FZJ80 Rear break leaking break fluid (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Aug 22, 2009
Threads
59
Messages
166
The right rear break caliper is leaking break fluid. Is this a symptom of a worn pad or is it likely more serious?
Thank you in advance for you support in diagnosing this. Dan
 
Worn pads won't cause a leak.
Where is the leak coming from?
Around the banjo bolt or from behind the pad?
 
It will depend on where it is leaking from (hose connector, bleed nipple, piston). If it is the piston then you likely have a worn or damaged seal. It is possible that worn pads have allowed a corroded piston to let brake fluid escape past the seal however replacing the pads may not fix that if the seal was damaged. Best to pull the caliper and have a good look. Remove the piston and check for corrosion. If all is good, a rebuild kit is fairly cheap.
 
RC0.jpg

RC3.jpg

RC9.jpg
RC4.jpg
 
👆🏽 This is really not as hard of a job as it looks. Most difficult part is usually getting the piston out.

Piston was no problem....a number of ways to do that easily.

Cleaning the parts was the most work for me and I don't even live in the rust belt.

But I believe strongly that brake parts should be nice and clean before being reassembled/rebuilt.
 
No need to disconnect the brake line. just pop the piston out with the peddle, then just rebuild, then clean off the brake fluid, mount and bleed. bleed a lot just because it is a good time to do a flush and only takes a few extra minutes. Brake fluid should be clear, not green or yellow or white etc.
 
No need to disconnect the brake line. just pop the piston out with the peddle, then just rebuild, then clean off the brake fluid, mount and bleed.

Sounds easy but I can tell you from having done it, you'll want to have the caliper 'in hand'. Getting the boot over the piston can be tricky....not to mention you 'should' thoroughly clean everything....NOT just throw some parts at to get it over with.

Take a little pride in your work and do it right.
 
True you need something to hold the caliper so it isn't hanging, i have a 6x6x24 inch piece of wood and a drain pan on top of it. I clean the caliper before ripping it open. If your pistons are still good. I keep a spare 1 or 2 new ones just in case i find the old ones pitted or otherwise damaged. I slide the boot over the piston before trying to slide the piston in to the caliper. putting the boot on the caliper first has never worked for me. Having spare parts make the job a lot faster. Once you get the new seal in then slide the boot down low on the piston and then the boot in the groove and slip the piston in. let the bleeder out a little and repeat for the other piston. then clean the brake fluid off the whole thing and remount. put pads in and bleed it out.

This year already I have rebuilt two front sequoia calipers, 2 front calipers to a 79 pickup, 3 rear 80 series calipers and I will tell you, if there is any rust around that seal and inside of the boot, you have to stop the rust or you will be back in again soon. If it has gotten too bad, replace the caliper. You can rebuild on the trail to stop sticking but it won't last so be prepared.
 
Indeed. I typically just remove the pads, remount the caliper, and stomp the brake pedal tho. Pops the pistons out to the rotor without shooting them across the garage!
The rear caliper piston is captured by the housing. It won't shoot out if you're careful.
For the fronts I use a wood spacer that also makes quick work of getting all 4 pistons out.
 
True you need something to hold the caliper so it isn't hanging, i have a 6x6x24 inch piece of wood and a drain pan on top of it. I clean the caliper before ripping it open. If your pistons are still good. I keep a spare 1 or 2 new ones just in case i find the old ones pitted or otherwise damaged. I slide the boot over the piston before trying to slide the piston in to the caliper. putting the boot on the caliper first has never worked for me. Having spare parts make the job a lot faster. Once you get the new seal in then slide the boot down low on the piston and then the boot in the groove and slip the piston in. let the bleeder out a little and repeat for the other piston. then clean the brake fluid off the whole thing and remount. put pads in and bleed it out.

This year already I have rebuilt two front sequoia calipers, 2 front calipers to a 79 pickup, 3 rear 80 series calipers and I will tell you, if there is any rust around that seal and inside of the boot, you have to stop the rust or you will be back in again soon. If it has gotten too bad, replace the caliper. You can rebuild on the trail to stop sticking but it won't last so be prepared.

You can also block the piston, then use a regulated amount of compressed air and a rubber tipped blowgun to 'inflate' the boot. Use a dull pick to go around the lip of the boot (fit it to the piston) for a very easy installation.

And you are spot on about the rust, No Bueno! 👍
 
Good video overall but I cringe when I see the spelling for "brake" or brakes" as "break" or "breaks".
 

Users who are viewing this thread

Back
Top Bottom