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Shimano Mineral Oil?

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#41 ·
What you want is aircraft hydraulic fluid, it's mineral oil based and as far as I can tell it's very similar or the same as the stuff that Shimano uses. I've been using it in my Shimano brakes for several years and so far it works just fine. You can order it from here and they'll ship it right to your door.
 
#44 ·
I've never used a DOT fluid system in the winter so I have nothing to compare it to, but I can't say I've ever had any issues using my brakes in the winter. I've gone down to a bit under -15°C and everything was still working fine, the lever feel was a bit different but it's hard to say whether it's the brakes, my winter gloves, or my frozen fingers that were responsible, probably all the above.
 
#45 ·
Hmm, well i've only used mineral oil hydro once on a winter ride(borrowed bicycle)... maybe it was a bad bleed since i've not ridden them in the cold since, but the brakes lost almost all stopping power after a few hr.
 
#46 ·
That is strange, I also wonder what would cause that issue.

The only big difference I notice in the cold is my fork stiffening up and slowing down after a while. I figure if the fork's getting frozen then the brakes are about as cold as they'll get. The only big difference with my brakes is the honking noise it makes as the snow & ice gets melted and wiped off the rotor & caliper when I start braking.
 
#47 ·
Ah, maybe something resolved on the newer designs - they might use different spec mineral fluid? Trying to decide if i should go juicy 3 or slx for the winter road beater, already have a juicy bleed kit, but rumors are juicy 3 isn't that durable.
 
#48 ·
Forgot to mention that the disc brake I have is the old 4-piston XT (M755) from 11 years ago. Also rode my friend's bike with newer XT's (I think they're the M765) for a bit and it also works fine in the cold. As for juicy 3 or SLX, heck if I know, I've seen them but I've never used them.
 
#49 ·
aerius said:
Forgot to mention that the disc brake I have is the old 4-piston XT (M755) from 11 years ago.
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I'm still using mine as well, they just keep working even after all these years. I thought I might have trouble finding pads at one point when mec stopped carrying the coolstop red ones, but I've found them at other shops. I even found two sets that came with spare expansion spring clips, useful since I doubt I could ever source them from shimano.

Oh and mine have worked fine in the winter as well, no problems at -15.
 
#50 ·
I get it, you read on some other forum, or some "pro" biker, or someone in a pro shop told you to never use any other oils and you think it's gospel, but it's bad science.

The best, cheapest hydro brake fluid for "mineral oil" brakes, is Johnson's ORIGINAL baby oil. Baby oil = Pure, LIGHT mineral oil, plus a little scent. If it's not going to dry rot or destroy a baby (where lawsuits are endless) it's gentle enough for the internals of a hydro disc brake system on a bike. The key is, it has to be a mineral oil brake system. My tektros that came on my first Specialized just said mineral oil, that's when I used my job to do a little research.

Also, I stressed ORIGINAL because they have some with aloe, and vitamins in it. Now that might gum up the works.

Original Johnson's baby oil is 99.9%

"Low Viscosity Solution of Light Mineral Oil"

Here is the MSDS for Johnson's

rsu19.org/assets/files/safety/msds/Johnson%20Baby%20Oil.pdf

Go, put some in the fridge, put some on a frying pan, put it on a rubber gasket for weeks on end, check it out for yourself.
 
#51 ·
engineer said:
The best, cheapest hydro brake fluid for "mineral oil" brakes, is Johnson's ORIGINAL baby oil. Baby oil = Pure, LIGHT mineral oil, plus a little scent. If it's not going to dry rot or destroy a baby (where lawsuits are endless) it's gentle enough for the internals of a hydro disc brake system on a bike. The key is, it has to be a mineral oil brake system. My tektros that came on my first Specialized just said mineral oil, that's when I used my job to do a little research.
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Baby oil is emergency use only, long term use is bad for your brake system.

The mineral oil designed for use in hydraulic systems, and this includes brakes, contains corrosion inhibitors, anti-wear agents, viscosity modifiers & stabilizers and various other things to keep the system working at its best. Without all those things in there, the brakes will corrode and wear faster and give inconsistent performance depending on temperature. That's why baby oil is emergency use only.
 
#52 ·
aerius said:
Baby oil is emergency use only, long term use is bad for your brake system.

The mineral oil designed for use in hydraulic systems, and this includes brakes, contains corrosion inhibitors, anti-wear agents, viscosity modifiers & stabilizers and various other things to keep the system working at its best. Without all those things in there, the brakes will corrode and wear faster and give inconsistent performance depending on temperature. That's why baby oil is emergency use only.
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Maybe in the text books you get corrosion but in my 7 year old xt's it working fine.
Just an observation.....or a long emergency
 
#53 ·
On the other hand, I saw enough sets of damaged brakes in my bike shop days* from people using non-approved fluids including baby oil. Just because you got away with it doesn't mean it's a good idea for everyone else.


*I worked in the earlier days of disc brakes when people would put all kinds of fluids in their brake systems; vegetable oil, baby oil, chain lube, suspension fork oil, ATF & power steering fluid, water, alcohol, and probably a few others I've forgotten.
 
