Red Rocket
Likes Bikes and Dirt
I bleed my brakes with Singer fluid. No problems.
Shimano mineral oil?
- Thread starter Arete
- Start date
toodles
Wheel size expert
I'm trying Pentosin CHF 7.1 mineral oil in my Saints now as recommended by PVD.
This stuff goes for around $20 for a 1L tin and seems a little thinner than the standard Shimano fluid. It's green in colour and smells like a cocktail ingredient. Bleed wise, the low visco seems to make it bleed air to the top with less trouble. As for feel, i'm pressed to tell a tangible difference between the shimano and the pentosin fluids although the CHF does seem to snap back a bit better. This could be due to the new bleed though.
This stuff goes for around $20 for a 1L tin and seems a little thinner than the standard Shimano fluid. It's green in colour and smells like a cocktail ingredient. Bleed wise, the low visco seems to make it bleed air to the top with less trouble. As for feel, i'm pressed to tell a tangible difference between the shimano and the pentosin fluids although the CHF does seem to snap back a bit better. This could be due to the new bleed though.
GC @ Shimano
Cannon Fodder
For the record...
DOT fluids will ruin the seals in Shimano calipers and void the 2-year warranty (3-years for XTR).
Mineral oil offers fine performance without any of the bio-hazard drawbacks of other brake fuilds.
Shimano mineral oil can be purchased through any bike shop in Australia. It's sold in little 50mL bottles (which is a bit pricey) and 1 litre shop-size (which is not).
Shimano Australia does not recommend any DOT fluid for use in any Shimano hydraulic disc brake systems.
DOT fluids will ruin the seals in Shimano calipers and void the 2-year warranty (3-years for XTR).
Mineral oil offers fine performance without any of the bio-hazard drawbacks of other brake fuilds.
Shimano mineral oil can be purchased through any bike shop in Australia. It's sold in little 50mL bottles (which is a bit pricey) and 1 litre shop-size (which is not).
cods
Likes Bikes
Brake fluid
If your bleeding Shimano stick with shimano brake fluid. ( Red in colour )
If your bleeding Magura stick with Magura Blood ( Green in colour )
And if your brakes use dot fluid, its best to go for the lastest dot number.
4 better than 3 etc.
Yes both the mineral oils are expensive.
Just use the correct one for the brake.
From my experience, I used shimano oil in a magura once! It worked for about a week then started leaking.
They needed a rebuild all seals etc lucky they covered it with leak proof warranty.
If your bleeding Shimano stick with shimano brake fluid. ( Red in colour )
If your bleeding Magura stick with Magura Blood ( Green in colour )
And if your brakes use dot fluid, its best to go for the lastest dot number.
4 better than 3 etc.
Yes both the mineral oils are expensive.
Just use the correct one for the brake.
From my experience, I used shimano oil in a magura once! It worked for about a week then started leaking.
They needed a rebuild all seals etc lucky they covered it with leak proof warranty.
Binaural
Eats Squid
But does it taste like one? Inquiring minds want to know
Pebble - at least when he digs up old theads he adds some useful technical opinion and some relevant personal experience, which is better than 95% of the equivalent posts and given it's not worth a new thread this is the kind of digging I like to see.
Personally, I see no problem with experiementing with fluids as long as the seals or lines will not actually be embrittled, corroded or dissolved by use with a fluid that is too aggressive. I've often thought that given the relatively high viscosity of shimano mineral oil that a lighter fluid would give a snappier feel and possible provide better lubrication of the working pistons.
cods
Likes Bikes
oils aint oils
Experimenting with oil is all good! And as you say as long as it is the correct spec oil. Yes you can change the charteristic and performance of the brake.
Oil companys have had chemist designing oil for different application for years and the dot oils have come a long way. There are some very sofisticated brake oils about. go into rally shop and ask about brake fluid. (none will be mineral)
Its disappointing to watch the likes of the big S and Magura deviate from this and go to mineral oils. I am sure they have done this just to increase sale of the accessory market side of there bussiness.
The only advantage I see to using mineral oils is that is nicer on the paint and skin. Nothing wrong with this however the oil is there for the braking.
Time out from the mobile is good, people should travel by air more, or get on a bike and go for a ride.
mmm : thats an idea go for a ride, seeya.
Experimenting with oil is all good! And as you say as long as it is the correct spec oil. Yes you can change the charteristic and performance of the brake.
Oil companys have had chemist designing oil for different application for years and the dot oils have come a long way. There are some very sofisticated brake oils about. go into rally shop and ask about brake fluid. (none will be mineral)
Its disappointing to watch the likes of the big S and Magura deviate from this and go to mineral oils. I am sure they have done this just to increase sale of the accessory market side of there bussiness.
The only advantage I see to using mineral oils is that is nicer on the paint and skin. Nothing wrong with this however the oil is there for the braking.
