Funny rear brake question

Hi everyone,
I've been getting ready to change brake fluid/re-bleed and possibly change out anything that needs replacing on my 2002 Tacoma TRD. Found it very odd that my driver side rear drum appears very, very different than my passenger side.

The drivers side drum appears almost new, shoes barely worn, almost no dust about anywhere, and a sort of a trace of weird gummy residue present on outside rim of drum.

The passenger side drum appears like what I would expect: Brake dust everywhere, worn shoes, etc.

I've own this Tacoma for a couple years, put about 20k miles on it, and have never checked the brakes before. The brakes have always seemed very weak, but never had it pull to either side or lock up at all (it's actually somewhat impossible to lock these brakes except at low speed on asphalt in the wet).

I don't have much experience working on drums.

 

Is it possible that the drivers side isnt adjusted out correct? Is it snug to pull the drum off and put on like the passenger side?

 

It was slightly looser on the drivers side (no wear/dust) than the passenger side. For the drivers side, I had to pull quite a bit, used some moderate force to get it off, wiggling it back/forth. Was a touch more difficult on passenger, had to use hammer to tap around hub/etc. Could it just be an adjustment issue?

 

Leaky seal? A little bit if gear lube will prevent the shoes from ever wearing.

 

That's what I'm thinking. I've only worked on brake drums a few times myself but i know the rod right below the wheel cylinder with the gear on it rotates and locks against the 90 degree looking bracket. I was taught when replacing drum brakes to click the adjuster out until you feel drag on the drum. But from what force your saying it took to remove them, it doesn't sound much different from the other side.

 

When I wipe the shoe with a clean finger, there's a slight oily residue, leaves a light smudge on the finger. On the normal side wiping a finger just leaves brake dust on finger, and the shoe is smooth. That said, I can't see anything at all coming out from the axle seal area. Appears normal except no dust.

 

Yeah, not a big difference.

 

Wonder if theyre could be something wrong with your wheel cylinder not allowing the brake to work correctly ?? I've never seen a bad one. Only leaky ones. pull the boot back a little on the wheel cylinder and see if any fluid is right behind the boot.

 

Does anyone think it'd be a bad idea to pump the brakes with both drums off and see how the wheel cylinder works on both sides at the same time?

 

Yea it'll pop a cylinder out and you'll loose your fluid

 

Only 1 of 2 things would cause an oily residue in the brake drum, and both will cause the brake to fail. It’s either a leaky wheel cylinder or an axle seal leaking. Need to diagnose which it is and fix it before replacing both shoes and drums.

 

Alright, thanks guys. I suppose still possible even if I do it lightly? Yeah, probably have to find another way to check.

I did pull the boots back on the cylinder and there was a tiny bit of fluid on one side. Didn't really look leaky to me, like maybe a 1/4 of a drop of fluid there. Wasn't seeping out the bottom of the boot or anything.

 

Okay, very good to know. I do have to accept there's definitely an oily residue in there that isn't present on the other side.

 

Should not be any visible fluid at all. You may have discovered your culprit. Also, if it’s diff oil, it will smell like ass. Brake fluid doesn’t have the stench gear lube does.

 

I vote bad wheel cylinder. If it was the axle seal youd have fluid in your drums. Looks like the cylinder isnt working at all, so you've essentially never applied the brakes on that side. Id keep the drum on on the good side, and lightly tap the brakes while watching. If you go slow and easy youll be able to see it expand without any risk. If it doesn't move, it's bad. Could be a massive air bubble in the line or cylinder, a pinched brake line, or a faulty cylinder

 

Good point about the ass, it's been awhile, but I've definitely smelled diff fluid before, and this doesn't have any particular oder at all as near as I can tell.

 

This sounds reasonable. I think I will do this and see what happens. It might take me a bit as I'm cooking right now, but I'll post the results.

 

Yep shouldn't be any fluid behind the boot at all. If there is any fluid there, that's your problem.

 

Just be gentle and it'll be fine. I've be to hell and back with my rear brakes the last couple months and have taken apart, reassembled, and bled then probably 10 times in 2 months lol. I've pumped them without a drum numerous times and as long as you watch and go slow you'll be good. Should be movement in those boots with very little effort. If the boots move and cylinder is working, then your star wheel adjuster is probably stuck and prevented the brakes from self adjusting. They tighten on their own

 

Alright so did the test. Put drum back on the good side, then had wife slowly depress the brake pedal. I'm attaching a video as best I can, but there is some movement there for sure. Perhaps not as much as I'd expect, but there's a little movement.
Here's a link to the video of the test:
https://youtu.be/LTVE_uE97nw