

Thanks to the contributions of many very knowledgeable ih8mud contributors I was able to refresh the AC on my 1997 FZ 80. A few of those contributors surely saved me a lot of time, $$, mistakes and reworking. @flintknapper and @alia176 stand out in my mind though I'm sure there were a number...

forum.ih8mud.com

You don't have to replace all of the parts covered in the above guide but if any are suspect I would replace them in an effort to do this once and then be done with it.

 

[RiverCityDave]

THIS is a USEFUL thread. The one directly above my reply. He covers pretty much everything about the 80 AC system.

 

[booradley]

Not sure where you are on all of this but I put together the guide below when I updated the AC on my 80 a few years ago. The thread below includes parts and material prices as well as information on where to source the few specialty tools you need and how to perform all work. Since you can get the specialty tools for free essentially your most economical option is going to be to do this yourself if you are capable.

FZJ80, R134A Air Conditioning System Rebuild How To

Thanks to the contributions of many very knowledgeable ih8mud contributors I was able to refresh the AC on my 1997 FZ 80. A few of those contributors surely saved me a lot of time, $$, mistakes and reworking. @flintknapper and @alia176 stand out in my mind though I'm sure there were a number...

forum.ih8mud.com

You don't have to replace all of the parts covered in the above guide but if any are suspect I would replace them in an effort to do this once and then be done with it.

Thanks, yes I’ve read through that one and several others. I’m about to get into it this weekend. Thanks for the assist.

 

[RiverCityDave]

Thanks, yes I’ve read through that one and several others. I’m about to get into it this weekend. Thanks for the assist.

One thing he points out in that thread that it is really important is that the compressor probably comes with oil in it. He also points out that you need to drain it, and replace it. You'll hear people always argue that, but I come down firmly on the side of draining and replacing. All the art on the box says "Pre-Filled" blah blah. I have always drained and replaced on import cars, and last year I replaced the compressor on my wife's Buick; however, in the interest of expediency, I skipped draining it, as I thought, "Hell, it's probably fine". Yeah, well, it wasn't. It started making noise straight away, and I ended up replacing the damned thing again. Thankfully not so hard on the Enclave, but still. I knew better, broke my rule, and paid for it.