Funny rear brake question

I would expect a cylinder to pop out. Lol I still say that's your problem.

 

Yeah, I agree. She said halfway down was how far down her pedal foot got. I just feel like it should have moved more than that. It just barely moved, was actually kind of hard to appreciate.

Tentative plan for tomorrow is replace the cylinder (and drums/shoes since I feel like they're all coated with that residue) and see how it goes. Was planning to change the pads on the front wheels, but given the amount of problem I seem to be encountering in the rear that will have to wait for the time being, try and sort one thing out at a time.

 

On that driver side, pull the ABS sensor and turn the axle. If you see gear oil being lapped up onto the ABS tone ring, your axle seal has failed. Several have guessed it's a leaking wheel cylinder. It's my guess your axle seal has finally failed.

You might benefit from these two videos:

https://www.youtube.com/embed/AVhSDnw2ugo

https://www.youtube.com/embed/IJkVEBYSecs

 

Actually, since you mention that, the rear brakes only adjust if you apply your parking brake.

 

Thanks for the videos, man that's intense when he starts using a 20 ton press. So, well, I hope that you're wrong about the axle seal, but I'll check it out, see what it looks like. If I figure anything out for certain I'll let everyone know.

 

I do use my parking brake frequently, so I guess if it's the adjustment, it's a seized star adjuster nut. But with the residue, I'm feeling this is less likely.

 

Yeah if that was 50% breaking power then your shoes should have pushed it pretty far. The fact that they didn't budge tells me your not getting any pressure on that side. Is your master low on fluid? Something is preventing that cylinder from functioning and in guessing it's likely just a bad cylinder. Or less likely but a massive air pocket in the line or even in the cylinder. That's my vote

 

Brake fluid reservoir is steady, never budged since owning the truck, still is right where it's been (as far as I can tell). I managed to get a autozone wheel cylinder last night before they closed, will try and change it later today. I'm thinking I'll change it, put new shoes on, and maybe just clean and reinstall the old drum? And I did buy new autozone drums ($54/each) that I'm thinking about using as it definitely seems like one has been being used for last 20+ thousand miles and the other one hasn't, so they're probably worn differently, right?

 

That side has had new parts put on it but it's so clean that I would say that side has never actuated (worked). Bad
wheel cyl.

 

Oh hey man, you're Timmy the Toolman? I wanna say thanks for you video on valve cover gasket replacement (https://www.youtube.com/watch?v=N5fAXAuGozI), awesome video! I was super nervous about that job until I found your video, with all the specs included and everything made me feel much more confident. I'm around a thousand miles out from that repair and no leaks at all. The only thing I did different was just Permatex black instead of FIPG, but seems to be okay. Next time I'll use FIPG for peace of mind, but at the time was trying to avoid another trip to dealer.

 

I bought new Brembo drums on Ebay for abt. $60 ea., brakes really smooth now. Chinese drums often are not machined true to center line & give a bad pedal pulsation.

 

Yeah if possible I'd like to wait and not use the autozone parts. Even on their own website they have some pretty bad reviews.

Here's the update so far: I wanted to check for gear oil getting in the wrong spots as described by Timmah! above, so here's the check I did:
https://youtu.be/OVoFVXEduAM
Not really sure the meaning of the results of this, but it looks pretty normal to me. Never checked in axle like this before though.

 

Dude, you just found out your problem and it's not normal. If the axle seal was holding, there would be no gear oil in the area of the ABS Tone Ring because the axle seal sits more inboard on the axle housing and makes a seal with the inner retainer on the axle shaft. The ABS tone ring was lapping up gear oil in the video you posted. That gear oil is now getting into your brakes and it's also working it's way into your axle bearing. The gear oil will slowly wash out the grease and ultimately cause the bearing to fail because the bearing needs grease for lubrication, not gear oil.

