AC compressor replacement

Hi guys,

The bearing on my compressor fried and the pulley is totally seized, so not driveable. I got a reman compressor, is it safe to just unhook the lines on the old one and swap in the new one?

I would have preferred to take it to a shop, but like I said, not driveable. The system is still charged because I had ice cold air right up until the end...

Any input greatly appreciated.

Thanks!

Ben

It is not safe. It's also a violation of federal law to vent refrigerant into the atmosphere in this manner.

I suggest you leave the lines connected but unbolt the old compressor. Try to simply move it out of the way enough to bolt in the reman so you can get the belt back on. Drive over to an AC shop and have them reclaim the old refrigerant.

You should replace the dryer/accumulator. You'll need to have the system flushed, evacuated, then refilled.

Cool thanks, I was just moving things around in there and was thinking this might be my best bet. I will see if I can make that work.

If not, do you have any idea if I can buy a vacuum to evacuate the system?

Ben

So if the system has been evacuated, can I replace the compressor and dryer, and then safely drive to a shop to have it recharged, as long as I don't turn the AC on?

Any comments, tips, help are much appreciated.

Thanks!

Ben

If it's been evacuated, and no more refrigerant is left in the system, yes you are safe to unhook the lines and replace the compressor and receiver/drier.

The system will need to be evacuated again before recharging, but the shop will do that.

Be sure you've got the proper amount of oil in the compressor! And also put an ounce or two in the receiver/drier before you hook everything back up.

You won't be able to accidentally run the AC on the way to the shop. The lack of pressure in the system (from lack of refrigerant) will activate the low pressure cut out switch that keeps the system from coming on. This is done to prevent damage to the compressor.

To further build on what people have stated here, you will also want to find a small beaker or graduated cylinder and pour the oil out of the old compressor to determine how much you will need to put back in the new compressor (also, find out of the new compressor is pre-loaded with PAG oil... some manufacturers load them with the factory full-charge of 6.1 oz, and over-oiling can kill the performance of the system). The oil distributes itself throughout the system, so you'll like see far less than 6.1 oz come out of your old compressor. The FSM has a chart pertaining to how much oil is typically lost when replacing various components (evap, condenser, etc.). For the compressor, they advise draining the old one and putting the same amount in the new one.

I've been obsessing over this crap for weeks now... I now have a living room full of AC system components and tools, and get to embark upon my complete system replacement this coming Tuesday. Should be a blast.

Awesome, thanks alot for all the tips!

My compressor came with 1.5 oz of oil in it. So to make sure I understand this correctly, I need to drain the old compressor and dryer, and then add the amount that comes out of them to each of the new components (minus the 1.5 oz in the new compressor already)?

Since the AC shouldnt be able to run and the compressor will just be "freewheeling", should I be good to drive for a few days before I get it vaccumed/recharged?

Again, thanks. It seems like finding info on this process is very hard to find, and I have seen tons of conflicting opinions on .

Ben

You are correct. It might be wise to dump the oil out of the new compressor in order to verify it actually has 1.5 oz in it. Then just measure out the appropriate amount of PAG oil and pour it into the compressor (it's usually a bad idea to add new oil anywhere else from what I understand).

You should indeed be fine waiting a couple days, as the compressor clutch will indeed be disengaged.

Right on, thanks!

I got the compressor out and draining, and everything is off except the AC dryer at the firewall...I took the compression clamp off, but how the heck do you get the tube out of there? It just spins freely, but I can't get it out. Do I need a tool for this?

The new dryer looks like it just has orings and a spring...not sure if the spring is what is holding me up.

Ben

Yep. Fuel line and AC line fittings require special tools to release the spring fitting (after removing the clamp). Most are plastic (even those made by Snap-On) and are super cheap, available at any auto parts store and Sears (hell, Walmart may even have them). Basically little collars that snap around the male end of the line and slide up into the female end, expanding the spring and releasing the connection.

anthrax323 said:

You are correct. It might be wise to dump the oil out of the new compressor in order to verify it actually has 1.5 oz in it. Then just measure out the appropriate amount of PAG oil and pour it into the compressor (it's usually a bad idea to add new oil anywhere else from what I understand).

You should indeed be fine waiting a couple days, as the compressor clutch will indeed be disengaged.

Click to expand...

I've always been told (and done so myself) to add an ounce or two to the components your replacing, depending on the size. For example, i'll add an ounce into the drier, and two ounces into the condenser when i'm replacing them.

As for the quick disconnect fittings, hit up Harbor Freight. They've got a really nice set of aluminum ones for very reasonable prices. Go ahead and get both sets (one is small sizes and one is bigger). They'll come in VERY handy for things like AC lines, fuel lines, and transmission lines.

UNCC_99XJ said:

I've always been told (and done so myself) to add an ounce or two to the components your replacing, depending on the size. For example, i'll add an ounce into the drier, and two ounces into the condenser when i'm replacing them.

As for the quick disconnect fittings, hit up Harbor Freight. They've got a really nice set of aluminum ones for very reasonable prices. Go ahead and get both sets (one is small sizes and one is bigger). They'll come in VERY handy for things like AC lines, fuel lines, and transmission lines.

Click to expand...

You are absolutely correct - the rule of thumb in that arena that I've been taught by several experts, however, is that you should put the PAG oil directly in the compressor *if* it is also being serviced/replaced (as the oil will distribute itself throughout the system from there). If the compressor isn't being touched, though, you can pour it straight into the component(s) being replaced. The FSM has a table listing the volumes of oil to be re-added for each component in the system (a nice little cheat sheet).