rogerbrener

Question, Is it okay to use the Clear Mineral Oil you get at your local drug store like CVS that's used sometimes for a Laxative instead of the more expensive Red Tinted Finish Line Mineral Oil. I don't see any difference except for the tint. Tektro Brakes. on a Specialized Carbon Sirrus. Thank You for the Help. Roger, Vista, Ca

Cyclist0108

No.

Is it ok to drink methanol rather than ethanol? I don't see any difference with that, either.



The viscosity of the Shimano stuff is different. The MSDS (PDF download from Shimano) lists other components.

Iride01 

Are you sure. I thought glycerol was plant and animal sources. Mineral oil as suggested by the name "mineral" should be a petroleum product.

However I wouldn't use it in my brakes just from asking here. I'd find out what the manufacturer of my brakes recommends. Why chance water absorption issues or something gumming up or swelling or disintegrating seals, hoses and other parts just because it was handy?

Cyclist0108

No. You are right. I now think that what I wrote (and now have deleted) is wrong:

https://en.wikipedia.org/wiki/Mineral_oil

(I assumed the stuff people use as a laxative was glycerol, but apparently not, and the idea of putting petroleum distillates in a GI tract seems kind of sketchy, especially if it is potentially a class 1 carcinogen.)

rogerbrener

Thank You for the Help. I looked up the MSDS for CVS Mineral oil and it states it's 100% Mineral oil, Petroleum Based. Didn't say Glycerol anywhere. I just thought someone had already been using it with success already. Feels Like High School Chem Class. Roger

HillRider

The only possible difference between CVS's mineral oil and the bike-specific mineral oil sold for use in disc brakes may be the boiling range since mineral oil is a mix of hydrocarbons, not a single chemical compound. You need to have the correct boiling range since too low will not tolerate the heat brakes develop.

Iride01 

Just because someone else may have used it, do you want to chance messing up what on many bikes is a pretty pricey item?

Admittedly, I haven't even read what Shimano recommends for my ultegra hydraulic brakes. But pure food or pharmaceutical grade seems like it wouldn't have the additives to help protect the brake lines and components from various things that are bad for a hydraulic system.

Cyclist0108

I was wrong about that, (and I teach chemistry, although not at high school, but sometimes it feels that way.)

Iride01 

Well I went back and read the DM on my r8050 STI's. It only recommends Shimano Mineral Oil. Since now it's easier for companies to claim their blends as a trade secret in the MSDS's now, it's a little harder to say if it's different. However there are some chemical names used in the description of it's formula that aren't used for other places I was able to find a MSDS on food grade mineral oils. The food grade mineral oils simply listed "mineral oil" in the COMPOSITION/INFORMATION ON INGREDIENTS.

Perhaps the other things listed in Shimano's MSDS is just the red dye, but still, I'm currently of the opinion I'll only use their recommended product. Mainly because mine is still in warranty and even when out of warranty, I don't want to have to replace upwards of $400 worth of parts, shifters and disc brake calipers, just to save the extra cost of shimano's brake fluid.

squirtdad

Why in the world would anyone try to save a few cents and risk a) malfunction of brakes b) invalidating warranty c) possible permanent damage to your disk brakes?

The ROI is not there and the ROD (risk of doing) is

I see these threads all the time i Mechanics and just don't get it.

ok that said of of my lawn whipper snappers