looking to drain and replace the brake fluid in son's Mercury.  thought to be presently loaded with silicone or DOT5...; I want to drain and replace with the regular stuff, not silicone.

any suggestions on the best way to do this? whether or not I should swap it out?

the stuff in the M/C is a bit thick and mirky looking, so I am thinking it should be replaced...

is it a simple drain and refill or are there some significant drain/flush/refill steps to follow??

thanks, Mark

"God Bless Texas"location: Houston,TX

If it is DOT 5, I wouldn't bother changing it to DOT 3 or 4.



A few threads:



http://www.y-blocksforever.com/forums/Topic55645-3-1.aspx?



http://www.y-blocksforever.com/forums/Topic12667-4-1.aspx?


Lawrenceville, GA

Ok, sounds like if I have DOT5 presently loaded, I should probably stay with it...

problem is, I bought the car from a less than knowledgeable chap; only way I have of knowing its loaded with DOT5 is a lable attached to the M/C stating so... don't know how long its been on there, who made the change over or anything else definitive...

Is there some way I can confirm that its loaded with DOT5?

"God Bless Texas"location: Houston,TX

DOT 5 won't strip paint - test in an inconspicuous area.


Lawrenceville, GA

duh!  well my nose was right in front of my face on that question!!

consider me humbled!

"God Bless Texas"location: Houston,TX

Put some fluid on a flat surface, and put a couple drops of water on the fluid.  Silicone won't accept the water, it will bead up like on a freshly waxed hood.  Glycol fluid and water will tolerate each other, actually mix if left sitting a while.

John - "The Hoosier Hurricane"

Dot 5 is usually purple

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

If it is not siclicone, I would switch to it.

From the description of the fluid, it sounds like it's contaminated and needs to be changed out.  Dot 5 fluid does a good job of staying clean over the long haul if not mixed with any other specification brake fluids.  Flushing the system and insuring all the old fluid is out of the system before refilling it would be prudent.

Lorena, Texas (South of Waco)

I am changing back from silicon to conventional. Silicon leaks past the wheel cylinder seals, makes replacement of the brake light switch mandatory on a yearly basis. As far as I can see it buys me nothing.