I recently noticed a grinding noise coming from my front wheel, and my 4x4 didnt work. So, I purchased a new hub locking solenoid thinking that was the problem. After that was installed, the noise was still there, but I could lock into 4x4, so that was part of the problem. I hooked up a guage to each vaccum line on the front hubs. The drivers side has 15 lbs of vaccum, but the passanger side has only 5ish.

So I bought a new hub actuator and installed that, but now I still have the issue of my passanger vaccum line either being pluged or it has a hole somewhere.

I was trying to trace the line back up through the wheel well and back to the solenoid, but I cant seem to figure out where it runs or where the inline vavles are so i can replace them?

Anyone have this problem and fixed it before? Is there a good diagram that I could follow?

Thanks for any help

 

I have similar issue I here a grinding noise coming from front end every once in a while and then I click it in 4x4 high and noises stops right away then I noticed my 4x4 light on dash wasn't going on noise hasn't happed since summer so I kind of forgot about it no one knows what it is ?

 

https://www.f150online.com/forums/ar...then-some.html

 

Well...I replaced my hub actuator and the hub locking solenoid. Got it all together and took a ride, noise was gone. 2 days later the noise came back, but not constant, on and off. So I decided to check the vaccum from both lines. Drivers side had read 15, and the passanger side 1 maybe 2. So yesterday I removed all my vaccum lines and inspected and blew them all out, and they all seemed to be good. Hooked everything back up and hooked up my vaccum guage to both sides and I had 15 from both, so Im good to go right, nope wrong! Still grinding once in a while.

So what is happening is my vaccum to the passanger hub is losing vaccum, then gaining it back. Could it be a bad hub locking solenoid I got? What else would cause my vaccum to varry like that?