AC Compressor, Dryer & Expansion Valve Install

[k-huevo]

Compressor clutch failures are not uncommon in our MINIs; unfortunately, the clutch is not available as a new OEM part. When replacing the AC compressor it is recommended to replace the receiver dryer also; in my case I installed a new expansion valve additionally in hopes of correcting pre-failure poor cooling performance.

Besides the tools needed to remove the bumper cover & bumper, and put the radiator support in service mode, the only other DIY tools required are a universal adaptor, T-20 Torx, 6mm Allen wrench, and 4mm Allen socket.

Have the refrigerant recovered by a professional before opening the system; the high & low refrigerant pipe ports are located on the left side of the engine bay. In this photo there is bright colored dye evident around one of the ports. I had dye injected on a previous refrigerant service visit to show any leaks in the system.


Drive the front of the vehicle on ramps or lift onto stands, remove the bumper cover and bumper.


I highly recommend reviewing the install procedure in the Bentley Service Manual before attempting these replacements, but there are a few tips I would add. Save the dryer replacement for the last step and keep the protective cover attached until the last moment to prevent saturation from moisture in the air, leave the compressor plugs in place (compressor lube inside) during the install and remove just before inserting the refrigerant pipes, wrap open ends of the refrigerant pipes to prevent moisture ingress here as well.

Put the radiator support in service mode, or remove to allow access to the compressor.


Remove tension from the belt and move the belt out of the way, unplug AC clutch pick-up connector, use a 6mm Allen wrench to disconnect the refrigerant pipes.


Some fluid may be in the lower line.


Remove the right and left upper 13mm bolts.



Support the compressor and remove the bottom 13mm bolt.


Remove old O-rings, install new O-rings, and lubricate.



When installing the new compressor screw in the upper two bolts, torque to 18 ft-lb, screw the bottom bolt in and torque to 18 ft-lb also, the mount sleeves will self align when tightened.

Replace the refrigerant pipe O-rings and lubricate, insert and secure with the new 6mm bolts, torque to 15 ft-lb or firm hand tight. Plug the pick-up connector back in, route the belt around the AC pulley, and release the tensioner.

If AC performance was adequate before a compressor failure, and compressor failure did not contaminate the system with metal debris, replacing the expansion valve is probably not needed. Replacing the EV was the most frustrating install I’ve ever performed on my MINI, so unless the installer possesses small hands and X-Ray vision, I recommend avoiding an EV install (or pay to have it done).

The EV adaptor block is located on the firewall just right of center (facing the vehicle); the air box is removed to access it.



A universal socket adaptor will be helpful here, as well as a mirror to help with guidance for bolt location. The refrigerant pipes are secured by 10mm hex bolts, and the adaptor block to EV with 4mm Allen bolts.


The expansion valve is located under the dash on the driver’s side. Unclip the lower dash trim, unscrew the three T-20 screws from the right foot well cover; the upper rear screw is difficult to R&R and the upper right screw is not easily seen.



I disconnected the throttle pedal to allow easier panel removal but it is not necessary. Remove the EV pipe’s threaded clamping plate by moving upward from the closest pipe then pulling out.



Replace and lubricate O-rings, press the EV on the refrigerant pipes; from the firewall insert the adaptor block, screw the 4mm Allen mounting bolts in and tighten (53 in-lb). Replace the O-rings on the engine compartment side refrigerant pipes and secure the 10mm bolts (6 ft-lb). Re-install the air box, foot well heating & AC cover, and throttle pedal if removed.

The dryer is located on the left side of the condenser (facing the engine), it is held in place by a 10mm and clamped with a T-20 Torx, also remove the 10mm bolt on the right side of the condenser for a little more wiggle room.



Unscrew the dryer using the 13mm hex on top.


The old & new dyers side by side; be sure to lubricate the dryer’s O-rings before reinstalling and use the supplied new rubber gasket. Screw the new dryer in and torque to 10 ft-lb. Attach the replacement support clamp, tighten the T-20 clamping bolt, and screw the two condenser bolts back in.



Push the radiator support back in place; attach the bumper and bumper cover.

Do not run the AC until refrigerant is replaced; when operating the compressor for the first time run the engine at idle speed for two minutes before raising revs.