I pulled the brake drums to inspect the rear brakes since I was having trouble bleeding the lines.

The left rear wheel cylinder looks like it is leaking brake fluid so I plan to replace that.

I also inspected the backing plate where it meets the square flange at the end of the axle housing. At the bottom side of the flange, a darker area looks like it might be a leak.

My question is, is there any chance that the leak at the flange might just be brake fluid from the leaky wheel cylinder--or does that leak indicate a failed oil seal?

I attached a couple of photos--one showing the wheel cylinder leak and one showing the backing plate/axle flange leak.

I was hoping someone who has dealt with an oil seal leak might be able to use the photos to confirm whether that is what I have here.

Thx

 

Looks like just the brake cylinder to me. Why not replace it and see if that solves it?

 

That's what I decided to do--just change the wheel cylinders.

I checked the rear bearings for play--they seem OK. And I don't recall any suspect noises coming from the rear end. So I'll clean things up and get the brakes working. Save myself some work for now. But now that the bearings/seals have my attention, I'll be keeping an eye on them. Cross that bridge if/when I get to it.

 

What does it taste like? (just kidding)

New wheel cylinders can be found at www.rockauto.com But always compare the pricing locally before ordering. They're usually great on pricing, but once in a while they'll surprise you. Good luck, and don't forget to bleed the system when you're done...

 

lol...but I did actually scrape off some of the gunk with a putty knife and tried to give that a smell test to determine which it might be...no luck...I couldn't smell a thing.

As a matter of fact, I did order my wheel cylinders from rockauto. I got a couple of their wholesaler closeouts which were about half-price. Just hope that doesn't mean that they have been sitting on a shelf for too many years.

I was lead to inspection of (and now replacement of) the wheel cylinders by a previous failed attempt to bleed the brake system. No matter what I tried, I couldn't get the mushy feel out of the brake pedal. Hoping for better success this next time around with the brake bleed.

 

A little followup...

After replacing both rear wheel cylinders, after several days I discovered that the right rear w.c. had a leak at the rear seal. I suspect it was a shelf life issue--the box the w.c. came in just looked like it had been around awhile. So I bought a new (full warranty) right rear w.c. and installed that. So far no issues but in a couple of weeks I'll pull both drums and inspect the w.c.s just to be sure.

[BTW, drum brakes are a PITA. While I was in there, I had both drums turned (now at the limit--next time will require new drums) and installed new shoes.]

 

Thank you for the followup. Glad you're making some progress...