I was under the truck yesterday finishing some ladder-bar mess and some general clean-up (remove broken sway-bar mess, remove remnants of rusted away bump-stops, perhaps even replace that weeping wheel seal). What's that? The danged pinion shaft seal's gone to leaking.

Anyhoot, I want my ladder-bar install as smart as it can be. That includes taking the time to disassemble the parking brakes swivel adjuster thing so as to allow me to route the individual cables through the ladder-bars where needed. Same includes removing all the mounts for the right rear cable on it's way to the drum assembly.

On the way, there's a simple sheet-metal clamp that's sandwiched between the axle housing and the rear hydraulic brake Tee-block. The two are attached to the axle housing by means of the axle housing's vent hose fitting. The vent hose fitting literally passes through the Hyd brake Tee and the E-brakes cable mount.

Yours may look like this ~





OK fine. So I go to pull that assembly apart to continue releasing the E-brake cable and happened to notice this ~





The vent hose fitting's plugged with rusty-gum . . . . . . stuff. No wonder things are weeping lube oil!



Well folks, if you haven't checked it in a while, you might do well to chock the wheels, climb under the rear-end drivers side, and unclip the vent hoses vent end from the bed frames cross-member.
Now take a 9/16" open end wrench and loosen the vent hose fitting two or three turns.

STOP!

Wedge a flat blade screwdriver in there so as to raise the brake Tee just enough to blow, brush, what ever all the dirt and rust from between the axle tube and the hydro brake Tee.
Having cleaned all that mess to your satisfaction, go ahead and finish unscrewing the vent hose fitting.

Now take a small drill bit assortment and starting with around a 1/8th inch bit in your hand, screw it into the goo a little and pull the bit out. Wipe all the goo from the bit's flutes. Continue like this, advancing a little at a time till you get about two inches into the fitting. From there, it opens to the rubber hose. Now select a slightly larger bit and repeat the process. Keep getting bigger till you're up against the inner sidewall of the fitting. (Mine seems to have a slight narrowing at the hose end of the fitting). Just clean all the goo out.
I smacked the fitting end of the assemble on the bench so as to knock out any goo I might have pushed up into the hose. Then blew through it with compressed air for good measure. I didn't actually disassemble the hose, fitting, and vent-cap for any of this. You can if you think it's necessary.

Put it all back together in the reverse of taking it apart. Just be mindful of any trash that might get in the axle housing's hole.

In the same fashion, check the front axle as well if applicable. The front vent hose screws into the front hogs-head.


This should greatly reduce any weeping you might have with the axle and pinion seals as any pressure differences will be correctly vented through the vent hose instead of through your seals.

Hope this helps.

 

Nice job. Guess I know where I will be tomorrow afternoon.

 

That one went right in the sticky. Great post.

 

I'm glad it's worth your while.

When I first saw the new leaks, I immediately thought of a number of references to supposed new leaks after upgrading to synthetic lubes.

Having seen how my vent was plugged, I wonder how many folks who've seen leaks had recently put in synthetics and assumed it was the lube making the leaks. Is it actually their vent plugged? Are there big enough differences in the synthetic and Dino lubes (expansion/contraction) to account for the sudden leakage? Is it simply coincidence?

What would Dale Gribble think it was?

 

Black U.N. helicopters, most likely.

 

Now, let's not be poking fun at my neighbor.

 

Same thing happened to my Girlfriends 4Runner, I thought the axle seal was leaking, the vent cap was rusted shut on the diff. Freed it up, cleaned the inside of the wheel off and no problems since.

 

I had the exact same thing happen to me while doing some hotshotting services for my dad's business. I noticed my rear pinion seal (relatively new) was weeping and that lube was coming out of the left side of the axle. Brought it home and I took the fill plug off of the diff cover and I got a "pisssshhh" sound. Right after that I pulled my breather and blew out any crud that was in there. I had to do this again about a month or 2 after that and this reminds me that I should check it again. Thanks, not only am I fixing my tailgate handle but I now have to check my axle breather.

Edit:
So while repairing my tailgate handle, I checked the breather. Now before I only checked the rubber hose and it was plugged so I took it off and blew it out and thought it was all good. Today I did pull the actual steel thingamob and it was plugged up real good. Took the drill bits on a slow drill (ie less than 100rpm) and voila! Problem solved. With the age and miles on these trucks this is something that should be checked. I'm glad I did before I start replacing seals needlessly.

 

EDIT ~

If you have a transfer case, you might as well have a peek at its vent pipe. It's very similar to the axle arrangement and is located just above where the rear drive-shaft plugs in.

 

I know, this is an old post, BUT! Thank You BC847. Your warning on the Dana vent clogging was right on time. Today I checked the vents on my axles and found the rear so plugged that it took a drill to open up the fitting. Thanks for the heads up. You saved me a ton of repair bills.

 

I actually went to the local Dealer and checked the availability on the vent/hold down bolts. somethings that you expect to be really expensive are cheap and a part that should cheap is expensive.. So anyway they were like 2.25 ea. I ordered 5 of them!! Just throwing it out there that they are available and relativly inexpensive..

 

Mopar part number is 4137 696AB and list price is $2.50 (8/20/2012).