I have a quick question, could be something, could be nothing. When I depress my brakes past halfway, I get a bit of a gurgling sound from my pedal. I know that sounds crazy, but just what it does. The brakes are in good condition, fluid is good and clean, and the truck stops amazingly well for that heavy of a truck. Is this something to do with the rubber lines, and could be remedied by steel braided lines? Thanks for any responses.

 

No one has experienced this?

 

you probably have water or brake fluid in your booster. When you depress the pedal the diaphragm moves forward and "squeezes" the water up to the point that it gurgles from the air entering around the booster pedal rod.

Are you a fairly handy person? If so you can check this yourself.

The first thing to do is confirm that there is liquid in the booster. Follow this process:
- turn off truck, put in park
- pump brake pedal 5-8 times to deplete vacuum in booster (pedal will get very hard)
- remove 2 nuts holding master cylinder to booster
- pull MC away from booster (watch for O-ring on flange... make sure it stays on flange)
- get a piece of string, or rolled up paper, or something and stick it in the booster opening to "fish" down and see if it gets wet.

if it is wet, you need to determine what it is and how it got there. If its brake fluid you need to put a new MC on... the rear seal went bad and its leaking into the booster.

If its a different fluid, let me know and maybe I can offer some suggestions.

good luck!

(reassembly of MC to booster is just the reverse... make sure O-ring is on MC, tighten both nuts to about 25 N-m torque)