Rear axle seal and mebbe bearing module

Hey guys,

So I drove the 4runner to our place in Florida from Montreal with a noisy rear drviers wheel. Npoise was atrocious when braking, like metal to metal. Ended up overheating the rear axle seal (oil all over the driveway) and the dash is lit up. I'm guessing the rear axle bearing housing sensor is fried.

I don't have a very extensive tool list down here, compared to up north. I youtubed it https://www.youtube.com/watch?v=8ykU0nDiRkI&t=64s
and think I can pull off the repairs with the tools that I have down here. Wondering if the rear axle ABS sensor is wasted, or just needs cleaning

 

Did you find out what was causing the noise? Was it overheating brakes?

 

Got it all apart after watching the video above. Couple neat tricks in there, such as trimming the brake hose bracket, which allows the removal of the caliper and line without disconnecting the hard line from the hose.
As well, leaving the parking cable attached and removing the bolts that hold the three clips which hold the parking cable up against the frame.

The inner side of the rotor was worn to about an 1/8". I'm guessing that the caliper was partially stuck. the brake pad on the inner side was down to metal and so very badly overheated. The heat took out the caliper piston boot as well as wasting the piston face and sides.

Off to Toyota tomorrow for a new seal and drivers side rear caliper. I'd already ordered front & rear Power Stop drilled/slotted rotors and carbon-fibre ceramic pads, they should be in on Tuesday.

I also want to pick up a new ABS sensor, though it doesn't look like mine melted or anything. But the dash was lit up for a reason, so I'm not sure if I should pick one up. If it's not expensive, I probably will buy it and change it out to be certain. Really don't want to be working on this any more than I have to LOL

 

That’s awesome you just tore into it! It’s nice to know it came apart pretty easily.

Coulple of questions and comments…

-What dash lights turned on?

-Do you think the heat affected the wheel bearings?

I’ll mention this experience on the off chance it applies. I have a buddy with a jeep that recently had a sticking caliper and cooked his rotors and pads His ABS light came on, and we suspected the heat boiled the brake fluid and maybe air got into the abs pump…not sure if that was the reason for the light however.

Here’s the really interesting bit… Why did his caliper stick? At first we thought it was the caliper itself, but the new caliper also stuck and blued his new rotors. We traced the cause down to the flex hose coming off the caliper. It would hardly let any fluid through it when standing on the brake pedal when the bleed valve was open. Sometimes these rubber hoses will break down internally due to age, or if they have been excessively flexed in the past. Once debris starts coming off the inside of the hose, it restricts flow, they become more difficult to pressurise, and when you release brake pressure, the fluid is constricted and the brake doesn’t completely release.
His jeep is a 2017, so we were kinda surprised that the flex hose had deteriorated, but it was plain as day when we removed the hose. When attemping to pump fluid with the brake pedal through the hose, I could barely push fluid through it using the brake pedal. Once we removed the hose, the brake pedal dropped to the floor, and fluid freely flowed from the hard line…just like you’d normally feel when opening the bleed nipple on the caliper.

Keep an eye on the brakes immediately after you replace them. If one side is heating up more than the other side, then check out the flow through the flex hose before you cook your new set of brakes. A IR temp gun is a perfect tool for this. Take it for a short ride and temp both rotors right away.

 

Plus two on keeping an eye out on the brake hose, Have ran into this one previous time in the past (Over 40+ years) on an odd brake issue. the rubber hose had an internal tear that would retain pressure and caused a very similar issue.

 

Update: New rear axle seal, caliper, flexible brake line and ABS sensor installed. Also took the opportunity to install Power Stop X36 rotors and carbon fibre cermaic pads. drained/refilled diff with 75W90 synthetic (yes, I know, Toyota recommends 75W85. If you don't tell anyone, neither will I LOL). Bled the new caliper, took it out for a brake pad bedding. Came back with the brakes feeling good and no evidence of axle leaking so far. Doing front rotors/pads today.

I didn't try to reuse the ABS sensor, but kept the old one as a spare. Blew through the flexible line and it wasn't obstructed/partially collapsed, but happy I changed it nevertheless. It would be at the back of my mind the whole 1700 miles back to Montreal.

Thx to McSpazatron and RumHamRunner7 for their input.

EDIT: All the above was done without any metric wrenches. Managed to pull it all off with just metric sockets and adjustable wrenches for the brake line hose.

 

I found that when the ABS light is on, sometimes it's due to being really dirty or dust covered, in your case I'm guessing you had debris/dirt/oil on your ABS sensor. Glad to hear you got it running again! Maybe clean your old ABS sensor with brake kleen, there must be a test it.

 

Not really dirty, but I was worried that the heat had caused damage to the sensor, causing it to light up the dash. Didn't want to take a chance.
And yes, I'd like to know how to test it, other than swapping out the new one and seeing if a code gets thrown...

 

Congrats! No codes or dash lights? Must be a nice feeling to complete a repair like this “off-site”, so to speak, away from your usual tools. For some reason I figured doing seals on the axle would have been much more challenging, but it looks like even I’d be able to tackle it should the need arise.

I felt bad at first for mentioning my low-probability situation with the flex hose, but now that I think about it, being away from home and doing this job twice would suck…so I probably would have done the same. The caliper locked up for some reason…at least this way you addressed any possible cause right off that bat, even if the flex hose was an unlikely culprit.

 

I understand the heat concern, as for testing it, someone on here might know how. Good luck.

 

I believe it works on the principle of Hall Effect. So in theory, maybe swiping a magnet past it while checking the continuity might be a test. I'd have to research it a bit..

 

Good idea.