Hub oil

You should see my Tahoe going through steering box oil. I carry a few bottles and that's all gone in maybe 40 miles. I will either have to replace the box or the entire system of lines to and from that box or all of them. But for now i can kick that can down the road with a few pints of steering oil among others in the tool box. It's a older vehicle and the biggest risk of losing fluid is that the exhaust manifold is there so if I come apart near that it's going to be a pretty good engine fire. Which wont be the first...

 

Seals can start leaking while a truck is parked overnight. A good pre-trip never hurts.

 

Here is a good pic... Of a REALLY badly leaking hub, on a truck steer axle. This truck was put OOS by DOT for this leak. If you see even a little oil streaking a rim or tire in this fashion you NEED to get to a mechanic shop... Like I said when they go they go fast!

 

Just like cattleman 84 said.
The oil when it starts to leak your lower brake shoe will look damp.then wet.

As it gets worse you will see the fluid streak like picture in last post.
When the hub gets low on oil the bearings heat up and start to burn the oil.

Another suttle clue is when you park for a few hours you might see oil stream down the tire sidewall.

 

Indeed... And once bearings burn off the oil really bad #### happens...

@Dumbitfown4me have you seen the news stories about sets of duals coming off trucks and trailers and causing accidents??? That is the ultimate worst case scenario for a leaking hub that is not taken care of promptly. If a steer axle hub assembly comes off like that at highway speeds there is a high likelihood of it causing the truck to jackknife, or even rollover.

 

go find you a very dry dirt lot. spin up the dust heavily. the dust will stick to any leaking fluid.

 

I can generally smell gear oil if one is starting to leak.
The picture of the outside of the wheel covered looks like a hub cap leak instead of a seal leak, simple easy fix.
Dot can and will shut you down if the brakes are wet or it leaks bad enough to drip,
I have not seen it mentioned, but one of the main reasons the steer axle seal starts leaking is not cleaning the vent out on the rubber stopper on the hubcap, lets it build up pressure. The same with seals on the rear, except for a different type of vent.

 

Here is a decent image. It's probably from a front wheel drive car, but the concept is the same. You have a pair of seals that keeps the hub oil in. but the seals need to be right against a piece of spinning metal, or being spun against a piece of metal as the wheel turns.

It doesn't take too much for them to start leaking. a bad alignment or out of balance tire isn't going to help. Maybe they weren't put on or replaced just right and they start to leak.

I've never smelled one that was leaking, but I'm a smoker. I don't smell or taste much...
You really need to get under and check the inside of the rim/wheel to check for leaks.

 

And to go a little farther Beyond The Hub oil itself, make sure every day you check your oil and your water. Look at the belts and hoses make sure nothing is ready to come apart or break. If you find that you have to add, keep an extra close eye on it because it may be a leak that's going to get worse.

You should also get into the habit of looking under the truck to see if you see any oil or antifreeze on the ground when you park it to go in and get a coffee or whatever else.

It's a good idea to get into the habit of looking onto the back side of your wheels to see if you see any oil there.

And as far as pre trips go, it's a good idea to really look closely at your lug nuts that everything looks secure and straight and that the rim is not cracked or having any other problems.