[Shop-talk] Silicone brake fluid

[Bob Spidell]

I have heard Dawn Dish Soap--the 'miracle' detergent--will remove 
silicones and allow for painting.  No personal experience, however.


On 5/16/2020 8:46 AM, Eric Russell via Shop-talk wrote:
> I would clean them out. It may not be required but now would be the 
> best & (only?) opportunity.
>
> Alternatively, suggest the use of DOT 4. It is 'regular' brake fluid 
> (even though the label on the can will likely say "synthetic") with a 
> higher boiling point than DOT 3. And it'd be totally compatible with 
> DOT 3.
>
> DOT 5 (true silicone) has two advantages. 1) it won't eat at paint if 
> spilled/leaked and B) it doesn't absorb H2O. However it is more 
> expensive and, despite not absorbing water it should still be flushed 
> every few years. And if it is spilled/leaked will make repainting 
> problematic. (I've heard some painters won't touch a car that has been 
> 'contaminated' with silicone). Since DOT 4 is not expensive, regular 
> flushing every few years is not so dear. And DOT 4 is readily 
> available should one need a supply while away from home. May not be 
> true with DOT 5.
>
> Eric Russell
> Mebane, NC
>
> On 5/16/2020 10:06 AM, Robert Nogueirao via Shop-talk wrote:
>> I’m helping a friend rebuild her brake system. All new lines and 
>> hoses. I’ve rebuilt the calipers, brake cylinders and master cylinder 
>> and they are ready to install.
>> Here’s the problem:
>> In rebuilding the cylinders I coated the bores lightly with red brake 
>> grease and DOT 3
>> Fluid.  Now she tells me she may want to go with Silicone fluid.  
>> Does that mean I need to disassemble and wash out all the cylinders 
>> and calipers?
>> Thanks for any answers.
>>
>> Bob Nogueira
>
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