Is bleeding the brakes difficult after installing a new master cylinder? Any tips?

It can be tricky and requires patience. A tip is to use a vacuum bleeder tool, which makes pulling air out of the system much easier. If you don't have one, the traditional "pump and hold" method works well. Always ensure the reservoir never runs dry during the process.

What type of brake fluid should I use (DOT 3, 4, or 5)? Can I mix them?

NEVER mix DOT 5 (silicone-based) fluid with DOT 3 or DOT 4 (glycol-based) fluids. They are chemically incompatible and will ruin your entire brake system. Always check your old master cylinder cap or service manual for the recommended fluid type and stick with it.

I've installed a new master cylinder, but my brake pedal still feels spongy. What else should I check?

If you are certain all the air is bled out, the next most common culprit is an old rubber brake line. Old lines can flex and bulge under pressure, causing a spongy feel. Consider upgrading to a braided steel line. Also, check that your brake caliper piston is not seized.

4 Harley-Davidson Motorcycle Rear Master Cylinders

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Cycle Standard Rear Brake Master Cylinder - 1987-2003 Harley-Davidson XL - OEM# 42456-87C
$118.76

Drag Specialties Rear Brake Master Cylinder Assembly - Chrome - 2007-13 Harley-Davidson Sportster XL
$173.35

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