Mercedes AC - York compressor torque specs
by Patryk Rebisz

Air conditioning on your w114 280 was powered by a chunky piece of metal - York 210 compressor. Those can be bought as rebuilds (not recommended as rebuild quality isn't great) or brand new units that were converted for R134a. Some people will recommend to swap out the compressor for Sanden but be warned that you might have to deal with cooling fan not clearing the compressor's clutch. So York it is...

The compressor will need service valves - quality ones are not exactly easy to come by. The silver-looking ones are good - but do NOT get the ones that have yellowish plating that you run into easily when searching for those online - they are terrible and will break when you try to tighten them down to the recommended specs. The valves come in a variety of sizes and layouts so be sure to get the correct ones - don't ask me how I know this...

You will need to find a clutch that matches with your water pump pulley. This is more difficult then one would anticipat because those come in a variety of circumferences, distance of v-belt grove from the compressor plate and the v-belt thickness itself. Even simple thing like if the clutch mechanism is inside the pulley or not makes a difference potentially causing difficulty with clearing your cooling fan - this M110 engine is tight! Moreover, you don't want clutch that's too small in diameter as this will strain the engine even more than this powerful compressor already is doing.

Have a look at the pic below. The clutch on the left had its v-belt grove too far from the compressor plate. The middle clutch is too small in diameter AND those few MM of extra height in clutch mechanism caused the fan clearance issues. The one on the right was perfect but the bottom v-belt grove had to be cut off to clear engine parts:

Beside the compressor, you will most likely also need to buy a new dryer unit and possibly replace the hoses and the expansion valve. I took my chances and left hoses and expansion valve as it was knowing that the hoses will let the R134r escape slowly because of particle size difference.

Assuming that your fan and switches are working (thus switching the AC on), you should have no problems rebuilding your AC. What might be hard to find is proper torque specs and here is where this handy cheat-sheet comes in. The torques are specific for York compressor attached to Mercedes engine but i suspect many others will have similar.

York compressor torque specs for Mercedes engine:
- service valve to compressor - 40-45 Nm (30 - 33ft lb)
- hose to service valve (with cooper washer) - 60 Nm (44 ft lb), (without) - 70 Nm (52 ft lb)
- hose to condenser (with cooper washer) - 45 Nm (33 ft lb), (without) - 55 Nm (41 ft lb)
- hose to receiver dryer (with cooper washer) - 45 Nm (33 ft lb), (without) - 55 Nm (41 ft lb)
- oil check plug - 7Nm (5 ft lb)
- fastening plate to compressor 30 Nm (22 ft lb)
- mounting bracket of compressor to engine - 30 Nm (22 ft lb)
- holder for tension roller on cylinder head - 30 Nm (22 ft lb)
- clutch assembly to compressor 13 Nm (10 ft lb)
- clutch to compressor 20-26 Nm (14 - 20 ft lb)

Oil (in CC) -PAG for A135r and Mineral for r12: 180 (min) - 240 (normal) - 300 (max).

Hope it was helpful!