Onericali

Hey. So once you vacuum out all the R134, do you need to take the compressor out to flush it?

Do you add oil straight to the compressor, or just add it in the mixture after that?

I don't think you can flush the whole system unless you are ready to replace a few parts since flushing ruins filters.

I do have the DIY for taking the compressor out. (https://mbworld.org/forums/c-class-w...placement.html)

Eventually, I'm going to make a HECK of a DIY.

feliksim64

So, any replies where to add compressor oil?

Moviela

The oil circulates through the system with the R134a. There are flushing solvents that you pump through the system. You are supposed to capture the spent solvent with an expensive machine. Oil is added through the suction line when refilling the system. Be sure to add the correct amount of the correct oil.

feliksim64

Thanks for reply,
is there any possibility to fill oil through the filling valves without any machines?

Moviela

I have an oil tank that is inline with the suction hose. You need at least a vacuum pump to remove the air and moisture. At low vacuum (more than 29 in.) the air is all but gone and the water in the system boils at room temperature. It takes at least 40 minutes to pump that low. I always leave the gauge valves off for an hour to make sure there are no system leaks. I then connect the can to the center hose and open the can valve. I loosen the fitting on the center of the manifold and let a little gas escape to clear the air from the hose. With the oil in the tank, I slowly open the low side valve and allow the sauce to flow into the system. The pressure in the can coupled with the vacuum should be enough force to drag the oil into the system. I keep a sauce pan of 110F water to immerse the can. The can get quite cold and the increased temp forces the fluid from the can.

When the can is empty, start the engine and check that the high side produces enough pressure to keep the compressor engaged. If not, switch to a second can and continue letting it flow. When the compressor will run, continue to charge through the low side until the correct weight is installed. You do need an accurate scale for this. Over and under is not a good idea.

Check the evap temperature with an accurate thermometer and check that the low side pressure is correct for that temperature. Check that the high side pressure does not go over the specified maximum. Block the radiator and disconnect the fan and allow the pressure to rise and observe the high pressure switch cuts off the compressor. Keep an eye on the high side gauge to be sure it does not go crazy high.

Now you are not allowed to allow anything to escape to the air, or the EPA will make life miserable for you. That is why it is easier to do the grunt work yourself, and take it to a pro to be charged.