All new A/C system, verify PAG oil amount (1 Viewer)

[jomichael]

Replaced the following on my 91 FJ80 A/C system: condenser, dryer, evaporator, expansion valve, and compressor.

FSM says the compressor needs 220 cc or 7.439 fl oz to fill compressor.

FSM also states that when replacing following to add the amount shown below to the compressor. My question is, is this in addition to the 7.439 when replacing the compressor?
condenser add 1.4 -1.7 fl oz
evaporator add 1.4 - 1.7 fl oz
dryer add .7 fl oz

So I should add a total of 11.53 fl oz to the compressor before I take it down to the a/c shop to fill it up with 134R, is that correct? I want to get this right the first time.

 

[flintknapper]

Replaced the following on my 91 FJ80 A/C system: condenser, dryer, evaporator, expansion valve, and compressor.

FSM says the compressor needs 220 cc or 7.439 fl oz to fill compressor.

FSM also states that when replacing following to add the amount shown below to the compressor. My question is, is this in addition to the 7.439 when replacing the compressor?
condenser add 1.4 -1.7 fl oz
evaporator add 1.4 - 1.7 fl oz
dryer add .7 fl oz

So I should add a total of 11.53 fl oz to the compressor before I take it down to the a/c shop to fill it up with 134R, is that correct? I want to get this right the first time.

NO.....

New system will take about 8oz, TOTAL.

The instructions to add amounts to the components other than the compressor are for when they are being replaced as individual items.

In other words....if at some future point you needed to replace the drier, you would add the .7 fl oz. that it normally holds.

BUT....it would have been ideal if you had put about 4 ozs in the compressor and the remaining amounts in the respective parts before installing them. That way you have oil circulating just as soon as the compressor comes on line. But simply putting 8 ozs in the system (compressor) will work, it will just take longer to be distributed. The oil is carried through the system by the refrigerant.

 

[jomichael]

NO.....

New system will take about 8oz, TOTAL.

The instructions to add amounts to the components other than the compressor are for when they are being replaced as individual items.

In other words....if at some future point you needed to replace the drier, you would add the .7 fl oz. that it normally holds.

BUT....it would have been ideal if you had put about 4 ozs in the compressor and the remaining amounts in the respective parts before installing them. That way you have oil circulating just as soon as the compressor comes on line. But simply putting 8 ozs in the system (compressor) will work, it will just take longer to be distributed. The oil is carried through the system by the refrigerant.

Thank you so much, I felt there was a miscalculation going on. I can add some oil to the dryer and condenser, but there is no way I'm pulling out that darn evaporator again! I can even add some oil to the new rubber lines as I am having those rebuilt as well, does that work?

So, 8 fl oz total, and distribute half of it in the compressor and the rest in the dryer, condenser and lines?

 

[flintknapper]

Thank you so much, I felt there was a miscalculation going on. I can add some oil to the dryer and condenser, but there is no way I'm pulling out that darn evaporator again! I can even add some oil to the new rubber lines as I am having those rebuilt as well, does that work?

So, 8 fl oz total, and distribute half of it in the compressor and the rest in the dryer, condenser and lines?

Exactly right. You are well on your way.

Make sure to use new Orings and lubricate them with mineral oil (NOT PAG). Or if you can find a bottle of Nylog...use that. We don't want leaks.

Then have a shop pull a deep vacuum on it and charge with R134a refrigerant. If your old system was R12 then the new system will take a bit less R134a than the sticker on your vehicle says. But any shop that knows what they are doing should be able to just watch the high and low side pressures and get you nice, cold air.

If you have any questions, or issues with it, just let us know. There are several knowledgeable people here who can help.

 

[jomichael]

Exactly right. You are well on your way.

Make sure to use new Orings and lubricate them with mineral oil (NOT PAG). Or if you can find a bottle of Nylog...use that. We don't want leaks.

Then have a shop pull a deep vacuum on it and charge with R134a refrigerant. If your old system was R12 then the new system will take a bit less R134a than the sticker on your vehicle says. But any shop that knows what they are doing should be able to just watch the high and low side pressures and get you nice, cold air.

If you have any questions, or issues with it, just let us know. There are several knowledgeable people here who can help.

I noted that you said to lubricate the o-rings with mineral oil, not PAG oil. Yet the Toyota retro fit instructions say: "Apply a few drops of specified PAG compressor oil to O–ring fittings before tightening." Which is what I did, the o-rings are green o-rings. Hope everything will be ok or should I tear it apart, clean em up and use mineral oil? I also noticed that my connectors still have the black o-ring in there, yet I do not have the right size green o-ring replacement, is that an issue?

Appreciate all your expertise!

 

[jomichael]

I noted that you said to lubricate the o-rings with mineral oil, not PAG oil. Yet the Toyota retro fit instructions say: "Apply a few drops of specified PAG compressor oil to O–ring fittings before tightening." Which is what I did, the o-rings are green o-rings. Hope everything will be ok or should I tear it apart, clean em up and use mineral oil? I also noticed that my connectors still have the black o-ring in there, yet I do not have the right size green o-ring replacement, is that an issue?

Appreciate all your expertise!

Ugh, I did some research and the consensus is to use mineral oil not PAG. So, I will take apart the connections I have access to and clean up the o-rings and re lube with mineral oil. I will contemplate removing the evaporator to do the same for the expansion valve o-rings, though that was a pain in the a$$. Are we talking months before a leak could start or years? It's these little things that always get ya!

