Brake Fluid

Yowza Art,
The o-rings are the really a non-issue as they are easily available for not much more money but some of the other parts are harder to come by as I ended up making some of my own diaphragms. Viton sheet material is available in a variety of thicknesses for making gaskets.
The MG Club makes the point of letting people know their fluid must be changed due to the absorbtion of moisture. Judging by some of the wheel cylinders I've changed in the past it probably should have occurred in my vehicles past pm and was neglected.
Later, Bob Lovell

Robert,

no, there were not any warnings. It was DOT 5 Silicone fuid. That was back in 1980 that I made the decision to change for the same reasons you say. But it turned out to be a bad idea. So I never used it again. Once bitten, twice shy....

I now have full synthetic brake fluid that is marked for abs or racing applications, I am sick of the mess the regular fluid makes of paint, also it wrecks your cylinders if not changed on a regular basis. How many brake system O rings are there in a system anyway, surely a higher end manufacturer could afford the extra one dollar or less to promote and prolong the usage of their vehicles..........and brag about it.........

Yowza Art D, and J.A.M.,
Art , Viton o-rings are available through almost any industrial supplier. The one thing that they will tell you is it's more money. The reason for that is, at least a few years back, the places would not stock Viton which made the sale of conventional materialed o-rings a lot easier.
McMaster-Carr has a pretty good selection, aka the Big Yelow Book for industrial and manufacturers. They sell to anyone with a credit card.
J.A.M., I'm a Luddite with a lot of things but your experience pretty much proves my point.
Also I could be wrong but I do believe Saab now uses Silicone as my father-in-law's new Turbo is marked for it.
Just for our own interest.....was there any caveat/warnings about using this with the vehicle or any other or did the can state it was "universal"?
Again, if the wrong seals are present, you'll get the sponginess you mentioned. The lack of damaging effects on the paint coupled with the fast that it doesn't absorb moisture is enough reason to use the stuff.
Twenty-five years of enduring Dot 4 and it's ability to absorb moisture....Life is too short. later Bob Lovell

Yowza Art D, and J.A.M.,
Art , Viton o-rings are available through almost any industrial supplier. The one thing that they will tell you is it's more money. The reason for that is, at least a few years back, the places would not stock Viton which made the sale of conventional materialed o-rings a lot easier.
McMaster-Carr has a pretty good selection, aka the Big Yelow Book for industrial and manufacturers. They sell to anyone with a credit card.
J.A.M., I'm a Luddite with a lot of things but your experience pretty much proves my point.
Also I could be wrong but I do believe Saab now uses Silicone as my father-in-law's new Turbo is marked for it.
Just for our own interest.....was there any caveat/warnings about using this with the vehicle or any other or did the can state it was "universal"?
Again, if the wrong seals are present, you'll get the sponginess you mentioned. The lack of damaging effects on the paint coupled with the fast that it doesn't absorb moisture is enough reason to use the stuff.
Twenty-five years of enduring Dot 4 and it's ability to absorb moisture....Life is too short.

Robert,

because I used silicone fluid in a 1979 Saab 900 T that I owned from new, and I had nothing but trouble with the braking system after. The pedal felt like marshmallows even after repeated bleedings, replacing the master cylinder, booster, pads, and more bleedings and more refills, you name it.

Then more troubles, when I took it to the selling dealer, I was told they would not work on it because of the silicone fluid label that had been applied to the fluid container.

I stick to the DOT 4 now.

J.A.M.

The same issues seem to get rehashed over and over, the site needs to be updated to allow for a search option. I have used silicon fluid (Dot 5) for almost 30 years on hundreds of cars of every type with never a problem, there is no down side to silicon. I would not use dot 3, even in my El Camino. Most european cars have specified a dot 4 fluid and Girling/Castrol LMA is all I have eveer known.

Where can I find the Viton seals / o rings, I would like to get some for my babies, Art

J.A.M., It's funny the different experiences that people have with the same product as we've had silicone brake fluid in our 69 for the past 24 years with no problems what so ever! Why do you say never again?

I used silicone brake fluid in the 1980's, and never again!

Yowza All,
As much as I like silicone fluid's ability not to eat my paint there are a few things to realize about silicone fluid.
The composition of your seals and o-rings are of major importance. For the last twenty years or so I've always rebuilt my hydraulics with a Viton seal. Viton is a little more expensive but works well with silicone. I started using viton in the plant as there was never a question of compatability with the fluids that it came in contact with plus the design specs were considerably better.
If you don't know the compositon of your seals there may be a problem. Most rubber for seals is compounded, ergo a recipe of special rubber tailored to do the job the part was intended to do. If the compund of your seal has silicone in it, silicone fluid will act as a solvent on that percentage of the rubber compound. Seals are made from nitrile, buna, buna-neoprene and a host of others along with silicone.
Numerous people have reported "spongy" brakes after switching over to the fluid. This is most likely the reason why they started to feel strange. Unfortunately almost every article on using this stuff has been very clear about mentioning the change of fluid to the people rebuilding your brake system so this can be accomodated.
Some go as far as to suggest that silicone cannot be utilized, it can but you must follow through on the seals and diaphragms. We've used it on aircraft for years and their braking performance is far more critical than our use.
I work for a company that makes belts for a variety of things, (no fan belts). We compound our own rubber. This was explained to me by our in-house rubber chemist.
Good Health to You and Yours, Bob Lovell

Use only Dot 4 fluid umless you are going to fill with Dot 5 (silicon) Dot 4 is sold by most outlets under the brand name LUCAS.

Castrol LMA Dot 4 Brake Fluid at any auto parts. Advance Auto Parts has it. Old fluid can't be trusted guys, whether DOT 3 or DOT 7. Get fresh fluid. When we are talking brakes, I'd rather spend the $5. for a new container. Just my opinion.

Thanks, Guys.
I recall buying "Girling" and "Lockheed" fluid long ago that was specifically for British hydraulics, but haven't seen that in decades.

I found not only an unopened gallon, but also a quart of DOT 3.
So, I'm set!

I'm not sure ihow significant the DOT 3 designation is, but the critical label for me has always been the one that says "Recommended by Lucas Girling".

I have a very old 12 oz can of DOT 3 that says it is recommended by all manufactuers EXCEPT Citroen. It does not mention Girling, ut it was buried in the trunk of the only car that still has Girling components and was probably suitable at the time I bought it.

I also have a can of DOT 4 (Castrol LMA Brake Fluid) with the Girling label. It's probably about 20 years old. I used it for a recent clutch slave cylinder rebuild, then found out when I went toget more that the new product no longer includes the Girling wording although it still seems to be in Castrol's catalog. No one can tell me if it's suitable, and no one under 30 knows what I'm talking about.

So, what's the bottom line? I'd save the DOT 3 especially if it says it can be used in Girling products - since I don't believe it available any more.

Dave Belanger - houston

DOT3 is fine, but DOT4 has a higher boiling point and is fully compatible with 3. More important, use Castrol LMA (Low Moisure Absorbent) to reduce the collection of moisture in a car that is not used that much.