[daven1256]

I had my '68 four piston brake calipers stainless steel sleeved by Vette Brakes in St. Petersburg, FL many years ago and then had them re-built by Vette Brakes again two years ago. They've been on the shelf since then.

I've just finished re-doing my entire brake system and every component is either new or rebuilt original parts. I am ready to add fluid to the system and still on the fence as to whether to go with silicone or DOT 4.

I started wondering what Vette Brakes might have lubricated the sleeves with during the recent rebuild and thought, if they used DOT 3 or 4, would it contaminate silicone fluid if I chose that.....or vice versa.

I called Vette Brakes to ask then that question and they apparently have gone out of business so I'm out of luck there.

So my question is: Would I be safe with either DOT 4 or silicone not knowing what they used during the rebuild? (If they used anything at all)

Maybe I'm overthinking this.

Thanks.....Dave

 

[X-77 keith]

I would think that if you used silicon , by the time you bleed the system, it will be clear of the possible dot fluid.

 

[Larger Dave]

If everything is new I would go with DOT 4. Not enamored of DOT 5, due to poor pedal feel. Silicone has the advantage of not being hydroscopic but how often do you drive through puddles in the rain with your Camaro?

Big Dave

 

[Just 1 More]

I don't know for a fact but I have heard that the silicon fluid will make the pedal spungy

 

[X-77 keith]

I run silicone in my Camaro. Pedal feels great to me. All stock components, just new/rebuilt. Been running it in the circle track cars for years.

 

[Mike_S]

I'm running DOT5 and have good breaking performance. My calipers were too rebuild by Vette Brakes in the 80's. The only thing I had to do recently (2018) was hone the bores to stop leakage from sitting for 10+ years before I replaced with a new set of seals and pistons during its recent restoration.
If they used DOT 3 to assemble the calipers (very likely) then it was most probably when the parts were installed and the fluid was used as a lubricant. I'm sure when you fill the system with whatever type you decide, it will be more than flushed during the bleeding cycles.
The nice thing about DOT 5 is there always seems to be a minor leak that needs attention when doing a complete brake system overhaul, especially on a new restoration, and DOT3 will mar the paint surfaces.
Mike

 

[dyno jonn]

Brake rebuilders quite likely used some type of assembly fluid that is not brake fluid. All major brake parts companies (Wagner, EIS, Raybestos etc) sell some type of assembly fluid.

nbsbrakesupplies.com.au/technical-information/why-you-need-to-use-assembly-fluids

 

[allanjs]

Back in the day when I did this for a living we used assembly fluid as Jon said.

 

[Lonnie P]

Never had a problem with silicone fluid, either from pedal feel or brake fade.
My Camaro has been like this since '93.

I also have seen wheel cylinders go bad from regular brake fluid in cars that never went out in anything but beautiful weather.
I just redid the brakes on 2 of my other cars due to wheel cylinder corrosion, after sitting in a climate controlled garage.... Silicone this time.

 

[scblucam]

I have run DOT 5 for years with no problems and good pedal feel with manual brakes.

 

[daven1256]

Thanks for all of the replies....

I had researched the brake fluid choice a while back and had my mind made up to go with Castrol DOT 4 Advanced Performance Series. I understand this is the new name for the old Castrol DOT 4 LMA (Low Moisture Affinity). That was a fluid that JohnZ had recommended but he also said you need to flush it every two years.

Now that the time has come, I'm only re-thinking my choice because of the damage that DOT 4 can do to paint. With all new lines, I counted 21 total line connections which is 21 potential leaks. This car will be a fair weather driver but everything is painted really nice and now I'm starting to get the willies about possible damage to the paint.

I just have to make up my mind but from the answers given here, it looks like I should be OK with either choice regardless of what Vette Brakes might have used as a lubricant.

Thanks again.....Dave

 

[davidpozzi]

Silicone fluid is more compressible, so it's always going to be lower performing than regular fluid. I've had several friends try it and switch back. Most of my friends run track days and autocross so they need proper pedal feel and confidence in their brakes. If you don't ask as much of your brakes, you may not have any problems.
Is there any manufacturer who uses Silicone fluid?

 

[Vega$69]

DOT 5 is used in most new cars.

You can also use DOT 5.1 which can be mixed with other fluids.

 

[bilodeaulynn]

Not trying to start an argument, but what new cars come with DOT 5?

20 years ago I was rebuilding brakes on my 1983 745i. It was one of (if not the) first production cars with anit-lock brakes. Even my 83 Ferrari didn't come with ABS.
The U.S. market bimmer 7 series did not have anti-lock brakes. I was considering DOT 5, but all my research indicated it should not be used with ABS.

Is anyone even making a car without ABS today?

Just curious.

 

[Vega$69]

https://www.hemmings.com/blog/2013/...different-about-them-and-why-should-you-care/

 

[dyno jonn]

https://www.hemmings.com/blog/2013/...different-about-them-and-why-should-you-care/

We have no need of facts when arguing about facts.

 

[ilikeike]

I looked into it when I filled my completely new brake system,

I guess if you had a car that was going to sit around a lot like some classic cars, or had the same fluid in it for years like a daily driver and wanted looong life, then silicone fluid might be a good choice ,since it doesn't absorb moisture, not harmful to paint...

I considered DOT4 ended up just getting a case of Wilwood 570, I did't read about the 5.1 fluid until after.


"Wilwood does not recommend using DOT 5 fluid in any racing applications."

 

[bilodeaulynn]

First, I wasn't arguing. I thought I made that clear. I was surprised to see that statement. Secondly, if you choose to believe one line in a magazine article from 2013, that is your choice.
The Hemmings article doesn't name one manufacturer using DOT 5 from the factory. It simply states: "DOT 5 is silicone-based brake fluid and is used in most new cars today." I would have been VERY surprised to find out that BMW and MB used DOT 5. Despite what some folks state (such as "I have used it for years, and don't notice any difference in pedal feel") I believe it is clear that it IS more compressable than DOT 3 or DOT 4. Maybe not a lot, but again, I would be surprised to see MB go to it because of that reason.

I was curiouos to see which manufacturers used it. Had never heard of one. I actually researched the manufacturer's use of brake fluid type as of 2018.

Here is what I found, according to the owner's manuals for each brand:

Honda: DOT 3
GM: DOT 4
Ford: DOT 4LV
Mopar: Mopar DOT 3, but DOT 4 is acceptable
Mercedes: DOT4
Toyota: DOT 3
Hyundai: DOT 3 or DOT 4
BMW: DOT4 or the LVDPT4

I realize there are a few other manufacturers, but I got tired of looking.

If I am wrong, it is no skin off my nose. Just asking for facts.

 

[Vega$69]

my 2015 Denali uses DOT. Don’t know what new cars Hemmings was referring to.

 

[Vega$69]

IMO this explains the different DOT brake fluids pretty well

https://www.epicbleedsolutions.com/resources/faq/difference-between-dot4-and-dot51-brake-fluid/