I’ll probably repeat it a bah-jillion times but it is worth repeating: if you are bleeding hydraulic brakes, mineral oil and DOT fluid ARE NOT INTERCHANGABLE! It’s kind of like when they tell you not to put diesel in a regular gas engine. And in this case, super faulty braking can be the result. Thing is that DOT fluid is classified by number, from 1 to 5. The higher the number, the more head the fluid can resist therefore helping the braking accuracy when you are super grinding on the brakes, especially you downhill folk.
Like Shimano, Magura brakes DO NOT USE DOT FLUID. DON’T BE A NIMROD! YOU’LL SCREW UP YOUR BRAKES!
Okay, so the bleed procedure is normally from caliper UP TO the lever. You’ll want to remove your wheel.
DON’T GRIP THE LEVER WHILE THE CALIPER IS NOT ON THE ROTOR! Doing this will cause the pistons to too far and it’ll take a hell of a while to get your pistons functioning again. All you have to do is once you’ve got the wheel and the brake pads out, slip a caliper block where the pads were so that you can keep the pistons well separated. If you don’t have one of these blocks, use a 10mm hex wrench.
Remove the bleeding screw and attach the prepared syringe with mineral oil. Make sure there are no air bubbles in the syringe. The point of this process is to get the dirty oil and the bubbles that may be stuck in different points of the mechanism out, both of which can cause shoddy braking so making you’re not putting in more bubbles will mean less work for you.
Up top, make sure you turn the reservoir level so that when you take off the lid, you don’t dump all the fluid on the floor or on your bike. If you have a mechanism like the one in the video, use a syringe.
Proceed to depress the syringe slowly and then retract. If you have an open-top reservoir, depress until the liquid is about level and right before overflow. Do that several times to make sure you get all the bubbles out.
Give your lever a squeeze and see if there is resistance. If not, keep at it. Once you get the proper resistance, close up the reservoir and carefully clean it. Do the same with the bleed port at the caliper. Use a rag to catch the oil that may come out when you remove the tubing.
There are some recommendations I would make in addition to those the guy in the video made: 1. Wear gloves; 2. Don’t use the same rag that you used to clean the caliper of oil, to hold the brake pads (they can get contaminated and lead to faulty braking) and; 3. Clean off everything of mineral oil BEFORE putting the brake pads in and the caliper on the frame.
