September 2022 - Rear Brake Master Cylinder Overhaul
As mentioned in last post, the rear MC got stuck and some hard pumping jammed the rear brakes. Had to remove the pads to free up the wheel.
Bought Rear MC repair kit from RE spare outlet, Subha Autowares.
Rear MC Major Kit - 594689/A - ₹ 277.00
The rear MC looked very much familiar.
Dug up old MC from Duke and it's exactly the same. RE charges ₹ 1300 for that. Dominar part was ₹ 740.00 (and KTM part was even cheaper with the reservoir per
@JingalalaHoe).
Contents of the kit.
To start off, have to remove the circlip.
Then push out the piston.
Once it budges out, it can be pulled out with pliers.
The complete piston setup.
Next, removing the sleeve. Since we have a fresh piece in the kit, we can break it off.
Then, take out the old O-ring.
After taking everything out, clean up the body and check for blockage.
My best friend.
Ready for install.
The most important part of the kit, the silicon grease.
The first to go, the O-ring,
Bathe it in grease,
and install.
Then the sleeve.
Grease it and push it in.
An 11-mm socket head fits perfect, and it goes in without much effort.
Perfectly seated. Make sure it is deep enough for the circlip.
Assembling the piston.
Parts in order, first, the brass washer,
then the diaphragm.
Diaphragm orientation.
The retaining washer for the spring.
Spring over top. Assembly complete and ready to go in.
Got to adjust the diaphragm to fit in the hole. When it's working properly, it tends to budge out without the clip. Push it in and it should return freely.
Install the circlip to secure it in place, and this completes the repair.
Clean and replace the rubber cap, not available with the kit.
Connect to the pedal and check for action. Can connect reservoir line and check the working before final install, if need be.
Banjo bolt and crush washers. Ideally, replace washer whenever removed. As usual, forgot getting them and retained old ones.
Once all installed, fill up the reservoir and start pumping. Plugged in reservoir hose after removing the air in line and pumped a few times till fluid came on the braided hose side before installing to ease up things. Make sure not to spill fluid anywhere.
Bleeding the rest of the line would be easy. Didn't click these as hand was dirty/busy.
.
Once complete, make sure the fluid level is right.
Set the diaphragm in the cap.
and done.
Install the leg guard.
Done.