 

[flintknapper]

I noted that you said to lubricate the o-rings with mineral oil, not PAG oil. Yet the Toyota retro fit instructions say: "Apply a few drops of specified PAG compressor oil to O–ring fittings before tightening." Which is what I did, the o-rings are green o-rings. Hope everything will be ok or should I tear it apart, clean em up and use mineral oil? I also noticed that my connectors still have the black o-ring in there, yet I do not have the right size green o-ring replacement, is that an issue?

Appreciate all your expertise!

Despite what the instructions say.....I don't like to use PAG to lubricate the Orings. Not because the two aren't compatible but because PAG oil is highly hygroscopic (attracts moisture and does so quickly)...so when you join the two parts you trap a small amount the oil between the mating surfaces.
PAG oil and moisture (over time and with heat) creates an acid. When you see pitted and leaking aluminum fittings...this is generally what happened. It won't occur for a long time....so don't pull everything apart now. I just like to have folks start out using the best procedures. And please understand that the FSM (Toyota Instructions) are to be used as fairly accurate guidelines, but have their fair share of mistakes and unnecessary procedures.

The color of your O-rings makes no difference, modern A/C O-rings can be either color and still be the same material....BUT the size does need to be correct (or very close).

 

[jomichael]

Despite what the instructions say.....I don't like to use PAG to lubricate the Orings. Not because the two aren't compatible but because PAG oil is highly hygroscopic (attracts moisture and does so quickly)...so when you join the two parts you trap a small amount the oil between the mating surfaces.
PAG oil and moisture (over time and with heat) creates an acid. When you see pitted and leaking aluminum fittings...this is generally what happened. It won't occur for a long time....so don't pull everything apart now. I just like to have folks start out using the best procedures. And please understand that the FSM (Toyota Instructions) are to be used as fairly accurate guidelines, but have their fair share of mistakes and unnecessary procedures.

The color of your O-rings makes no difference, modern A/C O-rings can be either color and still be the same material....BUT the size does need to be correct (or very close).

Thanks for being so detailed, I really enjoy learning anything I can from people who are knowledgeable on the subject. I will clean up all accessible joints. At least I will know where to look (i.e. expansion valve) if things go south in a few years! Much appreciated.

 

[flintknapper]

Thanks for being so detailed, I really enjoy learning anything I can from people who are knowledgeable on the subject. I will clean up all accessible joints. At least I will know where to look (i.e. expansion valve) if things go south in a few years! Much appreciated.

Happy to help anyone who displays a good attitude and perseverance. You have both.

 

[jomichael]

Happy to help anyone who displays a good attitude and perseverance. You have both.

Hope I can get more of your advice flintknapper! Just had a friends shop fill the system with 134, everything holds, the A/C clutch engages but no cold air. They are suspecting a door is not opening under the dash. I did some research and there is a mixer valve under the hood and an HVAC door actuator under the dash. How would you go about diagnosing this? The mixer valve is kinda cheap ($44) at autozone, while the HVAC actuator is $200 from Toyota. The heater works ok, not super hot, but it does blow out when on. If I do have to buy the HVAC actuator, can that be installed without evacuating the a/c system and ripping apart the dash?

Any help you can provide is appreciated!

 

[flintknapper]

Hope I can get more of your advice flintknapper! Just had a friends shop fill the system with 134, everything holds, the A/C clutch engages but no cold air. They are suspecting a door is not opening under the dash. I did some research and there is a mixer valve under the hood and an HVAC door actuator under the dash. How would you go about diagnosing this? The mixer valve is kinda cheap ($44) at autozone, while the HVAC actuator is $200 from Toyota. The heater works ok, not super hot, but it does blow out when on. If I do have to buy the HVAC actuator, can that be installed without evacuating the a/c system and ripping apart the dash?

Any help you can provide is appreciated!

I'm not very familiar with what is under the dash area, not ever having had to go into one. But....yes replacement of any parts there (blend door, actuator) will NOT require evacuating the system. I can't speak to how involved getting to the components might be sorry.

I would first make note of which positions work (or don't work) with respect to the vents on both heat and A/C.

You Heater Valve (Located on firewall above rear of valve cover) should be easy to check. Just move the lever inside fully off and on and look at the valve to see you have corresponding movement (stop to stop) under the hood.

Turn you blower on high and check each and every position for air flow and let us know what you find. Select 'recirculate' for the AC setting.

Once we see what does or doesn't work....it should give us some direction as to whether you have flaps not operating, blend door, actuator, etc....

 

[jomichael]

I'm not very familiar with what is under the dash area, not ever having had to go into one. But....yes replacement of any parts there (blend door, actuator) will NOT require evacuating the system. I can't speak to how involved getting to the components might be sorry.

I would first make note of which positions work (or don't work) with respect to the vents on both heat and A/C.

You Heater Valve (Located on firewall above rear of valve cover) should be easy to check. Just move the lever inside fully off and on and look at the valve to see you have corresponding movement (stop to stop) under the hood.

Turn you blower on high and check each and every position for air flow and let us know what you find. Select 'recirculate' for the AC setting.

Once we see what does or doesn't work....it should give us some direction as to whether you have flaps not operating, blend door, actuator, etc....

View attachment 2675021

The mixer was out of adjustment, after adjustment the A/C is pretty cold. Not like a new car of course. I ordered a condenser fan from landcruiserphil, I bet that will cool it off even more here in Texas!

Thanks for all your help, it's nice to have A/C in my rig!!!

 

[flintknapper]

The mixer was out of adjustment, after adjustment the A/C is pretty cold. Not like a new car of course. I ordered a condenser fan from landcruiserphil, I bet that will cool it off even more here in Texas!

Thanks for all your help, it's nice to have A/C in my rig!!!

The condenser fan helps at low speed (Stop lights, at idle, backed up traffic). Yes, we need every bit of help we can get in the Texas Heat.