She's taking a leak! Rear axle seal leak that is....

I know this thread has been dead for a while, but I've done some looking around and can't seem to find any answers. I was under my rig the other day changing out the transmission fluid when I noticed a bunch of fluid on the rear drivers side tire. I took the wheel off to inspect and I'm not positive it's the seal. The fluid seems to be coming from too high to be the seal and it doesn't smell like gear oil. But I don't see where it could be coming from that's the brakes either. Is there any way to check this without just going in to replace parts and all? Thanks! Ps, I'm new, take it easy on me!
 
Pull the rubber boots on the ends of the wheel cylinder back, if they're wet inside you've got a wheel cylinder leaking.
inspect_wheel_cylinder.jpg
 
Well, that was my other thought, especially considering it doesn't smell like gear oil, however, there is no smoking gun. I looked all around the wheel cylinder and didn't see where it would be coming from. That's why I was hoping to find a way to check if either is bad without just replacing parts
 
Ok cool. I recently did the wheel cylinder in my old f150, but it was obvious that it was bad, it was dripping. If It turns out to be the wheel cylinder, is that something that I should replace both sides at once or just on an as needed basis?
 
Really can't be too high. That gear oil just flings around in there. Usually, the gear oil looks like grease when you take your drum off. It does have a pretty distinctive smell too. Could clean everything up real good with brakecleen and pump the brakes numerous times then look at the cylinder. The sure fire way to see if the axle seal is leaking is to GENTLY remove the ABS sensor (1 bolt and a firm wiggle) and look inside for gear oil. Should be dry.

You can replace 1 wheel cylinder without the other. Good luck!
 
I'm missing something here. In a 3rd gen runner, a Tundra or Tacoma (possibly others) when you lose a rear axle inner seal the gear oil washes through the sealed bearing and renders it NFG. While the gear oil is bathing it they can go for years. Once a new seal is in the axle tube the bearing might not last even if you manage to extricate the plastic bearing seal and repack it. Standard procedure is to cut all the retainers and tone rings off, press everything apart and then back together which must be to a very tight dimension or it will not seal. The inner seal rides on the inner retaining ring. The second one I did already having all the tools took me and my buddy a whole day including the brakes. I can see an hour to do a side if you are replacing just the axle tube seal but that is only going to do any good if it's done preventatively before a leak.

Oh ya a price quote here from the stealership and an independent were both 1200 bucks for both sides and the brakes. after doing just one side myself I could see that quoted prices were not very far out of line. I made my own fixture for the press and machined a small standard for measuring when pressing the last collar and tone ring on. That took quite a bit of time but saved me hundreds. I've used them since on my buddies Tundra. Identical job by the way. Even the parts were the same except for one seal. His Tundra leaked because a dealership did the repair and pressed the collar too deep. The seal had no surface to contact. He fought with them for years over it and drove it leaking. When we pulled it apart the bearing was not so nice.

Catch those seals before they leak and replace them cheap and easy. Saves your brake shoes too.
 
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^^This That last retaining ring is critical to proper seal. I think many people are just pressing it all back together without getting that last ring in the right position. I used DR coffee's method and used grease on the retaining ring to check the position before putting it all back together. No leaks for the last 6 months (8000 miles) and this was the 2nd repair I made on this truck after owning it for about 1 month. Also, did the bearings. Use ONLY OEM parts. Definitely not a job you want to do twice.
 
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Well, turns out it is the axle seal. Didn't get as lucky as I was hoping too....

Make sure to check the dif breather and the bearings ( which may need attention since they bathed in gear oil for a while) for the cause of the seal failure. Don't know your mileage but if you're over 125K the bearings might need attention.
 
That was my plan to replace all of it while I'm in there just to be certain it's not going to go bad again because of the bearings. Plan to do the diff breather mod too to be safe. I picked the truck up a few months ago with 230k and I'm not real sure the previous maintenance done on it. I know it's been 120k since the timing belt was done.....so I'm trying to tackle a bunch of stuff to get it in tip top shape to be driven for the next infinity.
 
The breather plug was very very clogged, im surprised that it didn't cause the seals to go earlier than that. I dropped my axle off with the shop last night, they are supposed to be pressing everything back on today, so hopefully ill get it back on the road this evening. Im excited to have it back on the road!
 
The breather plug was very very clogged, im surprised that it didn't cause the seals to go earlier than that. I dropped my axle off with the shop last night, they are supposed to be pressing everything back on today, so hopefully ill get it back on the road this evening. Im excited to have it back on the road!

When you get the axles back, lightly smear some grease on the inboard (the spline side) retainer, which is the innermost ring (the last thing) that is pressed on the shaft. Insert your shaft completely and remove and look at the ring retainer. Hopefully it will be half clean and half still with grease. Only have about 3-4mm tolerance (probably less- mine was dead smack in the middle which made me very happy since I did the press work myself)). If it's wiped clean of grease or still has grease on it, your retainer is positioned wrong and will allow gear oil to leak by again. If the grease line is close to the chamfered side of the retainer or on it, it may not leak right away but will eventually leak prematurely. Good luck!
 
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When you get the axles back, lightly smear some grease on the inboard (the spline side) retainer, which is the innermost ring (the last thing) that is pressed on the shaft. Insert your shaft completely and remove and look at the ring retainer. Hopefully it will be half clean and half still with grease. Only have about 3-4mm tolerance (probably less- mine was dead smack in the middle which made me very happy since I did the press work myself)). If it's wiped clean of grease or still has grease on it, your retainer is positioned wrong and will allow gear oil to leak by again. If the grease line close to the chamfered side of the retainer or on it, it may not leak right away but will eventually leak prematurely. Good luck!

Slightly confused now, what will cause the grease to be cleaned off of the retainer? and look at it....through the ABS sensor port?
 
Slightly confused now, what will cause the grease to be cleaned off of the retainer? and look at it....through the ABS sensor port?

The axle seal cleans the grease (hopefully half the grease). You want the seal to ride (ideally) right in the center of that retainer. The axle seal rides on that inner retainer which is only about 10mm wide and about 2 or 3 of that 10mm is chamfered (beveled).

To answer the second part of your question, all you do is insert the entire axle into place until its flush in place, ready to put the 4 bolts in that hold it in. Then just take the whole axle out again (carefully) and look at the retainer. Takes about a minute or two and will save a lot of grief (and money)

Oh one other thing to make sure is that IF the shop cut the retainers off they didn't groove the shaft, which allows the gear oil to sneak underneath the retaining ring. Really nothing needs to be cut off if you know what your doing. Should be able to press all the components (2 retaining rings and ABS exciter gear) off. Still confused? I was confused reading all the write-ups until I did the job myself then it all made perfect sense.
 
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The axle seal cleans the grease (hopefully half the grease). You want the seal to ride (ideally) right in the center of that retainer.

To answer the second part of your question, all you do is insert the entire axle into place until its flush in place, ready to put the 4 bolts in that hold it in. Then just take the whole axle out again and look at the retainer. Takes about a minute or two and will save a lot of grief (and money)

Ah, im tracking now. Just some regular high temp bearing grease, right?
 
Ah, im tracking now. Just some regular high temp bearing grease, right?

Yep, just as long as you can see it. Don't cake it on there so when you pull the axle out it will leave a very clean border on the retainer right where that seal is riding. Please reread my previous post. I edited it to include another piece of advice.
 
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Well, looks like the shop pressed them on wrong. Took it back, they're overnighting parts, hopefully have it back tomorrow...fingers crossed.
 

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