So I have this '03 Softail that I really need to fix up assuming that the deer incident last autumn only led to minor damage.
It's one of the bikes that came from the factory with Dot 5 silicone brake fluid rather than the regular glycol based stuff. As such, it doesn't absorb moisture but that has me wonder if I still need to change this type of fluid on a regular basis to flush out any potential contamination with water? Not that I've seen any signs of that but I'm pretty new to this whole Harley thing and I've never really owned a motorcycle that takes Dot 5.
They can go flat every few years. I have a 03 road king and it doesn't like sitting for extended periods of time and will get spongy. I would just plan on doing it. Can't be too safe with brakes.
Silicone doesn't absorb water, that's true. But it doesn't block it from getting driven into the calipers via the piston seals. The problem there is the water just sits without being dispersed. So, you can get very localized rusting. I know of no set schedule for flushing, and I generally don't do it at all. But, I will every few years go and bleed a tiny bit out of the calipers just to see how the fluid looks and to push out any water that might be there. Rarely do I see anything of concern (particles, water, etc), but sometimes I do.
As long as you're new, you might not be aware of Harley's weird need for caliper cleaning. They are notorious for getting dirt around the caliper pistons causes a small bit of sticking, which leads to spongy lever/pedal and feel. They are especially good at this come springtime. There's no lack of video's showing how to remove the caliper from the fork (no need to remove it from the bike), removing the pads, and then cleaning the piston area with solvent and a toothbrush, and sometimes a bit of cordage to get all the way around the pistons. Then the brakes feel better.
Thanks for both of your responses. The brakes don't really feel spongy yet, but given that I have to muck around with the rear brake anyway (needs a new rotor) I'll check for water and other crud in the system and make sure to clean the calipers.
