Routing high-pressure fluid lines in tight spaces requires compact connections. A banjo bolt allows fluid to enter from any angle. The bolt is hollow with holes drilled through the sides. It slides through a circular banjo fitting, and fluid flows from the line, through the bolt sides, and down the center channel into the component. Two crush washers are required: one between the bolt head and the fitting, and one between the fitting and the component. Always torque them to spec. Over-tightening will snap the hollow bolt.
Mechanic Glossary
Banjo Bolt
A hollow, perforated bolt designed to allow fluid to pass through its center and sides into a banjo fitting, commonly used in brake calipers and turbocharger oil lines.
Frequently Asked Questions
Banjo bolts are hollow and much weaker than standard bolts. They require very low torque. Always use a torque wrench.
Yes. You must place one washer on each side of the circular fitting to prevent fluid from leaking out of the joint.
It is best to replace them. Copper washers harden after being crushed once and will leak if reused.
Most passenger vehicles use 10mm or 3/8-inch banjo bolts with a fine thread pitch.