2003 Ford Explorer XLS AUTO TRAN 2WD 156K miles. Used from private party.

Question

Hi scotty,

This is Hany with a 2003 Ford Explorer XLS AUTO TRAN 2WD 156K miles.

I bought it used from a private part. I took the car and was driving fine for 1.5hours.

Then after a month the break started to get week until one day it was not working at all. When i was parking on lever P only the emergency break can stop it. The break pedal shows no resistance at all and it make an air sound in & out as i press it. ABS light is one. However; when the engine is off i get a strong break pedal just like a brand new car! Once I turn the engine on; the break pedal loses pressure and became useless!

Here is what I did:

- searched for leaks. I see no leaks.

- Bled the break. No imporvement.

Here is what i did not do and why:

- I did not change the Master cyclinder because if it has internal leak, then it should have been the same regardless of the engine on or off.

-Since that issue is related to the engine running or not running; i felt it must be one of 3 things, ABS, vaccume valve or break boosters.

-->Do you think i am right?

-If it is the ABS and it is expensive to replace for me now. Can i disconnect the ABS and just drive the car with manual break?

- How can I fix/change the vaccume & valve going from the engine to the break booster?

FYI i am originally from Egypt and always drive manual transmission & manual breaks. When i came to America and saw Auto trans & ABS hydraulic breaks on small cars! I felt I am in another planet!

Thank you Scotty! I love you and your spirit; even if you did not see or answer my question.. But i will name my son Scotty if you answered!

Stay safe my favorite person & mechanic.

LIVE FREEE OR DIEEE!

Hany Haniness

scottykilmer · Answer

Hi Jerry you need at least a break booster they will sink like that when the booster is bad