With engine running pedal slowly goes to the floor

Hello,

This sounds to me like you have a brake fluid leaks somewhere. When you have a leak in you vehicle's sealed brake system, it will not be able to build pressure and the brake pedal will slowly fade to the floor. Brake fluid acts like hydraulic fluid by building pressure and squeezing calipers together with brake pads on them. The brake pads apply friction on a rotor which is attached to the wheel stopping your vehicle.
I have included a link for you to go to down below:

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Please go through this guide and get back to us with what you find out.

Thanks,
Alex
2CarPros

After clamping off nsf brake pipes the pedal works great. no leaks, pistons working.

NSF pipes? are those the flex lines or?

Hi, yes they are flexible pipes.

It sounds like you have air at one of the wheels. can I ask if the truck has ABS brakes? Also try to block off either the front or back to see if we can isolate which end of the truck is causing issues. Let me know what happens.

Hi Ken, when engine is not running brake are hard when running slowly goes to the floor clamp off nsf FLEXI pipes when running brake good.

Ken it’s not ABS.

Hello again,

Where do the NSF pipes run to?

Thanks,
Alex
2CarPros