AC Recharge

[54Rich]

My 87 T has had the AC open to air for an undetermined amount of time. The hose was broken at the compressor and the unit was disconnected. I have had the line repaired. I have bought a new dryer and oriface.

My question is:

1) What type of compressor oil is used?

2) How much should I add to the system? Where do I add it?

Thanks,

Rich

 

[BlackBandit]

You need to get the system vacuumed to boil out any moisture. This is key to cold A/C. Then you add the oil/coolant through the low pressure fitting. The oil needed is determined by the type of refrigerant being used.

 

[54Rich]

You need to get the system vacuumed to boil out any moisture. This is key to cold A/C. Then you add the oil/coolant through the low pressure fitting. The oil needed is determined by the type of refrigerant being used.

Thanks, Any idea of how much I should add?

So could I just put the oil in the dryer, install it, vacuum it down, make sure it holds, then charge it?

Rich

 

[BlackBandit]

The amount of refrigerant depends on the type used as well. I don't have a ton of experience with A/C and I don't have a manual here so make sure you verify this, but if you're using 134a I think you can install everything, get it vacuumed, and then add oil and coolant through the low pressure port on the hard line. A search on this might yield some good results as well.

 

[54Rich]

The amount of refrigerant depends on the type used as well. I don't have a ton of experience with A/C and I don't have a manual here so make sure you verify this, but if you're using 134a I think you can install everything, get it vacuumed, and then add oil and coolant through the low pressure port on the hard line. A search on this might yield some good results as well.

I've searched and came up empty. I think that system is supposed to hold 8 oz of oil and since I can't assume any amount is in it, I wonder if I can add another 8 oz? There has to be a min - max level. This is my big question of the day.

Thanks for you help.

Rich

 

[turbojimmy]

I've searched and came up empty. I think that system is supposed to hold 8 oz of oil and since I can't assume any amount is in it, I wonder if I can add another 8 oz? There has to be a min - max level. This is my big question of the day.

Thanks for you help.

Rich

If memory serves, the manual for my R134a conversion kit said to drain the oil from the compressor, measure how much came out and add that much PAG oil (oil compatible with R134a). This assumes, of course, that you're converting to R134a.

Jim

 

[David65]

Heater and Air Conditioning

 

[54Rich]

If memory serves, the manual for my R134a conversion kit said to drain the oil from the compressor, measure how much came out and add that much PAG oil (oil compatible with R134a). This assumes, of course, that you're converting to R134a.

Jim

I guess I'll pull the compressor and see what's in it. Half of what I read says Ester Oil, the other half says PAG oil

I think Ester is what it came with it. Since I'm going to HG12, that's what I'll use.

Thanks,

Rich

 

[54Rich]

Update

I sent a message out to an AC supplier. Here is there reply:

I believe the system should be flushed at this point. Please see the
comments from FJC. I would also suggest that you contact one of our
distributors in the area for the oil capacity info. A good place to start
would be Automotive Cooling Products at . They have everything
in stock that you will need.
Best,

>
>Doug,
>I cannot find any information about a Buick Grand National.
>
>Yes the system should be flushed to remove any contanimation.
>
>You can use Ester or Universal PAG
>
>If you are not replacing the compressor you can add the oil to the
>accumulator. If the car does not have an accumulator you will need to add
>it to the entire system.
>
>The amount of oil depends on how much you have lost. The only way to
>determin the exact amount is to flush the system and put the exact amount
>the system calls for.
>

So looks like I can use either oil in the system, but I need to flush the system. So two additonal questions:

1) Anyone know how to flush an AC system system?

2) If someone has access to a service manual, could you please list the oil capacity for the AC. I'm going to try to find out more information locally, I'll post my findings.

Thanks,

Rich

 

[83ttypecooled]

Hi,
Ester will be fine, if you are using 134a.Personally, I prefer rb276, which comes with it's oil in suspension. For conversion use only,it keeps the head pressure down, which is what tears up our compressors.As far as oil volume, I guarantee you have a few ounces of the original still in the condenser,and the compressor probably has a couple, too.The total system holds 8 to 11 ounces. Put 2 in the accumulator,and add an oil charge or two, and you should be good to go.
Regarding flushing, It's a great idea, if you have the proper equipment. I have been unhappy with my flushing attempts, because I think it leaves agents in the system, regardless of how much air you blow in there. So, the cure might be as bad as the disease. Nowadays, when I am dealing with catastrophic compressor failure,I sell a condensor, as part of the job. They are reasonable, and good insurance.
Good luck with your project!