petros

First and foremost, I searched this subject and all I could find was a mis-mash of information that wasn't easily usable.

On to the important matter. About two weeks ago after about 250 miles of driving, my '98 4Runner's brake light went on on the dash under acceleration. First impression was that my parking brake needed adjustment. Shrugged it off, and when I got back into town I pulled up good old Yotatech and found that the brake light turning on could possibly indicate low brake fluid. I checked it and it was about midway between the min and max lines, so I kind of ignored it. The light came on inconsistently in corners, acceleration, etc.

Today after heading out for the morning, the light came on and for the most part stayed on. I looked at the fluid reservoir and it was a bit lower than it was a couple of weeks ago when I last checked it, so I checked for leaks. The passenger rear brake was soaked in fluid, problem found.

I'm a bit lost on how to go about fixing it. I know it's something that can be done at home. Right now I don't know if it's just a leaking brake line going into it (that's not what it looks like) or if the whole brake needs to be rebuilt. I am reluctant to going down to the dealership to buy a rebuild kit if I don't need to do that. Is there something notoriously wrong with 3rd gen rear brakes that causes leaks?

Either way I'll need to bleed the lines, and I'm wondering what the procedure is for bleeding them with the ABS on it or if it's no different than a non-ABS car.

Thanks!

millertime_t1

Go get yourself a wheel cylinder, a new set of brake shoes, a can of brake clean and have at it? ABS bleeding is the same application as any other!

drguitarum2005

i dont know about the dealerships around your area but the one close to me will diagnose the problem for free, regardless of if i have them fix it. i had this problem on my isuzu rodeo back in the day and what it was was that the pads were so worn causing the pistons to stick out so far that they shot fluid out. how do your pads look?

surf4runner

i recommend replacing both sides at the same time.

Ironmike4x4

Good post! Straight to the point diagnostics. That's exactly what it sounds like to me. Now the brake light I am not too sure of without actually looking at it.

rngrchad

Make sure also, that your leak is not a blown axle seal. Hypoid oil could be leaking from your axle into your brake drum causing you to believe what you have is a wheel cylinder leak. Just double check that.

petros

As far as I know differential oil has an odor and feel to it that's different than brake fluid, and all signs point to brake fluid. But that's definitely what I'm here for, to see what else it could be, so thank you. This morning I went out to the truck between classes at school and the fluid level had gone down to just about the minimum level, and the pedal is feeling gutless (press it all the way down to stop completely). But it has no problem stopping. I'm going to stop driving it until I fix the problem, and as of now I'm going to assume the problem is a wheel cylinder. Got some new pads, some brake fluid, and a new wheel cylinder from Kragen and we'll see how it goes when I tear things apart tomorrow.


According to my research, which was limited to the search feature on Yotatech, it seems the light is a sort of warning mechanism for low fluid or brake problems. It would make sense that under acceleration, the fluid level might change by the sensor, and going up hills would do the same. If it weren't for that I probably wouldn't have recognized there being a problem until it was too late.

Thanks for the help!

Oh and for the record, the dealership wanted around $40 for the wheel cylinder rebuild kit, and Kragen had the kit for $12 and a new cylinder for $17. Figured it's not worth screwing around with cleaning the old one out so I just got a new one with a "limited lifetime warranty."

Ironmike4x4

Normally I would think that the light would be an indication your brake fluid was REALLy low. I dunno, mine went down to the low mark and did not turn on a warning until after it went about 1/2" further down the low mark. For cheap toyotparts I would checkout http://1sttoyotaparts.com/

CyMoN

at the same time change out the front pads before adding brake fluid

petros

Well, not a good day. I got my wheel cylinder, new shoes, etc., and went out to replace the cylinder, only to find once I was inside that the problem wasn't the cylinder, it was the axle leaking. Smell gave it away as soon as I had it open. I can't explain the low brake fluid problem except that maybe it was settling in. The shoes definitely had grease on them which is why my braking capabilities were lowered.

When I was at the dealer the other day the parts guy said for the seals in the axle would be over $200 to get rebuilt, just from parts, but "lucky for you this probably isn't your issue." He also made a point to say that the seals are all pressed on, so most likely I would need to get it done professionally.

Is that my only option?

ohio4runner4x4

Got the same problem...:pat: ..picked up the seals a few weeks ago and want to get it done very soon. To buy some time, I pulled the drums and used brake cleaner on them to clean out the gook and took some 60 grit sand paper to the brake shoes....not the best, but it helped and I have been pressed for time! Anyway.....here's the link, courtesy of David (dcrim1), on how to do it....looks pretty cheap to do and doesn't look all that hard

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

YotaFun

I have the same issue myself, on my 97' Runner

But I was told there were and inner and outer axel seal and abearing and that those seals had bust out and need to be replace....