Time out from the mobile is good, people should travel by air more, or get on a bike and go for a ride.
mmm : thats an idea go for a ride, seeya.
Tomas
my mum says im cool
I know there has been significant developments in brake fluids in high-performance automobiles... can any of it be applied to bike stuff? I like the idea of using rally-brake-fluid in my avids (although they werent designed for it and all)....
Sounds like a good (but very bad) idea.
Sounds like a good (but very bad) idea.
kv1973
Likes Dirt
brake fluid
Only shimano and magura specify mineral oil for their brake system. All the others that I know use brake fluid DOT 3 or DOT 4 etc.
I have bleed Hayes and Avid brakes using the normal Mobil automotive brake fluid dot 4 that I had in the garage. That was fine.
I later moved onto the current XTR brakes which I used Honda powersteering fluid - they use a mineral based hydraulic oil. I reckon automatic transmission oil is fine too but have not tried it. These are all forms of hydraulic oil. The XTR perform perfectly.
Only shimano and magura specify mineral oil for their brake system. All the others that I know use brake fluid DOT 3 or DOT 4 etc.
I have bleed Hayes and Avid brakes using the normal Mobil automotive brake fluid dot 4 that I had in the garage. That was fine.
I later moved onto the current XTR brakes which I used Honda powersteering fluid - they use a mineral based hydraulic oil. I reckon automatic transmission oil is fine too but have not tried it. These are all forms of hydraulic oil. The XTR perform perfectly.
Mineral Oil vs Hydraulic oil for brakes. The main advantage / disadvantage is this: (in my opinion)
Mineral oil does not absorb water. Hydraulic oil is hydroscopic (absorbs water)
What does this mean?
Every brake oil is rated with a dry and wet boiling point. The dry boiling point is just that dry. no water. The wet is (I can't remember off the top of my head) around 0.5% concenration or something like that.
Mineral oils.. do no suffer anywhere NEAR as much when water is mixed (if at all)
However, hydraulic oils suffer greatly. How?
1) the water starts to rust your lines, calipers etc... THis is why your car should have a full bleed every 12 months.
2) the wet boiling point is dramaticly less then the dry.. i.e your braking effeciently will be GREATLY reduced. I can't remember the fluid.. (might be motul or something) but one I recently came across the different was 60% drop in boiling point when wet.
now.. to the people talking about 'I want rally brake fluid' there are some points worth noting
(a) the fuild used by many of the top ARC teams (and us) is Castrol SRF. This is $160 per litre. They don't come in smaller bottles... that I've seen anyhow.. and once opened... throw the rest away... as it is absorbing water...
(b) They have a very high dry boiling point.. but suffer greatly when wet. (SRF is the best of the bunch in this field)
(c) we bleed / replace after each event because no matter how good, how sealed, how you look after the braking system.. water gets in.. air has moisture.. it just gets in...
(d) SRF will only cope in systems where the materials are suitable. I.e your brake system's material may not be compatable and the SRF fluid will destory your system...
Finally.. the last point.. every hydraulic oil has different compressability features. I.e One oil in your system will make the brakes fell less/more progressive then the next... but this is in a car world.. how it would change things on a bike system? no idea.
just some points to ponder
edit : I found the website that I think is EXCELLENT when talking about brake fluids..
http://www.stoptech.com/tech_info/wp_brakefluid_1a.shtml
Mineral oil does not absorb water. Hydraulic oil is hydroscopic (absorbs water)
What does this mean?
Every brake oil is rated with a dry and wet boiling point. The dry boiling point is just that dry. no water. The wet is (I can't remember off the top of my head) around 0.5% concenration or something like that.
Mineral oils.. do no suffer anywhere NEAR as much when water is mixed (if at all)
However, hydraulic oils suffer greatly. How?
1) the water starts to rust your lines, calipers etc... THis is why your car should have a full bleed every 12 months.
2) the wet boiling point is dramaticly less then the dry.. i.e your braking effeciently will be GREATLY reduced. I can't remember the fluid.. (might be motul or something) but one I recently came across the different was 60% drop in boiling point when wet.
now.. to the people talking about 'I want rally brake fluid' there are some points worth noting
(a) the fuild used by many of the top ARC teams (and us) is Castrol SRF. This is $160 per litre. They don't come in smaller bottles... that I've seen anyhow.. and once opened... throw the rest away... as it is absorbing water...
(b) They have a very high dry boiling point.. but suffer greatly when wet. (SRF is the best of the bunch in this field)
(c) we bleed / replace after each event because no matter how good, how sealed, how you look after the braking system.. water gets in.. air has moisture.. it just gets in...
(d) SRF will only cope in systems where the materials are suitable. I.e your brake system's material may not be compatable and the SRF fluid will destory your system...
