Fluid for MC Brake and Clutch?? Synthetic--REgular

[Bruce_B]

I've got a new clutch and brake MC. The clutch line and slave are also new - might use synthetic fluid in that.

I'll be using Castrol DOT4 for the brakes, since those lines are all existing ones. Is there a way to 'rinse' them out so I can use synthetic all around?

 

[walshja]

I believe the synthetic and non-synthetic fluids are compatible with each other.

you should have no problem mixing the 2

joe

 

[Bruce_B]

Just came across this information while researching my own question.
Came from gerardsgarage.com (great web site):


This tip comes from Joe Way of Sierra Specialty Automotive

Most modern brake rubber is made of EPDM, and there is definitely no problem with it and silicone. The currently available Spridget rebuild kits, packaged in the clear plastic bags with the white labels, are made by a British company called Nelson-Stokes using a proprietary rubber compound. So far as I know, there is no problem with their rubber and silicone.

The issue is that silicone fluid is not nearly as good a lubricant as glycol fluid. In a brake system this is not really a problem since once the system is bled the pistons move only a fraction of an inch at each application, and the applications are relatively infrequent. But a clutch system is of a type sometimes referred to as "long-travel" because the pistons travel through their full stroke at every application, and the clutch is typically used much more frequently than the brakes. So there is a LOT of piston movement in the clutch, and the poor lubricity of silicone will cause accelerated wear of seals, bore and pistons.

Silicone is specifically NOT recommended for clutch systems, and there is of course no way to separate the two systems in a Spridget dual cylinder.

 

[Gearhead]

do your self a favor and just stick with Castrol brake fluid I believe its called Castrol LMF you can't go wrong with it

 

[Bruce_B]

Gearhead...that's what I always use...every now and then I fall for
the advertising!!...Castrol it will be.

thanks all.