General TR Dot 4 Brake Fluid

[KVH]

I just read a long series of comments/a blog about synthetic Dot 4. A number of folks say you can’t use that Dot 4 without first replacing wheel cylinder and master cylinder seals with non-rubber composition, and even then I should expect to be addressing leaks. What? Really? Why bother? Shouldn't we just hunt down a non-synthetic Dot 4 if it exists and can be found.

 

[dklawson]

Would you post a link to the blog you are referencing?

 

[TR3driver]

_All_ DOT 3 and DOT 4 are synthetic and always have been; they aren't refined from petroleum. The reason some say "synthetic" on the can is just marketing hype, to get you to pay more for them.

See (for example)
https://www.pegasusautoracing.com/productselection.asp?Product=3308

"Remember that the internet is free speech, not necessarily accurate speech, this note included."
See https://www.tfes.org/

 

[LarryK]

Used to be DOT 3 was used in the US domestic cars for the use of neoprene seals in brake systems. DOT 4 was used in European cars because of rubber seals. I don't think it matters anymore. I have always used the Castrol DOT 4 for everything. Bought a newer Rover and it says use synthetic DOT 4 and showed a black Castrol bottle. Went up to Ford dealer and asked for a bottle of synthetic DOT 4 as Raptor systems are close. Parts guy said they don't use synthetic. So I ordered in new bottles of Castrol. Then I looked at one of my old white bottles and it too said synthetic. Well, went to Advance Auto and there was Firestone synthetic DOT 4. DOT 4 has a higher heat tolerance and moisture control. For racing the Ford truck brake fluid has a really good heat tolerance.

 

[KVH]

Yes I’m good with Dot 4 as well. I was reading too many disparate complaints, stories and woes about isolated experiences and a lot of confusion between synthetic and silicone. MOSS has a good article in the subject.

Gosh, I’ve been absorbed in other matters and it’s sinking in that Blaine Graham retired. I’d been learning from him for a long time. And from many more here, and you know who you are. Keep driving TRs.

 

[martx-5]

You mean the earth ain't flat??

 

[TR3driver]

You mean the earth ain't flat??

At the risk of sounding like a former president, that depends entirely on what definition of "flat" you use.

Merriam-Webster gives

and

So by those definitions, the earth is pretty near flat!
:^)

 

[sp53]

It is flat; how else are you going to have horizontal? Do you think everything will return at the finest infinitesimal angle from infinity to go full circle?