Finally.. the last point.. every hydraulic oil has different compressability features. I.e One oil in your system will make the brakes fell less/more progressive then the next... but this is in a car world.. how it would change things on a bike system? no idea.
just some points to ponder
edit : I found the website that I think is EXCELLENT when talking about brake fluids..
http://www.stoptech.com/tech_info/wp_brakefluid_1a.shtml
Last edited:
cods
Likes Bikes
Can you afford it?
The rally guys don't just use because they can, they use it because it works better, cost is no barrier at this end of the race scene.
So I ask, can afford not to use it? I say give it a go in you Avids these are compatable spec fluid, souldn't be a problem to the equipment.
If you prepared to, let us know your personal experiance.
I have a new bottle of AP Locheed 550 Racing Brake fluid 500ml just havn't used it as I Know I have to chuck the rest away. So keep waiting to bleed a couple of sets ( just hasn't lined up )
I am not sure how long it will last before you will need to bleed again. Guess that will be depending on the enviromental conditions.
I am sure it will improve the performance of the brakes.
Thomas posted web is worth the read.
The rally guys don't just use because they can, they use it because it works better, cost is no barrier at this end of the race scene.
So I ask, can afford not to use it? I say give it a go in you Avids these are compatable spec fluid, souldn't be a problem to the equipment.
If you prepared to, let us know your personal experiance.
I have a new bottle of AP Locheed 550 Racing Brake fluid 500ml just havn't used it as I Know I have to chuck the rest away. So keep waiting to bleed a couple of sets ( just hasn't lined up )
I am not sure how long it will last before you will need to bleed again. Guess that will be depending on the enviromental conditions.
I am sure it will improve the performance of the brakes.
Thomas posted web is worth the read.
udi
swiss cheese
Wow, justinb has just dropped a whole pile of misinformation.
a) DOT3/4/5/1 fluids are not oils, they are polyglycol-ether fluids.
b) The above DOT fluids are hygroscopic, not hydroscopic. Refer to a dictionary.
c) The above fluids do not rust lines and calipers. For starters, all mtb brakelines have a teflon inner, teflon obviously doesn't rust. But more specifically, the glycol-ether fluids actually absorb water, which will disallow water from remaining localised in any area of the brake. Therefore, no rust.
I could keep going, but in short (to everyone else) don't believe everything you read. Also keep in mind that motorsport based data will not necessarily apply to mtb.
I've spent a fair amount of time on both mineral oil and glycol fluid brakes, and in mtb, getting them setup right isn't rocket science. Boiling points aren't critical (any good fluid will have a high enough BP), low viscosity is... I spent the time looking up the viscosity figures on a variety of fluids and the lightest fluids I found were as follows.
Avid/Hayes/Hope (DOT3/4/5.1 family):
Motul DOT 5.1 brake fluid
Shimano/Magura (Mineral oil family):
Redline LikeWater suspension fluid
The likewater is actually a synthetic oil rather than a mineral oil, but works great in the shimano brakes. I ran a full season on the fluid, and j5ive on here ran the stuff in his saints too. If you can't get that stuff, just stick with genuine shimano mineral oil - ATF is too thick, and forget everything else.
Hope that sets a few things straight... seriously this thread didn't need to be dug up. Cods, please refrain from replying to old threads just for the sake of increasing your post count to gain trading access.
a) DOT3/4/5/1 fluids are not oils, they are polyglycol-ether fluids.
b) The above DOT fluids are hygroscopic, not hydroscopic. Refer to a dictionary.
c) The above fluids do not rust lines and calipers. For starters, all mtb brakelines have a teflon inner, teflon obviously doesn't rust. But more specifically, the glycol-ether fluids actually absorb water, which will disallow water from remaining localised in any area of the brake. Therefore, no rust.
I could keep going, but in short (to everyone else) don't believe everything you read. Also keep in mind that motorsport based data will not necessarily apply to mtb.
I've spent a fair amount of time on both mineral oil and glycol fluid brakes, and in mtb, getting them setup right isn't rocket science. Boiling points aren't critical (any good fluid will have a high enough BP), low viscosity is... I spent the time looking up the viscosity figures on a variety of fluids and the lightest fluids I found were as follows.
Avid/Hayes/Hope (DOT3/4/5.1 family):
Motul DOT 5.1 brake fluid
Shimano/Magura (Mineral oil family):
Redline LikeWater suspension fluid
The likewater is actually a synthetic oil rather than a mineral oil, but works great in the shimano brakes. I ran a full season on the fluid, and j5ive on here ran the stuff in his saints too. If you can't get that stuff, just stick with genuine shimano mineral oil - ATF is too thick, and forget everything else.
Hope that sets a few things straight... seriously this thread didn't need to be dug up. Cods, please refrain from replying to old threads just for the sake of increasing your post count to gain trading access.
