How to Replace a Hydroboost Brake Booster on a 1997 Chevy K3500 Truck

by Russell Wood

A 1997 Chevrolet K3500 truck is a heavy-duty truck with dual rear wheels. These trucks carry heavy loads, and as a result, require more braking power than the average truck. To make this happen, the truck uses a hydraulic brake booster instead of a vacuum brake booster, which is called a hydroboost. If your hydroboost unit has failed, then you can replace it with a new one in a few hours with a few tools.

Park the truck and engage the emergency brake. Pump the brake pedal five times with your foot. Pop the hood on the truck. Unbolt the master cylinder from the hydroboost with an open-end wrench and pull it off of the hydroboost. Label the lines leading into the hydroboost with a permanent marker and masking tape in such a way that you will be able to figure out where the lines go when you reassemble the assembly.

Remove the lines running into the hydroboost with a line wrench. Move to the underside of the dash. Remove the clip securing the hydroboost linkage to the brake pedal with your hands. Unbolt the hydroboost from the firewall with the 3/8-inch ratchet and socket.

Pull the hydroboost off of the firewall. Install the replacement hydroboost on the firewall with the 3/8-inch ratchet and socket. Install the replacement hydroboost linkage to the brake pedal with the factory clip. Install the lines onto the replacement hydrobooster with a line wrench.

Install the master cylinder onto the hydroboost with an open-end wrench. Open the power steering pump cap on the driver's side of the engine and fill it up with additional power steering fluid, if necessary.

Lift the front of the K3500 with the jack and put jack stands under the frame. Start the engine. Turn the steering wheel all the way to the right, then all the way to the left, a total of 10 cycles to bleed air out of the power steering system. Lower the truck off of the jack stands with the jack.

Items you will need


About the Author

Russell Wood is a writer and photographer who attended Arizona State University. He has been building custom cars and trucks since 1994, including several cover vehicles. In 2000 Wood started a career as a writer, and since then he has dedicated his business to writing and photographing cars and trucks, as well as helping people learn more about how vehicles work.