So here is an odd issue.

Besides knowing NOT to switch between Dot 4 and Dot 5 brake fluid, is there any other reason gelling would occur in the Front Brake Master Cylinder?

My 09 SB just had service at the Dealer. Before you get on to me, I'm a service member currently stationed overseas. All my tools are back in the states so I do not have the ability to care for her myself (primary culprits being my torque wrenches).

I have been informed my front had Gel inside and would cause the front brake to lock up. Being in a hurry, I didn't have time to ask the questions I wanted. And figured I would get better answers here anyway.

Has anyone else heard of this? I have read some mentions about leaking caps, but nothing about gelling (without the switching between fluid types).

 

3&4 are compatible but not 3&5 or 4&5. Clean it, blow it disassemble it, flush & bleed it, and go with 4. Cheaper and performs as well. 5 is silicone base good for higher temps and safer on paint, but is overkill on a Harley unless you are racing.

 

Will certainly get on that.

Problem: To my knowledge the fluids have never been mixed.

The bike was purchased used from the dealer. The bike itself was never out of the hands of the dealer, presumed to be a rental for a bit. I think I probably put more miles on it than anyone else before buying it.

I just wanted to ensure this was not a developing problem from HD. Perhaps a reaction between gasket material and fluid (I'm throwing darts to see what sticks here). Not exactly a brake expert myself, although, it is a pretty basic concept.

 

Never seen it without the mix. Have seen a little emulsion if moisture gets in somehow. As you said pretty basic, so flush it good, bled it good, and get on down the road.