07 rear drum brake leak

Ok so I was changing the oil today on my 4wd 07 tacoma and noticed some fluid seep on the back differential. Photo attached. I'm assuming the seal is going bad.

While taking a look at that I noticed my right rear brake drum and inner wheel was covered in dirt and an oily substance. The line going into the drum felt mushy at the attachment point so I thought it might be leaking from there but after pumping the brakes a few times I noticed a bead of what looks like brake fluid formed at the bottom of th drum. Pics attached.


I guess my question is does this mean the brake fluid line and the drum both need replaced?

 

^That "line" you photographed is the parking brake cable. Actual brake line is a rigid line that enters the backing plate near the 12 o'clock position.

Yeah based on your description, the wheel cylinder in the drum is probably leaking. Wheel cylinders are cheap on Rock Auto.

 

Ok wasn't sure, but the drop of brake fluid was at the bottom of the drum in the groove.

 

Looks like a bad axle seal, and possibly your 3rd member isn't properly sealed either.

Is your diff breather clogged? Happened to me. Diff Breather clogged with ice and boom- axle seal caused diff oil to clog up with drum. Very cheap part to replace (seal and breather).

Also, you'll need to take off your drum and degrease the thing like crazy with brake cleaner. At this point, you'll most likely need to replace the boots (do BOTH sides).

 

Based on Vixty's description it's probably leaky wheel cylinders. Anyway, brake fluid is thinner than gear oil, so it shouldn't be too hard to distinguish between the two.

 

Bad wheel cylinder,an easy fix too replace.Mine was bad on the right side rear of my ,took about an hour too replace,might as well do you brake shoes if need be while you are at it.

 

They truck only has 90k miles so the shoes are probably fine.
The fluid was thin that came off the bottom of the drum.

Can you make sense of the fluid leaking from the pumpkin?

 

BEFORE you do anything clean up both areas with gas or any grease cleaner,and then look at them again a few days later,you will be able too more pinpoint where the fluid is coming from in both areas.

 

I pulled the drum off and it looks like the photos below. It's very greasy inside, I'm thinking it's the axel greas or dif fluid. Smells like grease to me.

 

check the master cylinder fluid level

 

check the rear diff fluid level, 24mm socket

 

I topped it off about 8 months ago and now it's down halfway to minimum

 

Pull back those rubber boots on the wheel cylinder and look there for leaking brake fluid, if it's dry under the rubber boots then it's your axle seals. BTW those shoes are shot!

 

Your wheel cylinder is shot,and so are your brake shoes,nothing left of them,probably due too the wheel cylinder failing!

 

It should still be full ! your wheel cylinder is leaking for sure.

 

I pulled the rubber back on both side perfectly clean and dry

 

Then where is all your brake fluid going !

 

Fluid normal does not travel UP ,so I still think its the wheel cylinder since its mounted up top and the fluid leak is up top and everywhere else,and your wheel bearing seal is not up top so dont know how the fluid from that seal could travel upwards.

 

Looks just like my leak did,and it was the wheel cylinder which froze causing just that side brake shoes too be worn too nothing,just like yours is.

 

Lots of different input here.

To me it's an axle leak, especially if it stinks, on Taco's when they leak it sprays everywhere and makes a huge mess, even on the inside of the rim.

Brake cylinder leaks usually just look "wet" and can be easily diagnosed by rinsing with water, if it foams, its brake fluid, if it floats, its oil.

Problem with axle leaks on Toyota is that they leak through the axle bearing, and oil is then trapped in the bearing and will continue to ruin the next set of brakes until replaced.

You need a new axle bearing set to go along with the new brake shoes, drums, and axle seal.

Brake shoes and drums are porous, discard them.

I'm not a parts person, but this is what I usually quote when I see a leak like this.