# X214 Compressor Walkthrough

By James Levin

Topic: Machines

[Open the interactive Jig](https://ask.jig.com/j/pTrRScH08KKG)

## Guide

### 1. Meet the X214

This chunky iron block is an X214 compressor, the heart of a refrigeration unit on a truck or trailer\. Its job is to help keep cargo cold on the road\. Drag anywhere to turn it and look around\.

This one is remanufactured: rebuilt with new wear parts and sold as an aftermarket, non\-Thermo King part\.

### 2. The outside, part by part

On top sits the cylinder head, held down by six bolts\. Below it are the cylinder block and the big crankcase\. A drive shaft pokes out of one side, a round end cover closes the other, and four feet bolt it down\.

The bare compressor weighs about 20 kilograms, or 45 pounds\.

### 3. Power comes in through the shaft

A belt from the engine or an electric motor turns this drive shaft\. The shaft is the only way power gets in\. Press the button to give it a spin and watch the brass key go round\.

Real compressors spin many times faster than this\. Everything here is slowed down so you can follow it\.

### 4. A look inside

Let's cut the castings in half\. The shaft is one piece with the crankshaft, which has two offset sections called cranks\. Connecting rods turn their circles into the up and down motion of two pistons\.

Each cylinder is 57 millimetres wide, and each piston travels 45 millimetres, about the width of a golf ball\.

### 5. Breathe in, squeeze, push out

Refrigerant is a fluid that boils easily\. As a piston moves down, it draws in cool, low\-pressure refrigerant gas, shown in blue\. As it rises, it squeezes the gas into a small space, which makes it hot, shown in orange\. Change the speed to watch the rhythm\.

In this model the two pistons take turns: while one breathes in, the other squeezes\.

### 6. Valves and the head

Between the cylinders and the head lies the valve plate\. Thin metal valves on it work like one\-way doors\. Squeezed gas pushes them open, flows into the head and leaves through the gas ports on its way to the rest of the system\.

The two cylinders together sweep about 228 cubic centimetres, close to a cup of gas, every turn of the shaft\.

### 7. Oil keeps it smooth

Metal rubbing on metal wears out fast, so oil waits in the sump at the bottom\. A small oil pump on the end of the crankshaft sends it to the bearings\. A shaft seal keeps oil and refrigerant from leaking out where the shaft leaves the case\.

The small window on the front, called a sight glass, lets a mechanic check the oil level\.

### 8. Part of a bigger loop

Hot, squeezed gas travels to the condenser, where it gives its heat to the outside air and turns to liquid\. An expansion valve lets the pressure drop, so the refrigerant boils in the evaporator and soaks up heat from the cargo\. Then the gas returns to be squeezed again\.

A compressor does not make cold\. It moves heat from inside the box to the outside\.

### 9. Ready to work again

Rebuilt compressors like this one give an old design a new life\. When you buy one, you pay a core charge, a deposit you get back when you return your old compressor so it can be rebuilt too\.

On the seller's page, this reman X214 was listed at 1,625 dollars plus a 500 dollar core charge\.