AC Compressor & Desiccant pack on Sienna

[JZiggy]

Hey guys,

Hoping ya'll can give me a sanity check on an AC service project I'm planning for the 2012 Sienna with 2.7L 1AR-FE. The compressor has an internal leak making it perform poorly but it's not losing charge.

My main question is regarding how much PAG oil to include back into the system and how to do it properly.

I have a new Toyota OEM compressor. Instructions I've found say to drain the old compressor and the new compressor, measure amounts, and fill the new compressor with the same amount of oil that was in the old one.

I'm also going to replace the desiccant pack in the condenser. The FSM says to add 1.35oz of oil when replacing the condenser, but since I'm only replacing the filter I'm planning to just add 1oz. I will add this extra ounce to the new compressor before installing it.

Finally:
- Replace compressor and desiccant
- Vacuum down system for a couple hours
- Check that it holds vacuum before proceeding
- Charge up with correct full amount of R134a
- Confirm pressures are correct (approx 35psi LO and 230psi HI)

The system has also been evacuated and recharged once before during troubleshooting, so I'm unsure if that would cause more original PAG oil to escape and if I need to add more to compensate.

Any guidance or best practices, please share! Thank you.

 

[Chris142]

Always add more oil vs less.

When a shop evac and charges they normally add the amount of oil the machine removed,

Yes adding too much oil to the system can effect the cooling. An extra ounce or 2 won't effect it any.

Measure the amount you drain out of the old compressor. Add that back, add your ounce for the dessicant bag. Then add 1 extra ounce just cause.

 

[clinebarger]

Replace the condenser (Comes with a desiccant) & expansion valve after flushing the lines & evaporator. Then you can use total factory oil volume specifications.

IF the system is clean like you assume....You can get away with just swapping the compressor & balancing the oil.

 

[Marcozi]

Replace the dryer, always. Since a seal in the compressor leaked you can assume that compression oil gas leaked into the system. That means the entire system needs to be flushed to rid it of the oil. Also, add a UV dye just in case there are other leaks.

 

[JZiggy]

Replace the dryer, always. Since a seal in the compressor leaked you can assume that compression oil gas leaked into the system. That means the entire system needs to be flushed to rid it of the oil. Also, add a UV dye just in case there are other leaks.

Is "compression oil gas" different than the PAG oil that is already circulating within the entire AC system? I'm confused.

 

[Chris142]

Is "compression oil gas" different than the PAG oil that is already circulating within the entire AC system? I'm confused.

Ya ignore him. I been doing auto ac for 20+ years and have no idea what he said either.

 

[Nukeman7]

Hey guys,

Hoping ya'll can give me a sanity check on an AC service project I'm planning for the 2012 Sienna with 2.7L 1AR-FE. The compressor has an internal leak making it perform poorly but it's not losing charge.

My main question is regarding how much PAG oil to include back into the system and how to do it properly.

I have a new Toyota OEM compressor. Instructions I've found say to drain the old compressor and the new compressor, measure amounts, and fill the new compressor with the same amount of oil that was in the old one.

Always replace the old o-rings and use NYLOG Blue to lubricate/seal them. If the new parts did not come with new o-rings, either get a large variety pack or get them from Toyota (expensive) as the exact o-ring size is critical for a good seal. The green HNBR o-rings are supposedly more durable than black NBR o-rings for refrigeration systems.

I'm also going to replace the desiccant pack in the condenser. The FSM says to add 1.35oz of oil when replacing the condenser, but since I'm only replacing the filter I'm planning to just add 1oz. I will add this extra ounce to the new compressor before installing it.

I agree with @Chris142 that you should add a bit more PAG 46 oil than the total amount you drain out of the old removed components (i.e., the compressor & drier dessicant). I normally add 1 more ounce to the total drained since some residual oil will remain inside the old parts. PAG oil infused with fluorescent dye is preferred.

Finally:
- Replace compressor and desiccant

Put equal amounts of the oil in each port of the new compressor and manually rotate the compressor clutch plate 5-10 revolutions to distribute the oil. Reinstall the cleanliness plugs and stand the compressor upright with the clutch faced down for 30 minutes before installation to allow the oil to lube the shaft seal.

- Vacuum down system for a couple hours
- Check that it holds vacuum before proceeding

You should initially vacuum down the system for 10 minutes, isolate the system for 20 minutes and check for vacuum loss. If no leaks are found, then resume vacuuming for ~90 minutes.

- Charge up with correct full amount of R134a
- Confirm pressures are correct (approx 35psi LO and 230psi HI)

Here is the A/C temp-pressure chart you should use for general guidance if you are not weighing your refrigerant charge.

 

[JZiggy]

Always replace the old o-rings and use NYLOG Blue to lubricate/seal them. If the new parts did not come with new o-rings, either get a large variety pack or get them from Toyota (expensive) as the exact o-ring size is critical for a good seal. The green HNBR o-rings are supposedly more durable than black NBR o-rings for refrigeration systems.

I agree with @Chris142 that you should add a bit more PAG 46 oil than the total amount you drain out of the old removed components (i.e., the compressor & drier dessicant). I normally add 1 more ounce to the total drained since some residual oil will remain inside the old parts. PAG oil infused with fluorescent dye is preferred.

Put equal amounts of the oil in each port of the new compressor and manually rotate the compressor clutch plate 5-10 revolutions to distribute the oil. Reinstall the cleanliness plugs and stand the compressor upright with the clutch faced down for 30 minutes before installation to allow the oil to lube the shaft seal.