I suggest you pull both axles and replace the bearings, axle seals, brake dust seals and o-rings on the ends of the axle housing. The reason why I say do both sides is because the other side is probably close to failing too if it hasn't already. If you watch the video I posted, it shows you how to do it all yourself if you have the necessary tools. In the video description, I also describe how you can save money on the parts by reusing them if you pull the parts off rather than cut them off. If you don't have the tools, you can pull the axles yourself and have a machine shop or auto shop do the work for you. Just make sure you watch the video so you understand the repair really well so you can tell them exactly how you want the parts pressed on, mainly the position and orientation of the inner retainer. I tell you this because this has got to be the #1 repair shops screw up. Even dealership screw this repair up because they don't understand all the nuances of this repair, mainly the fact that the seal was redesigned by Toyota.

 

Ahh okay damn. I just checked the other side and it's the same as the drivers side. I guess I'll just reassemble it and wait till I can get everything together to fix it all.

 

So a final update: Given the above findings (both rear axle seals leaking, needing a more involved fix than I can do right now) I decided to put off definitive repair for today and reassemble without new components. But before putting wheels back on, I decided to flush and bleed the brake fluid, on the thinking that it costs almost nothing and who knows maybe there's some air in one line (because despite discovery of seal failure, it certainly seemed like some issue causing drivers rear to not be getting any wear at all). So I bled and it really seems like much more air came out of the affected brake. See the video of the excess amount of bubbles:

https://youtu.be/wkQcd8rXPy8

And here's one of the non-affected brakes being bled for comparison:

https://youtu.be/gSDr1bJweJA

Unfortunately I've driven it and the braking performance seems exactly the same... So onward I guess with the other obvious issues/repairs.

Of note, I did some googling/watching on cars with rear axle seal leaks, and it seems mine is not nearly as severe as those that have had videos uploading. Obviously I have a leak, but the amount getting past the bearing into the brake is low. After about a week I'll re-check everything make sure nothing is getting worse and see if maybe there's actually some wear pattern on the affect brake possibly from the bleed. Soon enough I'll approach the axle seals but haven't yet decided how much of that I want to tackle myself.

 

Dirty Pool has a lot of good info on replacing rear axle seals - it's good to read up on what he has to say in conjunction with @Timmah!'s videos

https://www.tacomaworld.com/threads...eplacement-videos.487287/page-3#post-17009998

https://www.tacomaworld.com/threads...eplacement-videos.487287/page-2#post-17009638

 

Check the differential breather as well. If that is plugged it puts the differential under pressure as it heat up. This pushes gear oil past the seals.

You may just get by with fixing that and not have bad seals at all.

 

Yeah thanks. I did check that as well. It was caked up with some dirt/mud, but broke it free and took it off. Air moves through it adequately I suppose. Blowing into the back of the valve allows small amount of air to slowly escape. Anyhow there's so much oil past the seals already think I bound to start fixing stuff there.

That's good to know. So far I've only watched Timmah's vids and read the posting but Guns 'n coffee. Thanks.

 

I think your drivers side drum is working perfectly....the rear drum brakes adjust the more or less your payload. They don’t get used hardly at all. The front brakes are 80% of your stopping power. The passenger side rear drum is also your parking brake. Check to see if you have no binds.....seems to me the passenger side is wearing out quickly.

 

I agree, it's weird. Passenger side is more than half way gone, dust everywhere. Close inspection of the driver side shoes looks like they're only partly scored by the drum (?!?) and no dust, just trace oily residue. Anyhow, did the bleed and complete fluid flush, seemed to get more air out of the line going to drivers drum.

And I will correct my earlier statement regarding brake performance after my flush/bleed, the brakes are working better now. Today did a daylight, highway speed re-test of the brakes. Was able to partially lock the fronts at 65 mph, which is a substantial improvement over before. Could never do that previously. It's been raining on/off since I did the flush/bleed so couldn't properly test until today. I'll take the drums off in a couple hundred miles and re-check the wear patterns. I'm still in planning stages for rear axle seal replacement, and I really appreciate all the great info other people including Timmah! have put out there on that.