How To Adjust the Wilwood Drum Internal Parking Brake

Posted on Jul 01, 2022

On occasion our tech line gets calls from people installing rear disc brakes with the internal parking brake who find, on initial installation, that the brake shoes drag. The Wilwood internal drum parking brakes work on the inside surface of the rotor hat of certain rear brake kits. Because one parking brake mechanism fits many different brake kits, they do not come fully adjusted right out of the box.

However, adjusting the parking brake shoes is easy enough if you follow this simple procedure:

NOTE: Do not actuate the lever with the drum off when doing these checks/adjustments.

Inspect the shoe engagement at the anchor block. The shoes should be engaged in the grooves and roughly centered vertically in the block.
Next, take a measurement across the shoes horizontally and adjust them outward to 7"-7 1/8" diameter.
Then center the shoe assembly visually on the backing plate with the ends properly positioned in the anchor block.
Be sure the shoes are not hung up on anything, like the clinch nuts or the bolts if they are sticking through the clinch nuts.
Next, mount the drum, remove the rubber plug on the backing plate, and adjust the shoes outward by rotating the star wheel until the drum cannot be rotated by hand.
Back off just enough so it can be rotated and reinstall the plug. Some slight drag is fine.
Try the lever. It should actuate and release normally.

If you cannot get a good adjustment that lets the rotor spin easily, give our tech line a call and they can talk you through other things to check that may cause it to be outside the proper range of adjustment.

Wilwood tech line: (805) 388-1188

Exploded diagram internal drum brake rear

2 comments

Bryan at Wilwood: August 16, 2022

Because Wilwood uses the same star wheel adjuster for both sides, one will point one way and the other points the other. Often OEMs use a reverse threaded screw on one side, but we do not. This means that in order to make them both adjust the same way, one has to point the opposite direction when installed. The adjuster slot on the backing plate is an oval so you should be able to adjust it no matter which way it is installed. From the backside of the drum, pushing the star wheel down should expand it, pushing the shoes apart.

Bryan Wood
Tom : August 12, 2022

In the picture the start adjuster in near the front and on the exploded view it’s in the rear. Which one is correct
Thank you