I'm still new to working on the 240 platform and I've encountered a weird problem while driving. When I accelerate, my brake pedal will make a pop noise and pushes towards me. The brakes then engage without me touching the pedal. I'm assuming it is a vacuum leak or related to the brake booster; however, I wanted to see if anyone else has had this problem before.

If you have any advice, that would be very much appreciated!

 

The booster and booster check valve should hold vacuum with the car turn off. Start car, depress brake pedal, turn car off, if pedal rises the vacuum is leaking. Check your check valve - it's the plastic 90 degree fitting where the vacuum hose connects to the booster -