I’ve got Shimano brakes on one bike and Magura on another.

Do I need different Brake fluid for each? Is the Shimano Mineral oil (red) and the Magura Royal Blood (blue) essentially the same stuff just different colours?

Don’t plan on mixing the two together (Hmm.. Purple fluid), just want to know if I need to buy separately for each system.

I have heard that if Magura find non-Magura fluid in their brakes they won’t warranty them.

Make of that what you will.

you need seperate stuff. Shimano stuff will probably destroy the magura seals.

They both use mineral oil, and I’ve seen quite a lot of people mixing shimano levers with magura calipers (it’s called shigura!) and using shimano mineral oil (because it’s cheaper). No issues reported.

Although BillOddie may be right about warranty, you may want to check this before.

The manufacturers say they aren’t compatible, these guys say they (probably) are:

https://www.epicbleedsolutions.com/blog/dot-brake-fluid-vs-mineral-oil/

This is interesting too:
https://bikerumor.com/2013/04/11/tech-speak-brake-fluid-break-down-and-implications-for-road-disc-updated/

Also, if it were my brakes, I’d use the correct fluid just so I didn’t have to worry about it. In an emergency, I’d use any mineral fluid in any brake designed for mineral oil.

I’ve been using Citreon hydraulic mineral oil in both Maguras (Hs33s of course cos I’m old school) and Shimano brakes for years. No issues at all.

It’s mineral oil for a hydraulic system, whatever the manufacturer says, it will be fine.
Of course they want you to buy their stuff. It’s got a nice hefty profit margin built in.

See also…bike specific DOT fluid, bike specific grease, and special MTB brand specific fork oil.

Just like your car, innit? As long as it’s called “engine oil” it’s all the same.

Don’t be daft, you know that’s not what I meant 😉
However, Citroen hydraulic oil has been used by many people got many years with no issues.

Mineral oil of a decent spec will have zero adverse effect on brakes using mineral oil such as these.

Just like your car, innit? As long as it’s called “engine oil” it’s all the same.

If your car manufacturer says a certain brand of oil but you use another manufacturers to the same spec?

it’s the same

Mineral oil of a decent spec will have zero adverse effect on brakes using mineral oil such as these.

Define “decent spec”

Mineral oil is just a generic term for a crude oil refining by-product and will cover a huge range of oils with various properties.

He probably meant oil that has been specifically developed for use in hydraulic systems, i.e. brakes, power steering, leveling, etc.
But you probably knew that 😘

No experience of Magura oil but Shimano is significantly less viscous than Citreon stuff, which makes getting a good bleed with Shimano stuff significantly easier.

In the grand scheme of things by the right oil for your brakes is pennies.

That being said…it would be interesting to get some spare seals for Magura and Shimano brakes and soak them in all 3 types of “Mineral Oil” and seeing if there is any degradation or swelling over time.

There wouldn’t be. It’s not like Shimano or Magura use a special, top-secret, unobtanium rubber for their seals.

If your car manufacturer says a certain brand of oil but you use another manufacturers to the same spec?

Where can I find the spec of Shimano mineral oil so that I can check against other brands?

Well, both sets are out of warranty, so thats not an issue. Maybe just be sensible and stick the reccomended stuff in there. Both sets have been very happy brakes, and it’s not like I’m going to get through loads of fluid.

I have to say though, the Maguras have been excellent brakes, maybe not quite as good as the Shimano performance wise, but never needed bleeding, except after maintenance, no leaks, decent pad wear etc..

Much prefer my MT5’s to the Shimano brakes I have had in the past. I’ve just bled them with Shimano mineral oil as that’s what Epic Bleed sent me when I bought the bleed kit.

https://bike.shimano.com/en-US/information/news/mineral-oil-brake-fluids.html

https://www.georgesbikeshop.com.au/wp-content/uploads/2017/01/Shimano-Hydraulic-Mineral-Oil_Eng.pdf

So, from that safety sheet do we infer that Shimano Hydraulic oil is Shell Tellus C8 or C10? I assume the number is a viscosity reference…