2004 Suburban Z71 front drivers side axle/cv leak

[Twinsoffroad]

I have a 2004 Suburban Z71, and noticed a leak of some sort at my drivers side CV where it bolts to the axle. It’s on both sides of this flange, and doesn’t seem fresh- it’s dried out, and caked on there good. I also checked my front axle fluid and it’s so full it came running out the full bolt when I went to remove it so that rules out the notorious front axle seals (unless it was previously bad and replaced?) No clicking when going lock to lock either.

Would this definitely be the CV leaking? Does it need replaced? The boot is in great condition and I don’t see where the source would be. Any tips are appreciated! Still learning as much as I can about this rig.

 

[rockola1971]

Could be old remnants of a boot getting torn on a previous cv axle but I would more inclined to believe you have either an oil leak or power steering fluid leak. The dirt is just sticking to it and looks like its been there awhile unless you go offroading alot or constantly driving down dirt roads. Been using any oil or power steering fluid? Dont know how long youve owned the Suburban so it could be an old leak that has been repaired and just wasnt cleaned up.

 

[MassHoe04]

I agree with @rockola1971 on this. Leak is likely coming from above.
That location is generally below the Hydroboost unit.
Send some pics up top around the Hydroboost and the power steering pump so we can see what things look like.

Could also be leaky valve cover gasket on that side. Grab pics of the area of the head on that side too.

 

[Fless]

Most likely the differential stub axle seal on that side, very common. A little leaks out and the CV axle slings it all over. Mine is in the same situation, in need of a new axle seal.

 

[Twinsoffroad]

Could be old remnants of a boot getting torn on a previous cv axle but I would more inclined to believe you have either an oil leak or power steering fluid leak. The dirt is just sticking to it and looks like its been there awhile unless you go offroading alot or constantly driving down dirt roads. Been using any oil or power steering fluid? Dont know how long youve owned the Suburban so it could be an old leak that has been repaired and just wasnt cleaned up.

I checked around the area. Don’t see any obvious signs of leaks. The hydroboost area is spotless, I have some gunk residue below the power steering fluid cap but it looks like that’s just from filling it and spilling an ounce. The ps fluid level is a little low- it was still on the dipstick but right at the “add” line. Here are some pics too. No signs of any residue on the frame or areas under the hydroboost.

I’ve owned this for just a few weeks and unaware of any work done in this area. Previous owner only mentioned replacing the starter as far as engine maintenance.

To add also- the brake fluid level is good but it is very dark. I also need to press on the brakes harder than other vehicles I’ve had, not sure if that is a symptom or it’s just because this thing is a land yacht.

 

[rockola1971]

I checked around the area. Don’t see any obvious signs of leaks. The hydroboost area is spotless, I have some gunk residue below the power steering fluid cap but it looks like that’s just from filling it and spilling an ounce. The ps fluid level is a little low- it was still on the dipstick but right at the “add” line. Here are some pics too. No signs of any residue on the frame or areas under the hydroboost.

I’ve owned this for just a few weeks and unaware of any work done in this area. Previous owner only mentioned replacing the starter as far as engine maintenance.

To add also- the brake fluid level is good but it is very dark. I also need to press on the brakes harder than other vehicles I’ve had, not sure if that is a symptom or it’s just because this thing is a land yacht.

The hydroboost on these are notorious for leaking. The will leak where the master cylinder meets the hydroboost unit. The leak comes from seals on the hydroboost and it will leak power steering fluid slowly over time until eventually just pouring it out.

 

[Fless]

The hydroboost on these are notorious for leaking. The will leak where the master cylinder meets the hydroboost unit. The leak comes from seals on the hydroboost and it will leak power steering fluid slowly over time until eventually just pouring it out.

Good to know, but it doesn't appear that it's happening here. The stub axle seal leaking is a common issue on the driver's side front diff. All the pics point to it being that.

 

[Twinsoffroad]

Good to know, but it doesn't appear that it's happening here. The stub axle seal leaking is a common issue on the driver's side front diff. All the pics point to it being that.

Yes from reading before I posted this thread all signs pointed to that seal, however since my front diff fluid is completely full I ruled that out. Maybe it leaked and was fixed by the previous owner and a non-issue? I recently went down a very dusty road and no dust stuck on this grease to show how old it is.

I’ll monitor front axle/power steering fluids and see if anything changes. Also am planning on changing my front axle fluid sometime in the next few weeks.

 

[Fless]

A little fluid can look like a lot when it's allowed to spread. Ever seen a quart of oil on the floor? Would cover a 2-car garage floor. So even a few ounces will spread all over.

EDIT: you could clean it off and monitor it to see if it's still leaking, and from where.

 

[Twinsoffroad]

A little fluid can look like a lot when it's allowed to spread. Ever seen a quart of oil on the floor? Would cover a 2-car garage floor. So even a few ounces will spread all over.

EDIT: you could clean it off and monitor it to see if it's still leaking, and from where.

Good point, yea I’ll get some simple green or dish soap on there and clean and report back.

 

[Twinsoffroad]

An update for everyone- it is my stub axle seal. I replaced the diff fluid and that made it very obvious what the problem is. I now have my CV removed and trying to remove my driver front stub axle and I cannot for the life of me get it removed. It’s been about 3 hours of using pry bars/ hammers/rotating the axle and tapping/etc.

Any tips for getting the dang c clip on this to pop out? I’m worried I’m ruining the stub axle or the bearings inside at this point.

 

[rockola1971]

An update for everyone- it is my stub axle seal. I replaced the diff fluid and that made it very obvious what the problem is. I now have my CV removed and trying to remove my driver front stub axle and I cannot for the life of me get it removed. It’s been about 3 hours of using pry bars/ hammers/rotating the axle and tapping/etc.

Any tips for getting the dang c clip on this to pop out? I’m worried I’m ruining the stub axle or the bearings inside at this point.

 

[OR VietVet]

On another thread there was a member that could not get the stub axle back in with the cir clip on the shaft as it was installed and then it was determined that he needed to put the cir clip inside first and push it in till it popped into the groove inside the carrier and then install the stub shaft. I had thought the install process was the opposite and the clip needed to be on the shaft as it was pushed in to the carrier. I am unsure as to what is the proper way to reinstall the shaft. Now I think that the clip "could" be on the shaft and just rotate as pushing the stub shaft in, until the cir clip centers and allows the shaft to seat all the way in. Hell, I don't know. I wish the video covered that.

 

[Twinsoffroad]

My bad I didn’t update earlier, I got it out!! I separated the tie Rod from the knuckle so I could turn the knuckle left as much as possible, and loosely connected the slide hammer. Not 30 seconds later with two dozen good wacks and it popped right out. Got the new seal in and so far so good. Thanks OR vietvet for the c clip suggestion as I did not know what was right, lucky for me the c clip stayed in the front diff so no extra work was necessary.

Thanks for the help everyone! Love this forum