thoroughly clean out all the brake system and switch to Dot 5. Less problems with moisture absorption. Best thing to do to keep brake maintenance to a minimum.
Completely disagree.
Dot 5 is silicone, once you switch, it is a one way decision, silicone can't be dissolved with anything, is very tenacious, and can never be completely removed from a system once contaminated with it.
No, silicone doesn't absorb moisture. But, the system still gets moisture inside it through permeable seals, and collects in low areas. Unless you have a low point system drain, the only way to remove it is to overhaul the system at the same frequency regular DOT3, 4, or 5.1 fluid changes are preformed. With the DOT3,4, and 5.1 fluid absorbed moisture is removed during the fluid change. So, you only change the fluid, not overhaul the system.
DOT 5 does NOT minimize brake maintenance, it only changes what has to done. It still has to be changed periodically, and requires a system overhaul when this is done. If you keep the machine in a temperature and humidity controlled environment, then you can extend the brake fluid change and overhaul intervals.
Dot 5 is more compressible than the other DOTs, which results in a slightly spongier brake lever. (some do not notice this, though)
The biggest benefit of DOT5 is, if you are sloppy with the fluid and splash it on paint, it won't dissolve the paint.
For wingman:
DOT4 has a higher temperature tolerance than DOT3. The heat tolerance is normally a requirement at the caliper where most of the heat is generated. So, the master cylinder transplant was labeled primarily for the needs of the caliper, not necessarily the needs of the master.
Still, I believe the SOHC4 caliper seal is compatible with DOT4. And, to be consistent with labeling on the master and to avoid confusion at future top ups, use the DOT4.
NGK makes ignition wire splicers (NGK J-1), so you can add new wires onto the stubs of the old wires near the coil. There have been prior threads about this.