Remove The Air Conditioning System on a Lotus Exige
Why remove the Air Conditioning (AC) from a Lotus?
- Installing a REV400 supercharger with front HEX from BOEfabrication.com
- Simplify and add lightness (-22 lbs)
- Race cars don't need AC
- Desire that fresh out of a sauna feel after a summer drive
Following this guide will provide guidance how to remove the AC system from a Lotus and optionally the AC lines running through the sills. The latter being non-reversible.
- Screwdrivers: Phillips and Flathead
- Sockets (mm): 6, 8, 10, 12
- Combination wrench (mm): 8, 10, 18, 19, 22, 23, 32, 35
- Flarenut wrench (mm): 18, 19, 22 [These are optional and will help save the AC lines]
- Stubby wrench (mm): 10mm
- Allen wrench: H4
- Hose Puller
- Putty Knife
Before beginning visit an automotive service center (any service center will do) to have the AC system evacuated (i.e. refrigerant removed). It is against the law in the United States to evacuate refrigerant to the atmosphere.
The AC service ports are located behind the passenger side intake on the rear clam and accessible by removing the cover (clam removal is not required).
Ensure both lines are depressurized before leaving the service center. You do not want to disconnect these lines while pressurized if you value your health and safety.
Quick Reference - AC and heating system
This is here as a quick reference section how the Lotus AC and heating system is designed.
Remove Front clam <link here>
Lift the Lotus onto jack stands or lift with a hydraulic lift.
Follow the instructions here to learn how to safely lift your Lotus Exige / Elise.
Remove AC receiver dryer
Gain access to the AC receiver dryer
- Use an 8mm socket to remove the two bolts (A) securing the fuse box. Take note the long bolt goes in the front closest to the radiator during reassembly. Don't loose the nylon spacers (white plastic tubes).
- Use a Phillips screw driver to remove the two machine screws (B) on the left side
- Use a 10mm ratcheting wrench to loosen (not remove) both nylon bolts (C) from the bottom side of the cowl mounts. The plastic cover below the fuse box will just slide out toward the radiator.
- Disconnect and move the wiring for the radiator fans out of the way and any other obstacles preventing clear access to the AC dryer.
- Remove ducting tube. Peel back the insulation at the top and pull toward the front of the car to disconnect the tube. Once the top is disconnected just lift it straight up to remove and set aside. This will need reinstalled if you plan to keep the heater.
Remove the Receiver Dryer
- Use 19mm and 18mm wrenches, use flare nut wrenches if possible, to disconnect both fittings on the top of the dryer. The 18mm wrench is used to hold the receiver (as shown below).
- Use a flat head screwdriver or 6mm socket to loosen the worm clamps (a.k.a hose clamp) securing the dryer in place.
- Lift the dryer out and remove.
- Remove the worm clamps by sliding up the bracket they are looped around.
Remove the receiver dryer bracket
- Use an 8mm socket to remove both bolts (A,B) securing the bracket to the frame and remove the bracket.
- Reinstall the bolt (B) which also secures the heater box bracket.
Remove AC Lines
If saving the hard lines to resell or reuse is not a priority you can save a lot of time by cutting them close to the nuts / fittings with a hacksaw. Depending how seized the fittings are you probably will end up doing this anyway.
Remove AC lines in the passenger side wheel well
- Use 22mm and 32mm wrenches to break loose the small diameter high pressure hard line (A) at the sill. Once the nut is easy to back out stop and leave it connected while you work on the other end. This will reduce the likelihood of damaging the hard line.
- Use 35mm and 32mm wrenches to break loose the large diameter low pressure hard line (B) at the sill and completely disconnect.
- Use 22mm and 19mm flare nut wrenches to break loose the front fitting (C). A standard wrench will work, be aware the nut and line are very soft and will round easily. If this happens just cut the hard line with a hacksaw. Completely disconnect and remove the hard line.
- Use two 19mm flare nut wrenches to disconnect the other front hard line (D) from the condenser.
Remove expansion valve
- Use an 8mm socket to remove the bolt and top clamp plate (A) securing both the small high pressure and larger low pressure hard lines.
- Lift up on the smalll hard line to remove from the expansion valve and disconnect the sensor (B) located on the line.
- Lift up on the large diameter hard line and remove.
- Remove the 2 clamp screws (C) with an H4 allen wrench from the expansion valve. Hold on to the bottom clamp plate beneath the expansion valve to prevent it from falling in to the abyss below.
- Hold the heater box with your left hand and using your right hand wiggle the expansion block off the AC lines beneath.
Remove OEM puller Fans
Take this from my other tutorial
MAKE SURE THE ENGINE IS COOL before proceeding!
Engine coolant can be very hot, pressurized, and cause burns if in contact with skin. Ensure the coolant tank is cool to the touch.
Drain and remove radiator coolant lines
Start with the drivers side and repeat for the passenger side.
- Have a bucket ready to capture 4 quarts of coolant from the hose once disconnected.
- Open the pressure cap on the coolant tank in the engine bay.
- Use a flat head screwdriver to release the hose clamp (A) securing the rubber or silicon hose to the hard line emerging from the chassis.