#54 ·
Baby oil is itself a corrosion inhibitor. And if you're worried about viscosity breakdown, just change the fluid more regularly. At the cheap price of baby oil, you can change it weekly if you want. If you want to spend more money and go out of your way to run the BEST hydro fluid in your brakes, there is nothing wrong or bad or evil about the expensive stuff. But if you live far away, don't want to pay for shipping, or just on a budget, and your brakes call for mineral oil, original baby oil will do just fine, year in and year out. As for other fluids, like veg. oil, DOT fluid, etc... it's not the same stuff, and that WILL ruin your brakes.
 
#55 ·
It's a corrosion inhibitor to a certain extent but it's not going to provide high temperature oxidation protection. And it's not just viscosity breakdown that's a problem, without viscosity modifiers its viscosity will change drastically over a given temperature range, in other words, performance & feel when cold will be different from when it's hot. Proper hydraulic fluid greatly reduces these differences.

As for cost, the good aviation grade stuff is $7 a quart plus a whopping $8.20 to ship it to your door. That's enough fluid to keep a fleet of bikes running for 10 years. If you can't afford $15 over 10 years, you have much more important things to worry about than griping over mineral oil brake fluids.
 
#56 ·
aerius said:
I've never used a DOT fluid system in the winter so I have nothing to compare it to, but I can't say I've ever had any issues using my brakes in the winter. I've gone down to a bit under -15°C and everything was still working fine, the lever feel was a bit different but it's hard to say whether it's the brakes, my winter gloves, or my frozen fingers that were responsible, probably all the above.
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dot will be fine, cars all drive in the winter, its whats in them.

frankly hydraulic brakes should all use DOT, its standard and easy, nice. kinda like schreader valves.
 
#57 ·
aerius said:
It's a corrosion inhibitor to a certain extent but it's not going to provide high temperature oxidation protection. And it's not just viscosity breakdown that's a problem, without viscosity modifiers its viscosity will change drastically over a given temperature range, in other words, performance & feel when cold will be different from when it's hot. Proper hydraulic fluid greatly reduces these differences.

As for cost, the good aviation grade stuff is aircraftspruce.ca/catalog/lgpages/phillips66XC5606H.php]$7 a quart plus a whopping $8.20 to ship it to your door. That's enough fluid to keep a fleet of bikes running for 10 years. If you can't afford $15 over 10 years, you have much more important things to worry about than griping over mineral oil brake fluids.
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Your point is well taken about the cost of the off brand aviation grade stuff. But I was more on about stuff like this...

amazon.com/Tektro-Hydraulic-Mineral-Brake-Fluid/dp/B001GSKLU4

which is literally 2300% more expensive than baby oil.

And I'm not arguing that there isn't better stuff than baby oil, of course there is better, more purpose built stuff.

The only thing I'd argue with you on is that baby oil isn't going to protect against corrosion at high temps. We almost always use baby oil in our machine shop as a cutting oil because of it's ability to evenly spread out heat, and prevent corrosion at high temps, and maintain it's integrity at high temps preventing the tools from welding to the material being cut.

That's why I even started using Baby Oil in the first place. We have it in bulk in our machine shop, so it's just too easy to load my bike up on it. Is it the best? Not by a long shot. Will it destroy my brakes? Not by a long shot.
 
#58 ·
There's a big difference between use in a machine shop where there's generally a large supply of oil being circulated onto the tool and changed at frequent intervals compared to a brake system where there's a comparatively small amount fluid which stays in the system for extended periods of time.

In machine shop operations the oil is never exposed to high temperatures for an extended amount of time, thus oxidation is not a problem. With brakes, the oil gets baked for up to tens of minutes at a time depending on what's being ridden, then it sits there and gets baked again with each ride. The oil itself gets oxidized, you'll probably have acid formation to go with it and that's when things get ugly. Proper brake fluids have anti-oxidation agents to prevent this from happening.

Now if you never use your brakes hard enough to get them toasty or you flush them with fresh fluid after every few hot runs, you could get away with using baby oil for a very long time. I still wouldn't recommend it except for emergencies considering that you can get actual aircraft brake fluid for a very good price. It has all the good stuff in it and it's actually designed for use in brakes & hydraulic systems. It's very likely the same stuff that Shimano & friends sells after slapping a giant markup on it.
 
#59 ·
veteran_youth said:
I have a big jug of Shimano oil here (Cycle Solutions Kingston Rd).

The small containers are incredibly overpriced, if you bring something small to carry it out in I will pour you a few bleeds worth for like $5.

Andrew

Cycle Solutions: Home Page
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I know your post was 3 years old but is there a chance you have some of that oil in stock? I'll drop by as soon as possible.
 
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#60 ·
engineer said:
Your point is well taken about the cost of the off brand aviation grade stuff. But I was more on about stuff like this...

amazon.com/Tektro-Hydraulic-Mineral-Brake-Fluid/dp/B001GSKLU4

which is literally 2300% more expensive than baby oil.

And I'm not arguing that there isn't better stuff than baby oil, of course there is better, more purpose built stuff.

The only thing I'd argue with you on is that baby oil isn't going to protect against corrosion at high temps. We almost always use baby oil in our machine shop as a cutting oil because of it's ability to evenly spread out heat, and prevent corrosion at high temps, and maintain it's integrity at high temps preventing the tools from welding to the material being cut.

That's why I even started using Baby Oil in the first place. We have it in bulk in our machine shop, so it's just too easy to load my bike up on it. Is it the best? Not by a long shot. Will it destroy my brakes? Not by a long shot.
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I have to second engineer's post. Been using it also, no problems and my brakes are never happier. But to each his own opinions.
Ride safe bro!
 
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