How to Remove a Bus A/C System

To remove a school bus AC system is no joke.  Before you take this on, really make sure you want to do it.

Are your AC units fully functioning?  Are they too bulky and that’s the only reason you’re taking them out?  If so, keep in mind that it is nice to have AC while you’re driving in hot places.  Having the original bus AC won’t interfere with a mini-split or roof-top unit you install for keeping you cool while parked.

If you are determined to take your bus’ original AC units out, know this…you can sell them!  No kidding.  Two perfectly functioning bus AC units can fetch $2000.  We had two Carrier units, one with a broken compressor and the other blowing cold.  We sold them both (compressors, tubes, and fans included) for $750, and that was a steal for the buyer.

So, if you are still ready to embark upon removing those old AC units, read on…

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Tools & Material Required to Remove a Bus AC:

• A socket wrench kit. Honestly, we recommend you just buy a kit like this right at the start of your conversion. You’ll use just about every tool in here, many times over. And this saves you from spending more money and time buying them piecemeal.
• An impact Driver (we got this impact driver/drill combo kit which served us well through the whole conversion!)
• Duct tape (the good stuff, don’t waste your money on the crappy stuff)
• Safety glasses and gloves
• Baggies and a sharpie
• A big piece of cardboard or a tarp to cushion your back when you are working under the bus
• A good friend who doesn’t mind getting really dirty

Step 1: Evacuate the freon

Find a company that can safely evacuate the freon from the AC system.  Your best bet is to call your local A/C repair service and ask them if they offer freon evacuation services.  If not, ask them who they can recommend.

Step 2: Dismount the inside evaporators (blower units)

We show the process of dismounting the inside units here in this video.  Essentially, it involves:

1. Removing the unit covering (keep those screws and screw caps in a clearly labelled baggie, so your buyer can re-assemble without a hassle).
2. You’ll see that the unit is fastened to the ceiling with four heavy-duty bolts.  Slowly lower the nuts on the bolts, bringing the units down with them.  You’ll need two people doing this at the same time (even better to have a third person holding and spotting the AC unit as it’s coming down).
3. When the bolts are out, carefully lower the unit to the floor.
4. Put the bolts into a baggie and mark them clearly, so the buyer knows what is what.

Step 3: Disconnect the hoses

1. It’s very important to wear safety gloves and glasses for this part!
2. Unscrew the hose clamps and fully disconnect the hoses, starting at the inside evaporators (the bulky pieces that are inside the bus).  THE FREON MUST BE EVACUATED FIRST!
3. Remove the hoses by following them from the inside evaporators through the floor/walls, to under the bus, to the engine compressors, and to the condensers.  You’ll have to work under the bus pulling the hoses out, so have something to lay on under there and wear safety glasses because a lot of dirt and gunk is going to fall all over your face when you’re pulling the hoses out.

Step 4: Remove the compressors from the engine

1. The compressors are bolted into the engine.  Remove them using a socket wrench and some serious muscle.
2. When the compressors come loose and are removed, the belt will slacken and you’ll be able to remove it.

Step 5: Remove the condensers and electrical board from underneath the bus

1. In our bus, the condensers were mounted up underneath the bus with a grid for the fans to access air through.  Unmount them just as you did the evaporators.
2. The electrical for our AC units was in a built-in box next to the battery box.  Remove the whole system completely.  If you’re unsure about any part of this step, it’s best to have someone with you who knows AC systems and/or electrical.  Just to be safe!  And if you’re curious about the details, give us a shout at [email protected] and we’ll walk you through it!

And that’s that!

Your old AC system is now gone (hopefully you got a few bucks for it), and you’re ready for the next step in your conversion (for us it was installing the propane tank).

And on that topic – good news! If you plan on mounting a propane tank under your bus like we did, the place where the condensers were may be just the spot.