rear axle seal? leak and brake performance
 

Just replaced brake pads and rotors front and rear (got the $494 EBC kit deal from AB, thanks for the tips). Discovered heavy grease inside both rear rotors. The gunk had also spit up onto the pads and calipers.
The mechanic helping me said I need new axle seals, but after reading a few posts here it seems the only fix is new hubs? Or poss. my axle breather tube is blocked? Am I just losing axle grease or diff fluid or both? How do I check if my fluids are low? If the leak is slight can I keep driving it this way, adding lubricant when necessary?

Question about brake performance- I'm worried that the grease I found around the rear pads was getting to the rotor/pad contact surface to some degree, creating poor rear braking. Now my rear rotors had barley a lip while the fronts were very low, and same story with the pads- thick rears, worn-to-the-metal fronts. Dealer service records show rear pad and rotor replacements at 50k and fronts at 53k. I understand that fronts wear much faster than rears but the difference in mine seemed unusual.

Now that I'm probably facing another multi $100 repair cost- is there a market for good used OEM rear pads and rotors? I'll even throw in the mostly worn front rotors for free!

Thanks for any responses.

You are loosing gear oil that keeps your diff and axel lubed. You'll need a new hub, there is no repair kit.

E-mail me your tele number and I'll call you right back. In the mean time, don't drive it and get gear oil on the new pads.

You check the gear oil by a fill/check plug in the differential, it is the top plug on the back of the rear diff and on the front of the front diff.
With the truck level remove the plug, stick in your finger, does it get wet? If you cannot feel gear lube then you need to add.
Yes a clogged axle breather can cause a seal to leak, easy fix.
Yes you can replace the axles seals without replacing the hubs. You still need to remove the hubs to do it, but you dont need to replace the hubs to make it stop leaking.
Look for a clogged axle breather first.

Thanks! Just spoke w/ Mike on the phone. He thinks it uncommon for an '04 w/ 70k miles to have a leaking axle, but dang ****ay here I am. I could go the $195 per hub route used but guaranteed by roverland, or try the new seals at $6 each. Just a little worried that I won't be able to install the seals correctly as I'm a novice mechanic at best.
I will check the fluid level soon. I do need to do this job soon also, as I risk contaminating my new "green stuff" kevlar pads and I suppose the new EBC rotors are at risk too.
Where is the axle breather and how do I check it?

The axle breather is on top of the axle next to the diff, it is a hise that snakes up the frame of the truck.
Take it off and blow through it with your mouth, if no air goes though you need a new tube.
If it does you may need a new nipple that is on the axle, that just unscrews, you can buy the whole kit at AtlanticBritish for like $30.
If it is just the hose that is clogged you can but vacum line at AutoZone in that size and length, $1 per foot.

my '99 with 75K miles was leaking and getting on my rotors. I replaced the $2 O-ring gasket, not really sure that helped..but what did help was draining diff fluid, replacing with heavier gear oil and a shot of lucas hub oil.

sounds like a good quick fix. Anyone else have success with that?
About the breather tube- its the skinny tube coming out of the left side top of the rear axle, and it runs on and tucks in past where the eye can see? Mines on tight, did not come off with a hand pull. Before using a pair of pliers, I thought to make sure forcing it off was ok? since I'm worried about the nipple connection being a weak plastic thing that I might break in the process.

6 dollar seal? Holy crap. I had been told there is no servicing the DIIs. DIs yes, but DII no.

Thinking about that bill now makes me want to puke.

On DI's the axle breather nipple is brass.