Fluid in rear brakes ?

Had my truck in for an oil change and of course they do they obligatorily brake inspection. During the inspection they found the rear brakes are soaked with fluid and that I should replace my rear brakes. I of course asked what was leaking and they couldn't see any leak. Anyone have any thoughts? I have about 100k on the truck and its been for the most part rock solid. Did just have a leaf spring break but Toyota is covering under their TSB.

My break fluid reservoir has not moved

 

Fluid inside the drums or on them?

 

Rear diff gear oil ... bad axle seal?

 

Inside. Should have been more clear

 

They told me that the seals weren't leaking. If it is the axle seals. Is it a big job? Any idea the cost?

 

I haven't had to do mine, so I can't help there; but the only fluid I can think of back there would be from a bad axle seal. Hopefully someone will chime in with difficulty level and approximate cost.

If they say the seal isn't bad, what is their explanation of the fluid? You should pull the fill plug on your rear diff to check the fluid level. If gear oil doesn't seep out some when you pull the FILL plug or you can't feel the fluid with you finger in the fill hole ... that fluid went somewhere. I'm analyzing why they don't see evidence of a leak from the seal area ... if the oil has leaked far enough down that it's no longer filling the axle tubes laterally from the rear diff housing, that might explain it. Good luck.

 

wheel cylinders or axle seals?

 

You know ... I'd have to break out my Chilton's when I get home ... I'm not sure axle seal is the right term/name for 2nd Gen. I do know the fluid runs out the axle tubes from the diff housing, so there's some kind of seal at each hub ... or so I'm assuming.

 

either the brakes are leaking or the axle is leaking

fluid doesn't just get in there unless it is water

axle leak is the #1 culprit for oily rear drums