- Use a hose puller to break the seal and loosen the hose for removal.
- Slowly pull the hose off the hard line and allow the coolant to drain into the bucket.
Repeat process on the passenger side.
Optionally remove the security alarm siren with a 13mm socket after disconnecting the wiring harness. This will provide additional room and protect your hands trying to release the coolant hose.
- Use a flat head screwdriver to release the hose clamp securing the hose to the radiator on the driver side and remove.
- Use a flat head screwdriver to release the hose clamp securing the hose to the radiator on the passenger side and remove.
This may require cutting the shroud on the driver side as shown below to gain access to the hose clamp.
Use a 10mm stubby wrench to remove the 4 bolts (A, B) securing the top of the radiator to the rear mounting brackets
- Use a 10mm socket to remove the 4 bolts (A, B) securing the radiator to the shroud in the front.
- Remove the top spreader plates once the bolts are removed
- Use a putty knife to release the adhesive securing the foam surrounding the radiator to the shroud. Remove the foam and set aside as this will be reused.
- Slide the radiator and attached AC condenser out of the shroud. If this is too challenging follow the instructions below and do it with the shroud unsecured.
Optional: Loosen radiator shroud
This procedure is only needed if the radiator will not slide out of the shroud. Once complete reverse both steps to secure the shroud again once a radiator has been reinstalled.
Use an 8mm socket to remove the three bolts (A) securing the front of the shroud to the crash structure
Use a 10mm socket to remove the nut and bolt (A) securing the shroud to each side of the crash structure.
Use an 8mm wrench to remove the three bolts securing the rear of the shroud.
The driver's side needs a ratcheting wrench or open box end wrench to remove. Careful not to damage the brake lines
Remove AC Compressor
Disconnect rubber AC lines from rear hard lines
- Use a 23mm wrench to release the fitting (A) securing the small line and remove
- Use a 32mm wrench to release the fitting (B) securing the larger line and remove
- Disconnect the wiring harness connector (A)
- Use an 8mm stubby wrench to remove the bolt (B) securing the ground connection. A Phillips head screwdriver will also work, but the stubby wrench is easier.
Disconnect lines from the compressor
- Use a 10mm wrench to remove the single bolt on each hard line to release from the compressor
- Use a 12mm socket wrench to remove the three bolts securing the compressor to the block. You may need to rotate the alternator up to access the top most bolt.
- Remove the compressor and discard.
Optional: Remove hard lines in the passenger door sill
Remove the door sill cover inside the passenger door.
- Open the passenger side door.
- Remove the two Phillips screws (A) where the sill cover meets the front dash. Removal of the rubber pad is needed in the tiny storage area to access the screws.
- Pull up at the rear of the sill cover to break the adhesive tape (B) loose and remove.
- Set the sill cover aside and remove the double sided tape. It will be replaced later.
The following step will help ensure the door alarm sensor is not damaged in the process of removing the AC lines. It is not required, but a good idea.
Remove door alarm sensor
- Use a Phillips screwdriver to remove the screw (A)
- Pull the sensor out as shown
- Disconnect both electrical connectors. The purple wire connector pulls directly off, while the other has a locking mechanism (B). In the center use an awl or a punch to release it.
- Set the sensor aside somewhere safe.
- Pull the wiring harness up out of the sill and tape to the side out of your way.
Front foam block removal and line release.
- Remove the large foam block from inside the sill by folding the top of it back toward you, you'll have to roll it out a little ways until it won't come any more. Basically, it will only go so far until it pinches it self in there. Then pull up on the back portion (by the door alarm sensor), then repeat the cycle... you should have it out in a few cycles.
- Vacuum up all the wonderful dust and nasty that comes out with the foam block. You don't want to breath that stuff.
Release the fittings egress from the sill
- Remove both large nuts (A, B) from the the threaded tube joining the inner and outer hard lines.
In the event the fittings are seized don't be afraid to cut them off with a grinder and a metal cut off disc as shown below.
Cut the hard lines off inside the sill
- Use a Dremel with metal cut off wheel or equivalent device to cut the hard lines in half at the marked location. The lines will be pulled out the back of the sill (by the engine) make sure none of the 90 degree bend is left on the line.
- Remove the upper portion of the hard lines from the sills. They will not fit through the opening as-is, use both hands once free to bend the pipe to extract from the sill.
- Slap high quality duct tape over the two holes in the front sill where the hard lines used to egress.
Both hard lines contain trace amounts of lubrication oil (it's green and looks like antifreeze). Bend the tubes once cut up slightly and plug with a rag to prevent any leakage into the sill.
Cut both hard lines in the rear of the sill
- Use a Dremel with metal cut off wheel or equivalent to cut at the marked location on both hard lines
- Pull the short pieces up and remove from the car
- Pull the remaining hard lines running the length of the sill out towards the rear of the car. You'll have to bend them by hand as you pull creating a near circle by the time they are fully removed.
- Be ready for small amounts of lubrication oil to run out of the lines.
Congratulations!! You've simplified and added lightness.. Now enjoy a cold one while ordering a BOE REV400 with front Hex now that there is room for it :)
Refer to page 14 of Section PL in your Lotus manual