Honda CB750 Sandcast

Silicone brake fluid.

toycollector10

  • Newbie
  • *
    • Posts: 37
    • View Profile
I was on some forum or other and I can't remember what one it was but it was CB750 related. Everyone was saying use silicone brake fluid. Non hydroscopic and it will last forever. Well, old dumb##se here decided to use it. It seeps out of EVERY join in the brake system. Right down to going past the O ring that holds the piston so the crap goes out onto the brake pad on the left hand side. This was a 100 point restoration of the whole front brake system right down to black anodizing on the splitter. I despair at my own stupidity sometimes. This isn't the first time I've seen stupid posts on bike forums. For example Q: My bike runs like crap. A: Tear those carbs down right NOW!!! Rant over but hopefully someone will learn from my mistake Peace out.


hondasan

  • Administrator
  • Sr. Member
  • *****
    • Posts: 378
    • View Profile
125,000 miles of use in my rider sandcast without a problem (or ever even changing the fluid over a thirty year period). Two 400/4 Honda's each over 100,000 miles now using silicon DOT 5. Every other one of my bikes from 350/4 - CBX 1000 - VFR750 - CB1300 - Z1B plus maybe thirty others using the same.

Not one problem relating to leaks, seal swelling, etc. And if it gets spilt on the paintwork, no problems there either.

The brand I use is  Automec - works for me - unfortunately therefore no basis to suggest why you have had a bad experience with it.

Chris R.
Chris R.
302/338


kp

  • Administrator
  • Hero Member
  • *****
    • Posts: 1801
    • View Profile
Toy, I use dot 5 in all my machines and never had an issue. First thing though is you have to strip the entire braking system and clean everything of the old  fluid. I replace all the  rubber components with new kits and clean the lines using soap and hot water. If you don’t do that then you’re in trouble.
When I have everything spotless or replaced seals will I fill with the new fluid
The only issue with Dot 5 is the  air bubbles. It takes more time to clear the very fine bubbles that can occur during changeover.  I always use a syringe to fill the system from the caliper up and this generally sees no tiny bubbles and is the best way I know to fill a system
By the way, this is the fluid used by the aviation industry specifically to overcome the water issues of the earlier fluids
Yabba Dabba KP