I read a post a while back about how to tell (maybe) if the braking issues were the servo, or masyer cylinder, or whatever. Now I cannot find it. So someone give an answer please, searching has several different variants of what could be wrong.

2004 Disco S, 134,000. Poor braking after it has been sitting for 6 weeks.

If it is running I can pump and get good pedal resistance, but poor stopping. Before I could pump it once and had good braking performance.

If it is not running I can pump it a few times, and soon as it starts the pedal gets soft and goes down a few inches. With pressure still on the pedal I turn it off and it pushes itself back up hard.

What would this point to first? I know I should replace the lines, bleed and use DOT4. But need to figure out the other issues first and do it all at once if I can.

What do you all think?

 

When the engine isn't running if you pump the brake pedal it comes up rock solid and then start the engine and it becomes softer and drops a couple of inches, that's normal, it's a function of the brake servo. If the pedal pumps up solid all the time with the engine running the servo isn't working. If the truck had been standing around unused the braking will be cr@p because the rotors are covered in surface rust and the calipers and pads are stone cold. After driving for 30 miles and using the brakes intermittently the braking should improve. To speed this up drive down the road and apply the brakes in short bursts whilst still under power, left foot braking. It will clean up the rotors and pads also generate some heat into the system.

 

Sounds like the combination of the servo and sitting. I will look into the servo and do what you suggested with the driving. Thank you.