DOT 5 - Is this new to anyone else?

[Fred Y.]

Re: DOT 5 - Is this new to anyone else?

I'll be watching for that report Tom. The 69 dollar question is that our cars are surely not ABS cars. Still a lot of gray area here. Obviously it's a chemical issue with the seals I'd say, but why is this so tough to tackle with all the technology we have today?

[Larry M.]

Re: DOT 5 - Is this new to anyone else?

If you go to the CSSB Inc website where this warning is posted, you can see firsthand their pictures of brake seal rubber deterioration from use of DOT 5 fluid. This may or may not have been from folks using one single DOT 5 brand............but regardless, they are now saying to stay away from DOT 5 for both safety and warranty reasons. I would like to see them run the same test with the fluid JoeL or I still have.

My personal feeling is that the DOT 5 "of old" was fine, but more recent formulations (perhaps from off-shore sources) have proved problematic and random. Take that for what it is worth. Since DOT 3/4 is the "standard" fill by all automakers, they are very careful to make certain that any and all (new and old) brake rubber seals that they use and sell will work with it..............and there is enough used and sold here in the USA that any problem would be national news and a major recall.

DOT 5 is different, and not used that much by the general public. It is also costly, and likely no longer made by many of the original, major USA chemical companies like Union Carbide and DOW. Both companies have undergone major buyouts and mergers and changes over the last 20 years including their product lines. That is why if you buy DOT 5, buy it from a brake company that still sells it.....not just any store. If there were issues with their brake seals they would no longer sell this DOT 5 and would find a different source for the fluid that did work.

And since ABS systems cannot use DOT 5, this fluid will not be used in the newer cars we ultimately restore that have this ABS feature. It is mainly for us old dinosaurs and our 40-50 year old classic cars......some older race cars........and other various miscellaneous vehicle applications. Not a major market segment.


Larry

[Patrick T.]

Re: DOT 5 - Is this new to anyone else?

When I restored my '57 Corvette basket case 20 years ago, I had to buy and install new steel brake lines. I used DOT 5 silicone brake fluid back then and have had no problems whatsoever. Just stay away from stainless steel brake lines.

[Gary R.]

Re: DOT 5 - Is this new to anyone else?

I haven't had to do my brakes in a long time but I always used DOT3, am I the last one left using it?

[Edward J.]

Re: DOT 5 - Is this new to anyone else?

I haven't had to do my brakes in a long time but I always used DOT3, am I the last one left using it?

Gary, Simple answer - no, DOT 3 OR 4 has been around for years, there's really nothing wrong with it, it does require servicing every 2-3 years according to manuf. So what its 3.99 for a Quart can, Dot 5 it 20.00-30.00 ( or more) a quart. All Car makers still use Dot 3. and there's a reason for this, cost may be a small part of it, I have been in the repair business for 40+ years and have seen dot 3 left in cars for 15- 20 years with out problems, Not that everyone is the same but lets face it, it does work. Just my 2 cents

[Terry M.]

Re: DOT 5 - Is this new to anyone else?

I have been told Harley Davidson uses DOT 5 in their motor cycles. Since that is a rabbit hole I have not gone down I have no direct experience there. According to ASE papers I have read US military tank brake systems were/are also equipped with DOT 5. I have no direct experience there either, so I don't know how extensive that use is/was.

[Gary R.]

Re: DOT 5 - Is this new to anyone else?

Thanks Ed, that has been my thinking forever

[Joe L.]

Re: DOT 5 - Is this new to anyone else?

I haven't had to do my brakes in a long time but I always used DOT3, am I the last one left using it?

Gary------


DOT 3 or 4 is fine UNTIL you get some of it on your car's paint. Then, you'll wish you had used the DOT 5; I absolutely guarantee it.

Yes, I know that we're all going to be supremely careful that we don't get DOT 3/4 on our car's paint. But, it can happen. I KNOW.

[Gary R.]

Re: DOT 5 - Is this new to anyone else?

Gary------


DOT 3 or 4 is fine UNTIL you get some of it on your car's paint. Then, you'll wish you had used the DOT 5; I absolutely guarantee it.

Yes, I know that we're all going to be supremely careful that we don't get DOT 3/4 on our car's paint. But, it can happen. I KNOW.

Hey Joe,
Yes I do know about that too!