You should initially vacuum down the system for 10 minutes, isolate the system for 20 minutes and check for vacuum loss. If no leaks are found, then resume vacuuming for ~90 minutes.

Here is the A/C temp-pressure chart you should use for general guidance if you are not weighing your refrigerant charge.
View attachment 300825

Amazing! Thank you so much. Later this week I'll digest this carefully and come back with questions.

I will indeed be adding refrigerant via scale, and then verifying pressures.

 

[JZiggy]

Amazing! Thank you so much. Later this week I'll digest this carefully and come back with questions.

I will indeed be adding refrigerant via scale, and then verifying pressures.

@Nukeman7 Do you know offhand if this is the drain hole for the oil (marked 8.8)?

Should I fill the compressor with the total amount of PAG oil I want to add to the system? Amount in old compressor + 1oz for desiccant + 1oz for good measure, all into the two ports like you stated?

Thanks

 

[Nukeman7]

I believe it is an oil drain plug similar to the screen capture below.

Watch the "Lesson #12: How to Replace Compressor" video by The Old Mecanico Show on YouTube. I can't link it here on BITOG because one slide has mild profanity in it. He prefers to fill all of the oil into the large (suction) orifice.

 

[JZiggy]

I believe it is an oil drain plug similar to the screen capture below.
View attachment 300923

Watch the "Lesson #12: How to Replace Compressor" video by The Old Mecanico Show on YouTube. I can't link it here on BITOG because one slide has mild profanity in it. He prefers to fill all of the oil into the large (suction) orifice.

Thanks for the video. Great explanation. Wish I had college professors as good as that guy!!

 

[JZiggy]

Drained the new OEM compressor, turning the shaft a good bit and giving it some opportunities to run down at different angles for a while. All I can get out is 50 mL, ~1.5oz. Doesn't seem like very much given the FSM says the compressor should have 4.5 oz in it.

 

[Nukeman7]

Drained the new OEM compressor, turning the shaft a good bit and giving it some opportunities to run down at different angles for a while. All I can get out is 50 mL, ~1.5oz. Doesn't seem like very much given the FSM says the compressor should have 4.5 oz in it.

Trust your eyes over the FSM.

The FSM amount of 4.5 oz. is contingent on the compressor being completely dry (when the Sienna was initially built) and contains no PAG oil at all. Once you operate the A/C system, most of the 4.5 oz. gets distributed throughout the rest of the system (e.g., condenser, evaporator, hoses, drier, TXV), so less oil remains in the used compressor.

For example, I replaced a DENSO compressor in a 2010 Honda Accord 2 weeks ago. While the FSM said to load 4 ounces of PAG 46, I was only able to drain out 1.4 oz. from the bad compressor. As such, I drained the 3 oz. pre-filled in the new compressor, and re-installed 2.4 oz. The compressor and A/C system has never worked better.

 

[JZiggy]

Thank you! As a newbie, quantitative anecdotes like this are helpful for me to get my bearings.

Will owe you a beer when this project is complete!

 

[JZiggy]

New compressor had 50 mL, old one had 30 mL

Using the guidance I received here and from Old Mechanico I added a total of 90 mL of new PAG to the system. 50mL went into the new compressor via suction port, 40mL went into the high pressure line.

 

[Nukeman7]

New compressor had 50 mL, old one had 30 mL

Using the guidance I received here and from Old Mechanico I added a total of 90 mL of new PAG to the system. 50mL went into the new compressor via suction port, 40mL went into the high pressure line.

View attachment 302171View attachment 302172

No!!! That is too much oil!!!

If you drained 30 ml out of the old compressor and 50 ml out of the new compressor, you should add back in 30 ml + an additional ~10 ml for a total of 40 ml, not 90 ml. Your system will not cool correctly if you add that much oil. See this previous BITOG thread.

 

[JZiggy]

No!!! That is too much oil!!!

If you drained 30 ml out of the old compressor and 50 ml out of the new compressor, you should add back in 30 ml + an additional ~10 ml for a total of 40 ml, not 90 ml. Your system will not cool correctly if you add that much oil.

Thanks for the quick response. Do I not need an extra ounce (30mL) for replacing the desiccant pack as well? I am not, however, replacing the condenser, just the pack and filter.

 

[Nukeman7]

Thanks for the quick response. Do I not need an extra ounce (30mL) for replacing the desiccant pack as well? I am not, however, replacing the condenser, just the pack and filter.

It depends on how much oil you can drain from the old dessicant pack. If the FSM says 30 ml. for the dessicant pack, that is what I would add.

p.s., I forgot you were also replacing the dessicant. Is the actual dessicant "pack" removable from the drier on a Sienna? Or are you replacing the drier canister assembly containing the dessicant beads?

 

[JZiggy]

It depends on how much oil you can drain from the old dessicant pack. If the FSM says 30 MLS for the dessicant pack, that is what I would add.

p.s., Is the actual dessicant pack removable from the drier on a Sienna? Or are you replacing the drier canister assembly containing the dessicant beads?

It's a pack as pictured, and goes up through the bottom side of the condenser.

FSM states like 40mL for replacing the whole condenser, and does not specify the filter separately. I figured I would round down.

I was able to drain 30mL back out of the high pressure line, so now there's a total of 60mL of fresh PAG oil. I can pull the compressor back out and drain a bit more. What do you think?

 

[JZiggy]

Here's the old desiccant pack. It's hard to imagine that there are more than a few mL in this thing.