Here We Go Again:DOT 5 Brake Fluid Warning>":Will Void Warranty"

[Larry E.]

Just got my order in from Corvette Central; Part #192030(See Below). It is 65-66 Standard M/Cyl. Cap w/clamp and
w/Gasket. Wanted a spare to add to my parts bin. Here is how the warning tag reads>

Using DOT 5 Brake Fluid "Will Void Warranty". Changes in Chemistry May have adverse effects on Brake
Rubber as per EPA rule.

https://www.regulations.gov/document/EPA-HQ-OPPT-2009-0767-0031

[Larry E.]

Re: Here We Go AgainOT 5 Brake Fluid Warning>":Will Void Warranty"

Kinda hard to follow this but does this mean the rubber gasket that seals the Master Cyl. Cover
will not work correct if using DOT 5 ?? Do we now have to start looking for different gaskets
for the cover?? Not sure what harm this will do but what do I know?? Larry
OR is this a warning for other rubber parts and not the Master Cyl. Cover Gasket?

[Joe L.]

Re: Here We Go AgainOT 5 Brake Fluid Warning>":Will Void Warranty"

Just got my order in from Corvette Central; Part #192030(See Below). It is 65-66 Standard M/Cyl. Cap w/clamp and
w/Gasket. Wanted a spare to add to my parts bin. Here is how the warning tag reads>

Using DOT 5 Brake Fluid "Will Void Warranty". Changes in Chemistry May have adverse effects on Brake
Rubber as per EPA rule.

https://www.regulations.gov/document/EPA-HQ-OPPT-2009-0767-0031

Larry-------


The regulations you cite apply to, among other things, glycol based brake fluids (i.e. DOT 3, 4 and 5.1) and not silicone based DOT 5.

If the cap gasket is made of silicone rubber, it will not be compatible with DOT 5 fluid. If it's manufactured of EPDM rubber, preferably peroxide cured, it will be compatible.

[Larry E.]

Re: Here We Go AgainOT 5 Brake Fluid Warning>":Will Void Warranty"

Larry-------


The regulations you cite apply to, among other things, glycol based brake fluids (i.e. DOT 3, 4 and 5.1) and not silicone based DOT 5.

If the cap gasket is made of silicone rubber, it will not be compatible with DOT 5 fluid. If it's manufactured of EPDM rubber, preferably peroxide cured, it will be compatible.

Joe: Thanks for the reply. Since the warning tag was on my package that had only the part above I got to assume that
the cap gasket is not compatible with DOT 5. (Which I use) So here are my questions:
1)If I use this gasket what will happen? Will it brake down and put small pieces of rubber into the reservoir?
2)If not and the only problem is that it will not seal the cap; what then? Air will get into the system?
3)Where would anyone find a cap gasket made of EPDM Rubber?

Anyone with a solution will be appreciated. Thanks>Larry

[Owen L.]

Re: Here We Go AgainOT 5 Brake Fluid Warning>":Will Void Warranty"

I don't think you have anything to worry about. If it reacts poorly to the DOT 5 (which I also use) the rubber will swell and get mushy but I don't see any detrimental effect on safety or contamination to the system. You could test it before installation by putting it in a shallow container with D5 for a week, but I'd think that would be a waste of fluid since I doubt the rubber is silicone and reactive w/D5.

Air won't get into the system without the gasket. Additionally, DOT 5 does not absorb moisture, so exposure to air isn't going to accelerate it's aging like it would D3 & 4.

When I replaced the rubber gasket on my cap, I just bought the inexpensive replacement and didn't give it a thought. I don't think you are going to come across a gasket made of either EPDM or silicone. The stickers seem to be stuck only applied to products from Corvette brake rebuilders and vendors. Buy a seal kit from Raybestos or a caliper/master from O'Reilly's and you won't find that sticker.

[Patrick B.]

Re: Here We Go AgainOT 5 Brake Fluid Warning>":Will Void Warranty"

Larry- You have nothing to worry about. The DOT 5 warning sticker is just an automatic cover-your-ass action on the part of restoration brake part suppliers. We have proven on this forum that the idea from these parts houses that DOT 5 fluid changed and became harmful to brake seals is simply false. These parts houses sold o-ring calipers using o-rings not made from EPDM rubber which is industry standard for brake parts, and these inferior o-rings may fail eventually in DOT 5. Ordinary brake parts other than o-rings presumably come from the established brake part industry and are EPDM rubber. In the extremely unlikely event that the gasket in question was made of the same inferior rubber as the problem o-rings, it may swell about 10% in 10 or 15 years. Nothing would fall off into the fluid.

As Joe pointed out, the cited EPA rule has nothing to do with Silicone brake fluid, and it appears to be about reporting issues rather than any chemical prohibitions concerning DOT 3, 4 and 5.1 ingredients.