Hubs - Diesel Forum

firedog533 · 10-11-2009, 02:35 AM

2003 f-20 4x4 front hubs will stay locked if turned in but will not stay in when in auto left hub been replaced all balljoints replaced new seals and o-rings

**MikeL46** · 10-12-2009, 08:39 PM

Sounds like you have a vacuum leak. There are alot of hoses to check. But, if your defroster/heater/ac vents work normally, then it is just in the 4x4 system.

Mike

patrickrc51 · 10-12-2009, 10:16 PM

The 4x4 system is seperate on my 06. The valve and pump should be on the pas/front. just follow the vacume tube from the diff up. The best way to test the system is to get a vacume tester and test each hub seperatly. They should hold a vacume for like 15min with no loss... I dont remember the exact numbers.
Mine did the same thing when I had the front gears changed out. They told me that they replaced all seals and o-rings but I know they didn't because I tore the whole front end apart and replaced the ball joints and the seals were all beat to hell from knocking them out and reusing them. The whole seal and oring kit is like 200 bucks.
You prolly have a bad seal on the inside of the knuckle. It is a huge steel/plastic spring loaded seal. with a dust cap over it.
P