Moparts Tech Archive
Brake Fluidssilicone brake fluid?
something i never thought of (member mentioned it) was the silicone fluid not making your paint disappear. the instructions that were in the dart i brought (master power brake) state that if silicone fluid is used it voids the warranty. are there any known incompatibilities between this fluid and sealing components?
No problem in my GTS's system. Have had it in there for 3 years now. It's really nice to bleed the brakes now. When you're done, just spray the axle housing/backing plates with Windex, and wipe. Just be sure to let the fluid sit in the master for a hour or two before bleeding. It does have micro bubbles of air that need some time to rise to the surface in the master.
I know someone who made mistake of mixing the two fluids and wound up with a big fix-em-up job.
i'm assuming you're talking dot5 fluid. i use it in my r/t and will use it in my 65 coronet. no problems at all. if you're doing a new front to back system i'd highly recommend dot 5. dot5 and dot 3 will not mix, so flush anything that has had dot 3 in it.
I don't know where people get the notion that DOTs don't mix (I had it too) but e'burger says that they must in order to be saleable and I tend to agree (even though when I put it in my car I flushed out the lines with denatured alcohol and rebuilt everything except the p. valve). I have both and I am going to mix them in a glass and see what happens -- I will report back. Kim
I've been running 5 for just over a year now I guess. No problems, and stiffer brakes too. Best part is if it ever leaks, it won't hurt anything.
We have a couple models of Hyster lift truck that require DOT5, the rest take DOT3. The factory released a service gram a couple years ago about mixing the two fluids. Basically, it stated that even though it turns into a really nasty looking mess, it will still work. It actually looks kinda like DOT# that has drawn water
To get the benefits of Dot 5 it's important to get as much of the old Dot 3 out of the system as possible.
Dot 3 and Dot 5 will definately mix (it's called "miscability" and they have to be able to combine and be compatable in order to be DOT certified. An analogy would be the difference between 87 octane and 93 octane gasoline; You can mix them obviously.
I've used in my last 2 cars with no issues!!! It'll stop a 3350 131MPH street car.
In some systems the DOT 5 is not compatible with the rubber and dissolves them to a gooey mess. We no longer use it at my shop for this reason.
if you were flushing the systems with alcohol,that is where the gooey mess would originate.
I've done brake jobs off and on for 30 years, and alcohol is the prefeered solvent for cleaning brake systems. Flushing the system with alcohol is the best way to insure there is no residue of dot3 left in the system. Alcohol will evarporate as the brake system is not hermetically sealed.
My understanding of DOT 5 is that although it has a higher boiling point, it has no inherent lubericating properties. I would not mix them. DOT 3 mixed with DOT 5 is not DOT 4 !!! Use one or the other. I will stay will DOT 3 and keep it off my paint!
I've had DOT5 in my Road Runner since 1995 with no problems yet.