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405 Posts
Discussion Starter #1
What mineral oil can be used for the Magura clutch on my 950 SMR, other than the Motorex clutch fluid 75 recommended in the owners manual?

And is there a special technique needed to bleed it?


Premium Member
31,407 Posts
Buy two syringes of ebay or a vets and 1m of small bore clear plastic tube from B&Q. Some people sell the complete bleeding kit on ebay.

Attach about 150mm of tube to each of the syringes.
Fill one syringe with ATF (any AutomaticTransmissionFluid from any garage or car parts shop)
Take the top of the master cylinder and suck it dry with the other syringe.
Undo the slave cylinder nipple and take it off and clean it out incase mud is in there.
Replace the nipple but leave it 1 full turn out and attach the full syringe.
Push the syringe to force ATF through the system. Around 40ml will do it easy. Keep the level of the master cylinder down by sucking out as required, or just let it overflow :)
Dont worry if it leaks from the threads of the nipple on the slave.
When it is done, tighten the nipple, detact the clean syringe and then set the level in the master cylinder to 4mm below top.
Clean up the rubber bellows thing inside the top, make sure it is not kinked and refit it.

3,801 Posts
LHM works OK and is easily available its the stuff Citroen use in their suspension

405 Posts
Discussion Starter #7
As I needed to get the bike usable for Monday (except it snowed!), and I could not get to a Halfords in time, I bought some baby oil from Boots.

Used a large syringe as suggested and refilled from the slave cylinder nipple and just allowed it to overflow from the master cylinder (only had the one syringe).

Worked a treat and clutch is now functioning again (I lost all use of it because of the leak). Just keeping an eye on the level and will top up as required. Have to do this as slave cylinder is being replaced FOC, but the earliest that I can get it booked in is in the New Year.

Thanks for all the help.

3,303 Posts
Glad I searched for this... just flushed the gearbox out switched to 10/40 oil, so was wondering what I was going to do with the other 3L of ATF I've got in the garage... that's a lot of clutch oil changes!

What sort of life expectancy does the ATF have in the clutch hydraulics?

408 Posts
Me being me I'm probably over thinking this! lol

- Motorex Hydraulic Fluid 75 100ml @ £8

Only specs to be found on this stuff:
ISO VG (15)
Excellent age resistance.Ideal viscosity at both high and low temperatures.
High seal compatibility.
Area of application: Whenever the manufacturer recommends a mineral oil based fluid.

- Putoline Hydraulic Clutch Fluid 125ml @ £4.48

...is a mineral clutch fluid. It protects against wear and oxidation. Hydraulic Clutch Fluid is suitable for Magura and other makes.

Putoline Oil is a high-quality supplier of a wide range of lubricants and maintenance products. We only supply products for motorised two-wheelers and that makes us unique! Our years of experience, combined with continuous research results in the best price/quality ratio. Manufacturing our own products guarantees a consistently high quality.

Product specifications:
DIN 51524-2 HLP
Typical standard analyses
Density at 15 °C, kg/l 0,888
Viscosity 40 °C, mm²/s 10,00
Viscosity 100 °C, mm²/s 2,60
Viscosity Index 90
Flash Point COC, °C 172
Pour Point, °C -30
Acid number, mgKOH/g 0,30
Sulphate Ash, % 0,06

- ATF: various specs available, typical cost £9 for 1ltr (1000ml!!)
Example: Castrol Transmax Dex III Multivehicle Car Automatic Gearbox Oil (ATF)

Multiple manufacturer approvals make Castrol Transmax Dex III Multivehicle ATF suitable for wide ranging use.
Transmax Dex III Multivehicle is specifically formulated for high thermal stability and resistance to oxidation which protects against the formation of deposits and oil thickening prolonging the life of components and lubricant.
Optimised friction characteristics provide smooth shifting and efficient power transfer.
High viscosity index provides a stable viscosity over a wide temperature range for effective protection of transmissions and operation of power steering units

Density @ 15C, Relative (ASTM D4052) : 0.859 g/ml
Colour (ASTM D1500) : Red
Viscosity, Kinematic 100C (ASTM D445) : 7.2 mm²/s
Pour Point (ASTM D97) : -46°C
Viscosity, Brookfield @ -40C (ASTM D2983) : 16500 mPa.s (cP)
Viscosity, Kinematic 40C (ASTM D445) : 35mm²/s
Viscosity Index (ASTM D2270) : 175
Flash Point, COC ASTM D92 °C 216

- LHM: various specs available, typical cost £9 for 1ltr (1000ml!!)

Example: Castrol LHM+ Citroen Mineral hydraulic fluid

Mineral based hydraulic fluid
For use in powered hydraulic systems, such as brake actuation, suspension leveling and power steering
High viscosity index (VI)
Very sheer stable
Thermally stable
Working temperatures ranging -40°C to 100°C
Compatibility to all elastomeric components
Castrol LHM+ has excellent lubricity performance ensuring reduced wear and longer component life and contains excellent corrosion inhibitors and antioxidants, providing protection to all metals components.

Flash Point NFT 60-103 °C 110
Density @ 20C IP 160 g/ml 0.844
Viscosity, Kinematic -40C IP 71 mm²/s 1150
Viscosity, Kinematic 40C IP 71 mm²/s 20
Viscosity, Kinematic 100C IP 71 mm²/s 6.2
Viscosity Index IP 226 None 320
Pour Point ISO 3016 °C -50
Appearance Visual - Fluorescent green clear mobile liquid

At the end of the day cost initially isn't really an issue when you're talking a tenner what ever way you go (however what impact might there be on time to clutch master and slave cylinder rebuilds??).........the ATF or LHM makes more sense from the point of view of having plenty of excess fluid to give the system a good flush through.
I know ATF and LHM work fine as a number of guys have said they've been using it but the specs between ATF and LHM vary a lot and even more so from the Putoline Hydraulic Clutch Fluid which, as Putoline states, is suitable for Magura and other clutch systems (and therefore I assume a close match with the Motorex fluid).
e.g. Viscosity Indexes:
ATF 175
LHM 320
PUT 90
Viscosity 40°C, mm²/s:
ATF 35
LHM 20
PUT 10
Viscosity 40°C, mm²/s:
ATF 7.2
LHM 6.2
PUT 2.6

Yeah I know.....anal geek! :eek:

Decisions decisions :confused: ............any thoughts comments?....


408 Posts
....and from ADVRider forum:,
".....with regard to the problems some owners have faced with the slave cylinders failing early, one seemingly knowledgeable member wrote:

the problem is sintered aluminum + mineral oil + heat + pressure. Its called a solvothermic reaction. Swap to a synthetic fluid that's non reactive with the sintered aluminum cylinder and there is absolutely no issue with the stock unit. 60+k miles and no failures. Same for every one of my customers and friends who I've swapped over to 3w synthetic fork oil.. I could make 35% selling these replacement slave but it really isn't necessary, IMHO.

Anyone confirm or deny?

1,263 Posts
I used Shimano brake fluid in my SM990 when I first got it and worked much better. Checked on it a couple of years later and no discolouration.
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