I guess I am confused, is my problem liek yours or something totally diffrent?

Sorry for the highjack, just curious...

petros

The link on how to change the inner seal is very helpful. I did a search on this issue and found that a LOT of people had the same problem with their 3rd gens, and they replaced the inner seal, and for most of them it didn't work. I don't mind doing the work, but I'd really like to know if there are any symptoms that could point me in a better direction. As of now it could be the inner seal, the outer seal, or the bearing, in order of expense to repair from what I understand. So is there anything that I can do to find out specifically which seal is blown?

YotaFun

I hear the only way to find out is to take it apart...

I hear that there is no way of telling it is even blown untill you either
1-completly screw up the rear
2-have the brakes donw and find the problem
3-have your tires changed and find the problem
4-your front brakes go way early...

When I went to ask toyota they told me it would be $1000+ to do the seals and bearings.....
I was like WTF!!!
Then I went to a friend of mine who had done some headgasket work on a car I had a while back (pre-runner life) and he quoted me for seals and bearings for a total of $558+ (for lubs and such)

So yeah.....

Toyota I think should put a recall on this issue....

But there must be somemthing everyone is doing in particualr to blow the seals....

Cause my step dad has way more miles then I do and his haven't blown yet....

petros

One of the things I read here said that if the differential vent/breather is clogged, pressure could build and it could go that way. It's on the top of my list to check.

YotaFun

When I take mine to my friend I am going to go over it with him cause I want to see what is involved and I will check that...

YM13

Yah i have same problem that i'm trying to fix right now...I think what happened was that when i went offroading and drove through some water, the breather was clogged and the pressure blew the seals. I think this happened because the car is at 108,000 miles and it has never been through deep water or mud and the breather has probably jammed. Also, it looks like my leak was pretty recent. (i had been wheeling a week ago) So i'm planning on doing that project this weekend....we'll see how it goes...as for the oil seal and o-ring, I can't find them anywhere for some reason...sorry for the hijack but if anyone knows where to get them please PM me or something..(tried advanced auto parts...they had no clue what i was talking about even after i showed them a diagram and pictures from previous posts)

Jason B

Here is the inner seal removed.


How pretty.

On jackstands:



This was the best write-up I found, but I read them all. This is specifically for models with ABS, which makes a little difference, well, it's just a little trickier to get the inner seal out on models with abs.

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

It wasn't bad at all. I took my time and had a friend help me pull the axel out. I wanted to make sure I kept it real steady when pulling it out.

All the time as spent on cleaning up all the oil soaked stuff, wheel, drums, etc.

Some other tips that worked great.

Make a note of these:

1) "I did find out if you put the new axle seal in the freezer for about 10 minutes, it shrinks just enough to easly slide back in the place of the old one. The seals are very hard to fit back in if you dont do this and they have to go in perfect or you might damage it."
by Jataga

2) "You'll need to bleed the wheel cylinder on that side. That's probably my least favorite part of the job.

You can try gravity bleeding it by just leaving the bleeder screw open and draining into a cup while keeping an eye on the master cyl. to make sure it doesn't run dry. It doesn't drain very fast, but keep an eye on it.
Gravity bleeding usually works, but if not you can have your friend step on the brake pedal an hold it, while you crack open the bleeder to let the pressure out, then close the bleeder, and have your friend let back off the brake. A few cycles of that after gravity bleeding should do the trick.

Don't let the master cylinder run dry and don't let your buddy let off the brake while you have the bleeder open. Either one will introduce more air into the system instead of get it out.
If you're going to be working on your (or a buddies) truck and bleeding/flushing brakes, buy a motive products power bleeder. Its worth it."
by Erik

3) Buy some rubber vacuum caps from Advance auto to plug your brake line after you disconnect it.
7/32in. part # 47392, about $2.



I just had a a friend bleed it at the back when I stepped on the brake pedal. This whole process for the bleeding took 1 min exact, very easy with two people.

petros

Thanks for the tips Jason. We took the axle out this morning and got it all cleaned up, and my dad tried putting the new seal in and managed to mangle it pretty bad. So while I was out I bought another one, and he tried to put it in again, and this time I was there watching him do it. He had a perfectly shaped socket that was just as large as the seal, and he used gentle tapping of a rubber mallet on it, and it just got all bent out of shape again. Kind of frustrating, because the seals at $9 each aren't cheap and we seem to be going through them pretty fast. I need to go buy a new one, but we just don't know what else to do that would work if the last seal was still all bent up. He's getting kind of frustrated too because he's done this stuff many times before and now it's getting to him that he can't finish it. Any other tips on seating the seal?

Jason B

Hmm, did you stick it in the freezer first? This helps.