91 170k. I am having a down hill vibrating brake problem. So started checking the brakes. Starting with the rear. I found that the driver rear has some kinda Oil all over it. Not sure. If its Brake fluid (bad rear wheel cyl.) or diferencial fluid. Maybey my seal needs replaced. My question. How do I figure out which it is? and, could this be the cause of my extreme vibration on braking?

 

DOT brake fluid will feel sort of dry on your skin as compared to oil which is slick and greasy. Also gear oil has a very distinct odor and it's not pleasant whereas DOT brake fluid has virtually no odor or at least it's not unpleasant.

 

OK did some searching. Thanx for the help. Yes will research the substance more closely. Tomorrow. With the touch and feel meathod. As for the SMELL part I will have to gues on that. Thats the one of the 5 senses I was born without. I read I should also check my Defferential breather to make sure its not clogged, and pushing oil past the seals. Another way is to whipe it with a White rag or papper towel? to see what color it is? anyway thanks again.

 

It's your axle seal that's leaking. unless you have a press, it's best to take it somewhere.

 

if it does turn out to be your seals, youll probably need to do the rear bearing as well seeing as how you have everything apart. check around for members nearby, im pretty sure you will find a few that will offer to assist in this job.

lee

 

The gear oil will have a much thicker consistency to it, gooey, and it should be a golden coloer as opposed to the brake fluid which is much thinner - thinner than engine oil and is almost clear in its new state. Used brake fluid gets darker. You'll definitely be able to tell the difference rubbing it between your fingers. Gear oil will cause the brakes to grab too if it gets on the shoes. I think anthony1 is on the money here.

 

break fluid is water soliable(butchered that)

 

Yes, I think you all are in the right direction. I took the defferential breather off and blew into it. It was clogged. Cleaned it. and stuck it back on. Check the differential fluid for the first time sence I've owned it (3yrs). It looked great..Only there was way too much in there. Once I got the refill cap off, wich was a PITA. It poored out. I let a little out. Put it back on. Cleaned the brakes up with brake cleaner spray. And put it all back together. My hope is Oil was being pushed past the seals due to the overfill and the clogged Diff. breather. I will keep an eye on it and see how it goes.
Thanks alot for all your help. Any other suggestions are appreciated.

 

If it is diff oil, your seal is gone, and this may also be affecting the axle bearing. Gear oil works to remove the grease in the bearing. No grease, bearing burns up quickly.

It is my understanding that when the axle bearing goes, the axle will walk out of the housing. This may be a slow walk, or a quick exit. The bearing holds the axle in place, so to speak.

This is not a leak that should be neglected. You don't wan't your axle to leave the vehicle at any speed. Also, the oil will end the use of the brake on that side from contamintation. My drum was full of oil when I fixed a similair problem on my 4Runner.

I'd really suggest getting to the bottom of the problem ASAP, wether on your own or with a shop's help.

My 2 cents.

 

Yes I think your right. Did you do your own work or have the shop do it? I saw a thread of a guy who replace his Axle seals on his own.

 

Its pretty easy. Probably a good idea to replace the bearing if you are already working on the seals.

https://www.yotatech.com/~corey/tech...m1_oilseal.htm

Take it somewhere with a press to get the old one off and the new one on.

 

I did all the work myself except for pressing on the new bearings. Not that hard of a job, might take some time if it is your first project.

Good time to do a rear brake job as well.

I bought the new bearings from Toyota, hoping for the best quality... but you might find better suggestions on this board if you search or ask.

 

When you say take it some where, are you saying once i get the thing apart is there a section of the axle I can take in and have them get it off? Or are you saying take the whole truck?

 

This not my first job. But i would say, maybey the biggest ive done.
Thanx to this site. I have done every thing from basic tune up to replacing the radiator, O2, fuel filter, Even painted my interior black and Hurculine on my 87. I love my trucks. Thanx to this site and you guys ive been able to save enough money to keep them running right.

 

If your low on break fluid that can be a sign that the fluid your seeing is comming from a leaking slave cylinder.

 

I think pulling the axles your self sounds like it is within your ability. Not much more involved than a rear brake job.

Then, take the axles to a machine shop, or anywhere really that has a press. Probably best to find someone with a little axle bearing RR experience.

You'll save a lot on labor this way, and be able to add to your growing list of mechanical accomplishments.

 

Yea, thats what i was hoping. I know how to replace a rear wheel Cyl. But unfotunatly...I dont thingk thats it. The brake fluid is not low. And....I think the substance is a little oily for break fluid. thanx though. I put it back to gether and let my wife be on her marrily way. I'll pull the wheel and check it again later this weak and see if it has stoped.
Although, I did pull the lip back frome the wheel Cyl. and brake fluid came pouring out. Is break fluid suppose to come out of those that easy?

 

Yes, Will do, with further inspection. Still not sure if its the Rear wheel Cyl. Do to the fact of how much fluid came out of it when I pulled the lip back.

 

Not really sure of the "lip" you are refering to, but I will mention that my rear drum was full of gear oil when my axle seal went.

 

The rubber on the end of the Wheel Cylinder. I pulled back to inspect. and brake fluid came pouring out. Im going to have to just take it for a good drive as soon as i get a chance and the pull the drum off again and see if it happens again. Like i said. Im hoping its brake fluid and not diff. oil. thanx for all your help. I will update when I can check it out. Bryan