Bad Brake Booster?

[Daniel McCurdy]

Also with the old booster with the truck on i would have to wait 5-10 seconds for the assist to come back after one pedal push now with the new booster i can press it a bunch and theres little to no lagg. So 100% the old booster was bad. Its possible the vacuum pump is a little week but at the booster vacuum line it would pull 20in almost imiedietly and climb to 21 in 1-3 seconds. So the brakes are a lot more consistant now and they do stop quick it just takes a decent bit of force to do it. Before when the assist was slowly coming back i could slam the brakes and i wouldnt slow down very much at all.

 

[Daniel McCurdy]

The only thing i find strange is with the old booster the first bit of brake pedal travel was a lot easier and braked harder, but then i would run out of assist and it wouldnt slow down much at all even with heavy pressure.

 

[david85]

Sounds like the booster was bad but so are some other parts.
What does your brake fluid look like?
Can you tell if the rear brakes are working?
How far does the pedal move before you start to feel it get firm? 1 inch from the top? Or 1 inch from the bottom? (this last one could mean low fluid or badly adjusted rear brakes)

 

[Daniel McCurdy]

The master is brand new so is all the brake fluid, there are no leaks anywhere. Rear brakes are definetly working as if i smash the pedal on a slick road itll lock the rear tires up. Pedal is instantly firm not soft at all anywhere in the travel and stays firm.

 

[Daniel McCurdy]

Keep in mind it doesnt have drum brakes anymore the rear axle is from a 2008 f250 with the big disk brakes.