I am in the process of replacing the front hub seals so my ESOF works again. I tested both front hubs with a mityvac and neither one of them holds any vacuum at all. All the lines are good, and the pump and solenoid seem to be working fine.

I have the driver's side apart and I have a couple of questions.

What's a good source for the vacuum seal? I've checked rockauto, riff raff, and diesel o-rings. Diesel o-rings has it, but the description says it's only for 2003+ Excursions so I didn't order it.

There is no yellow o-ring anywhere on the hub. I assume that someone forgot to put this o-ring back in and this is why I don't have ESOF? I guess what I really want to know is that there isn't some 2000-specific thing where there's no o-ring, right?

After I got the hub off, I spun it around on my workbench and it doesn't sound good at all. It makes a slight metallic grinding noise about 1/2 way around. I assume this isn't normal? AFAIK these are all original parts - but the missing o-ring means to me that someone already had it apart.

There was a lot of water intrusion and rusty colored grease but nothing was dry, the needle bearings were intact and the shaft isn't scored at all where the bearing rides. I'm hoping new seals and good cleaning and it should be good as new.

And then it's off to the next side.

 

If the hub is making a grinding sound it needs to be replaced the unit bearings in it are shot. Just cleaning and seals may fix your ESOF but it wont fix a bad bearing.

 

I got the other side apart today. This side had a yellow o-ring on it so whoever did the driver's side last didn't bother to put all the pieces back in.

The needle bearing on this side wasn't dry either but the axle shaft is pretty scored up where the the bearing rides. I think I'm going to have to replace that stub shaft.

How do the vacuum seals come off?

 

You have to pull the axles out...Take a big screwdriver and hit the seal from behind. It will ruin it but it should be replaced. Or with two big pry bars pry on the ujoint...Watch utube vids....99-04 should be the same..

 

Both axles are out of the truck but the seal is still attached to the stub.

 

Rip that sucker off there.... Hit it with a BFH

 

Update: Now I have both sides apart and found that I need two bearings on both sides. I also need a stub shaft the passenger side as this one is too scored up for my liking. The needle bearing wasn't dry but the shaft has a bunch of deep score marks. It looks like an installation problem by a previous mechanic to be honest. My fingernail catches on the marks so out it goes.

After reading up on here and other places I realized that I'm supposed to have a dust seal on both sides. There was no seal on the passenger axle. After looking at it carefully I saw where the seal is supposed to sit on the axle but there is just as much scale and rust on the seat as there is on the shafts. I bet it's been ten years since there's been a seal in that side of the axle. I cleaned up all the seats and the knuckles with a wire wheel so it's almost like new.

I really wish I'd done all this when I got it instead of putting 40k on it like this. I might now have done some of the off-reading that I did had I known.

 

Do yourself a favor and get Spicer life joints and do both sides while you have it apart. I think the number is 5-1350x.check the ball joints.