Silicone brake fluid thoughts?
Thread Starter
Drifting
Joined: Dec 2007
Posts: 1,634
Likes: 1
From: aurora
Silicone brake fluid thoughts?
I am in the process for complete brake job on my 81 all new parts
And was thinking of using silicone brake fluid as I was told silicone fluid will not attract moisture and with the car sitting though the winter any help keeping the seals good is always good. any thoughts on this and experiences
And was thinking of using silicone brake fluid as I was told silicone fluid will not attract moisture and with the car sitting though the winter any help keeping the seals good is always good. any thoughts on this and experiences
Team Owner
Joined: Jul 2004
Posts: 40,374
Likes: 788
From: Redondo Beach, California
Since I'll never be driving my 68 too much and given that I had an all new dry brake system, I decided to use silicon. No problems.
There's been just a ton of postings on this forum about DOT3,4 and DOT 5 silicon. All of these "DOTs" will work, DOT 5 gives you the opportunity to avoid rusting inside the brake lines and components. Also, DOT 5 doesn't harm paint.
The insides of my original 68 brake lines and calipers had a lot of rust corrosion. The brake lines were lined inside with a reddish-brown gel like substance. Also, due to rusting, the original calipers all leaked.
My new brake system is all stainless steel (brake lines), stainless steel lined MC and aluminum calipers (SSBC).
There's been just a ton of postings on this forum about DOT3,4 and DOT 5 silicon. All of these "DOTs" will work, DOT 5 gives you the opportunity to avoid rusting inside the brake lines and components. Also, DOT 5 doesn't harm paint.
The insides of my original 68 brake lines and calipers had a lot of rust corrosion. The brake lines were lined inside with a reddish-brown gel like substance. Also, due to rusting, the original calipers all leaked.
My new brake system is all stainless steel (brake lines), stainless steel lined MC and aluminum calipers (SSBC).
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Since I'll never be driving my 68 too much and given that I had an all new dry brake system, I decided to use silicon. No problems.
There's been just a ton of postings on this forum about DOT3,4 and DOT 5 silicon. All of these "DOTs" will work, DOT 5 gives you the opportunity to avoid rusting inside the brake lines and components. Also, DOT 5 doesn't harm paint.
The insides of my original 68 brake lines and calipers had a lot of rust corrosion. The brake lines were lined inside with a reddish-brown gel like substance. Also, due to rusting, the original calipers all leaked.
My new brake system is all stainless steel (brake lines), stainless steel lined MC and aluminum calipers (SSBC).
There's been just a ton of postings on this forum about DOT3,4 and DOT 5 silicon. All of these "DOTs" will work, DOT 5 gives you the opportunity to avoid rusting inside the brake lines and components. Also, DOT 5 doesn't harm paint.
The insides of my original 68 brake lines and calipers had a lot of rust corrosion. The brake lines were lined inside with a reddish-brown gel like substance. Also, due to rusting, the original calipers all leaked.
My new brake system is all stainless steel (brake lines), stainless steel lined MC and aluminum calipers (SSBC).
Dot5
Instructor
Joined: Jun 2006
Posts: 104
Likes: 0
From: Missouri City Texas
Dot 5 should be used with some caution. Although it is non-hydroscopic, water entering the brake system will pool and collect in the lowest place...usually the calipers. Also, silcone will make some seals and o-rings soft and cause them to swell. I have read articles where it is not recommended for cars with Disc-brakes.
http://www.gomog.com/brakes.html#Note
http://www.gomog.com/brakes.html#Note
Burning Brakes
Joined: Oct 2002
Posts: 914
Likes: 14
From: Aberdeen, Scotland
Dot 5
I hate the stuff. It doesn't perform as well as DOT 4; causes water to pool as another just said and gives a mushy pedal. Please do yourself a favor and don't use it. There's nothing bad about using a good DOT 4; i.e. Ford Super Blue
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Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
The only reason moisture Pools is because there is a leak. The system is supposed to be sealed, if not, it will leak and you get moisture. The same system will either get a pool, or emulsified fluid/water. Rebuild it right and No problem
Le Mans Master
Joined: Apr 2000
Posts: 5,202
Likes: 10
From: cincinnati ohio
St. Jude Donor '09
I switched to silicon fluid years ago when I installed a complete new brake system. Since then I chased a spongy inconsistent pedal.
