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.