[Donald H.]

Re: DOT 5 - Is this new to anyone else?

OK, I just spoke with Tony at SSBC. I asked if using their Dot 5 was recommended in a new/clean brake system. He said unless I knew that all the rubber components/seals (calipers and master cylinder) were rated safe for Dot 5 they would not recommend using Dot 5. He recommended Dot 4 fluid (not Dot 3 or Dot 5.1).

So I guess I'll go with Dot 4 in my 67 brake system rebuild project. Now I'm wondering about my 66 with does have Dot 5. I guess I just have to watch and wonder.

Don

[Joe L.]

Re: DOT 5 - Is this new to anyone else?

OK, I just spoke with Tony at SSBC. I asked if using their Dot 5 was recommended in a new/clean brake system. He said unless I knew that all the rubber components/seals (calipers and master cylinder) were rated safe for Dot 5 they would not recommend using Dot 5. He recommended Dot 4 fluid (not Dot 3 or Dot 5.1).

So I guess I'll go with Dot 4 in my 67 brake system rebuild project. Now I'm wondering about my 66 with does have Dot 5. I guess I just have to watch and wonder.

Don

Don------

I think this is just "play-it-safe" advice from SSBC. Once again, we need AUTHORITATIVE seal information from a brake seal MANUFACTURER.

[Dick W.]

Re: DOT 5 - Is this new to anyone else?

I have been told Harley Davidson uses DOT 5 in their motor cycles. Since that is a rabbit hole I have not gone down I have no direct experience there. According to ASE papers I have read US military tank brake systems were/are also equipped with DOT 5. I have no direct experience there either, so I don't know how extensive that use is/was.

Military uses DOT 5 because it is not hydroscopic like DOT 3 or 4.

I have DOT 5 in Kermit and have since 1985 or '86. No problems. I would have expected leaking seals due to the amount of time the car sits, but so far, nothing

[Joe L.]

Re: DOT 5 - Is this new to anyone else?

All-----

I contacted Raybestos Technical Service. Raybestos is a major manufacturer of brake system parts. They advised me that their brake caliper piston seals are compatible with DOT 5 brake fluid. I fully expect that the seals supplied by other major manufacturers (e.g. Wagner, Carlson) are also compatible but I now know, for certain, that those supplied by Raybestos are compatible with DOT 5.

However, this does not mean that all seals on the market are compatible. I would not recommend any supplied as part of "no name" or "generic brand" kits. I can tell you, for certain, that I'd never use any such parts whether DOT 5 compatibility was an issue, or not.

By the way, if CSSB or any other caliper re-manufacturer states that their warranty is void if DOT 5 brake fluid is used, then, perhaps, they're using "no-name" or "generic" parts in their rebuilding process. If they were using, say, Raybestos parts I do not understand why the warranty would be void.

[Ed D.]

Re: DOT 5 - Is this new to anyone else?

With all the helpful information regarding presently manufactured seals and rubber, has anyone determined how much if any chemical changes have been made to the DOT 5 over the years. Having DOT 5 in my Corvette for almost 35 years it would be good to know if I purchase and add new DOT 5 fluid to my system, how compatible it would be.
Ed

[Joe L.]

Re: DOT 5 - Is this new to anyone else?

With all the helpful information regarding presently manufactured seals and rubber, has anyone determined how much if any chemical changes have been made to the DOT 5 over the years. Having DOT 5 in my Corvette for almost 35 years it would be good to know if I purchase and add new DOT 5 fluid to my system, how compatible it would be.
Ed

Ed------


That's probably going to be harder to get an answer on. However, you will note that the silicone brake fluid I pictured above has a label which states that it meets military specification MIL-B-46176+Am1 and Federal Motor Vehicle Safety Standard (FMVSS) 116. I checked a container of DOT 5 brake fluid in a local auto parts store (Johnson-branded fluid). It says that it meets those exact same standards and also meets standard SAE J1705 (this standard may not have existed when my DOT 5 was made more than 20 years ago).

I feel pretty confident that if you have DOT 5 fluid that is supplied in a container that says the fluid meets all 3 of the aforementioned standards, it will be just what we're looking for.

If the container does not specifically state that it meets at least the mil spec and FMVSS, I wouldn't touch it with a 10 foot pole.