There are several different types of brake chambers that accomplish different tasks in different areas of the undercarriage of your truck. Knowing your rotochambers from your piggybacks will help you navigate to the right parts you need for your truck.
WHAT DO BRAKE CHAMBERS DO?
Before we get into all the specific types, let’s talk about what they have in common first. Each of the different types of brake chambers accomplishes the same basic thing: they transfer compressed air from the brake pedal and use to drive the chamber’s pushrod away from the chamber, which then enacts the brakes to start stopping your wheels from turning.
The pushrod is yoked to the S-cam or the camshaft which then turns to push the brake pads to the drum, slowing the vehicle down. Because we have different brakes and different moving areas in our undercarriage we need to stop in order to “stop” we have different chambers that accomplish different things.
SERVICE BRAKE CHAMBERS
These are your most basic types of chambers. There is a service chamber working for each wheel of your vehicle in some form or another. While service chambers are found incomplete brake chamber sets, you can also find them on truck and trailer applications in the steering and suspension.
All the service chambers really do on your vehicle is exactly what brake chambers are meant to do, which is to stop the vehicle when pressurized air is pushed through the chamber. It does this with the pushrod, its diaphragm, which is a rubber pad that seals the air from leaving the chamber, and lastly, the return spring, which pushes the chamber back to its original internal position after the air has made its way through.
The components of the service chamber can be fixed, serviced, or rebuilt by opening the chamber and replacing the parts.
PIGGYBACK BRAKE CHAMBERS
They don’t call it a piggyback chamber for no reason, the piggyback brake chamber sits connected to the service chamber, and acts as the chamber for the truck’s emergency brake chamber. Any emergency braking system or a regular parking brake will use the piggyback chamber.
The internal difference is that the piggyback has an extremely powerful spring. If air is not being supplied to the chamber, the spring launches the pushrod to stop the brakes. The piggyback chamber is always linked to a service chamber set, and you’ll only find it on a trailer and drive axels, never steering.
NOTE: DO NOT OPEN THE PIGGYBACK CHAMBER. DUE TO THE INTENSE FORCE OF THE SPRING, OPENING THE CHAMBER IS INCREDIBLY DANGEROUS.
COMPLETE SPRING BRAKE CHAMBERS
The Spring Brakes sometimes called Complete Brake Chambers are a combination of the service chamber and the piggyback chamber. These systems have both chambers built-in but rarely work at the same time with each other.
Because of a potential loss in control, spring brakes are often found on rear axles.
As we mentioned with the piggyback chamber, you should NEVER open and service this chamber, however, the service chamber side (the chamber on the pushrod side) you can open and update.
Lastly, we’ll talk to you about the outlier, which is used mostly for specialty heavy-duty vehicles and equipment. You’ll also see them on buses and other transportation equipment.
We are Custom Automotive Brake Master Cylinders Suppliers, You can search through our brake chambers here and all of our spring brake chambers and systems here.