I know there are a gazillion people who run it with no problems, but when I went back to DOT3 fluid the solid pedal came with it
I know there are a gazillion people who run it with no problems, but when I went back to DOT3 fluid the solid pedal came with it
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
I've never used silicone brake fluid as I've heard about the mushy pedal. I've used Castrol Dot 4 for many years. It has less affinity for water than Dot 3. I flush it every 2 years or so. Just my 2 cents. 
Pro
Joined: Aug 2005
Posts: 704
Likes: 2
From: Cincinnati OH
I am in the process for complete brake job on my 81 all new parts And was thinking of using silicone brake fluid as I was told silicone fluid will not attract moisture and with the car sitting though the winter any help keeping the seals good is always good. any thoughts on this and experiences
And was thinking of using silicone brake fluid as I was told silicone fluid will not attract moisture and with the car sitting though the winter any help keeping the seals good is always good. any thoughts on this and experiencesTheMongoose
Race Director
Joined: Jan 2000
Posts: 13,015
Likes: 2,260
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
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2017 C2 of Year Finalist
I did my complete beake system about 10 years ago and used silicone at the time. It worked perfectly with a solid hard pedal. It's been opened up at various times over the years (body off the frame etc) and it was always a simple matter to bleed it and get pedal back.
If it's spongy..you've got air somewhere. Mine sits a lot in the *off season* too and again, never had an issue with leakign seals.
I'm still using the stock brakes and they stop me from 140+ mph at the track just fine.
JIM
If it's spongy..you've got air somewhere. Mine sits a lot in the *off season* too and again, never had an issue with leakign seals.
I'm still using the stock brakes and they stop me from 140+ mph at the track just fine.
JIM
Melting Slicks
Joined: Aug 2002
Posts: 3,334
Likes: 4
From: Midland TX
I replaced my brake calipers with ones from Muskegon Brakes. They sent silicone fluid with the new calipers so I used it. Take your time filling the MC - don't get bubbles in it. I used a Mity-Vac to bleed the brakes. Again take your time. They say it is hard to get bubbles out of the fluid.
My brake pedal is very firm. I've never had any problems with a mushy pedal.
My brake pedal is very firm. I've never had any problems with a mushy pedal.
Le Mans Master
Joined: Apr 2000
Posts: 5,202
Likes: 10
From: cincinnati ohio
St. Jude Donor '09
I even flushed the original silicon with new/different brand on the theory the old was air entrained with no success....can't 'splain it
Burning Brakes
Joined: May 2007
Posts: 945
Likes: 0
From: Ventura California
When my wife and I bought our 930, the previous owner had put silicone in. Not long after, car was pulling hard to the right. Pulled over and the front right rotor was smoking hot. Caliper was sticking. Got it home and completely flushed the brake system. Got the silicone out and put the "regular" stuff back in. Never had the problem again. I could exactly tell anyone why the silicone caused a problem but I suspect swollen seals. Ofcourse, if that's the case, even after changing the fluid you would think they would be shot. Never had a problem since though and they don't leak at all. I suppose it could also be that the previous owner did not have the system completely clean before putting in the silicone.
Racer
Joined: May 2005
Posts: 436
Likes: 0
From: Stavanger
The silicon fluid is more compressable than the normal dot3,4,5.1 fluid. and will give you less pedal feel. so if you are the person who is looking for maximum performance normal fluis is the way to go. if you are looking for less maintainance silicone is the ting. (and another car than a corvette is also the ting :-) )
Le Mans Master
Joined: Mar 2004
Posts: 7,473
Likes: 1,495
From: Little Rock AR
There is a lot of 
available everywhere on this subject. I would suggest you get a copy of the SSBC brake book, a large C-clamp and a Motive Products pressure bleeder before making your decision. You will need this stuff regardless of the fluid used. The book is very inexpensive and will tell it to you straight. This will also clear up the misconceptions that are floating all over the place. The Motive Prioducts pressure bleeder should be in any Vette owners toolbox and costs less than $75 or so. WELL worth the cost. 
Trust me on that.
-Mark.
DOT-5 in all my old cars.
available everywhere on this subject. I would suggest you get a copy of the SSBC brake book, a large C-clamp and a Motive Products pressure bleeder before making your decision. You will need this stuff regardless of the fluid used. The book is very inexpensive and will tell it to you straight. This will also clear up the misconceptions that are floating all over the place. The Motive Prioducts pressure bleeder should be in any Vette owners toolbox and costs less than $75 or so. WELL worth the cost. Trust me on that.-Mark.
DOT-5 in all my old cars.