Brake question

[pwrfool]

OK IDI gurus. I'm new to diesels so I have a question for you. The brake pedal feels very soft on the first push. It will build harder if I keep pumping. Do I blame a bad booster, master cylinder, or vacuum pump?

 

[79jasper]

Step one for any brake issues: check fluid level.
2. Manually Adjust rear brakes.

Sent from my SM-G892A using Tapatalk

 

[pwrfool]

It also looks wet between the master cylinder and booster, not dripping but def looks like a leak there

 

[IDIBRONCO]

Time for a master cylinder change. The seal between the master cylinder and the brake booster is seeping. You're probably getting air in the master cylinder when you release the brake pedal. The fluid should also be at least a little bit low in the rearmost reservoir in your master cylinder too.

 

[franklin2]

The brake pedal is getting hard because you are getting ahead of the vacuum pump. That doesn't explain the soft pedal, but pumping the pedal many times will overwhelm the vacuum pump and when your vacuum level starts dropping, the pedal gets hard. If you want verification of this, turn the engine off, and then press the pedal, it will be hard as a rock, unless you have some air in the lines.

 

[nelstomlinson]

I had way too much pedal travel - it was almost hitting the floor, and felt soft. A second stroke firmed it a bit. Adjusting the rear brakes fixed it.