Left Handed Rear Brake, (Help Wanted)

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you know we have all the answers here!

why would you go elsewhere? :shock:

synthetic 5.1 is the stuff. there are many, many threads here mentioning the 5.1.

I'm about to change from a 9.5mm M/C to the 10.5mm. although at a standstill I have a full lever it doesn't amount to a bag of beans riding due to the length of the brake pipe.

any contact with DOT BF will result in the seals dying either minutes later or slowly over Months.

regards

Taffy

Taffy said:

any contact with DOT BF will result in the seals dying either minutes later or slowly over Months.

regards

Taffy

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That's an odd statement. If memory serves me, it was you who turned me on to the mineral oil MC conversion to brake fluid for the LHRB in the first place some time ago!?

Chas said:

Taffy said:

any contact with DOT BF will result in the seals dying either minutes later or slowly over Months.

regards

Taffy

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That's an odd statement. If memory serves me, it was you who turned me on to the mineral oil MC conversion to brake fluid for the LHRB in the first place some time ago!?

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yes thats right. SYNTHETIC 5.1 BRAKE FLUID AND NOT THE OLD DOT stuff. HAVING SAID THAT i GUESS the 5.1 is a DOT code so maybe i need to say DOT non-synthetic thingy stuff. :twisted: :twisted:

I never let facts get in the way of a bloody good story!

regards

Taffy

So in order to use my existing Magura clutch as a rear brake, can I just flush the mineral oil out my clutch and use 5.1 or can I flush out the rear brake and use the biodegradable hydraulic oil SAE 10?

Would I need to change the seals? :?

Thanks in advance,

Jeff

HusaWhat said:

So in order to use my existing Magura clutch as a rear brake, can I just flush the mineral oil out my clutch and use 5.1 or can I flush out the rear brake and use the biodegradable hydraulic oil SAE 10?

Would I need to change the seals? :?

Thanks in advance,

Jeff

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Don't go by the rating, go by the actual fluid chemical. I.E., use silicone brake fluid. DOT 5.1 does not guarantee that the fluid is silicone, just that the fluid meets certain standards - so to be safe make sure it is silicone.

Also, don't sue me if it ruins your seals in the Magura clutch MC - I haven't tried it. I don't think it will from what I have read, but I don't know for sure.

DOT (Department of Transportation)
DOT 3, 4, 5.1 are a glycol base will not work for long with mineral oil hydraulic rubber parts be careful
DOT 5 is a silicone base, this will work with mineral oil rubber parts or glycol base brake fluid rubber parts
I used BEl RAY Silicone brake fluid in my 2010 Husaberg with a Magura 9mm piston Master cylinder for the LHRB
The 9mm piston gives very good hydraulic pressure with great braking force. This Magura master cylinder was made for mineral oil and the caliber for glycol, the Silicone fluid works with both rubber types.
Silicone brake fluid is difficult to get the air bleed from it. Silicone holds onto air like glycol absorbs moisture. Don't shake or pump silicone fluid when installing, gravity bleed or very low pressure bleed.
The brake lever will be a little spongy (soft) with a 9mm piston and silicone, microscopic air bubbles cause this, compared to a 9.5 piston size and glycol fluid. I use the most aggresive EBC brake pads, the MX series.
Not a fan of the foot brake, to confusing. Once you are programmed for the LHRB the foot brake seems as antiquitied as a kick starter :bounce3:
My 2009 yz 250 has a LHRB AJP master cylinder 9.5mm piston the rubber parts are designed for glycol based brake fluid, works great
The Husaberg needed the 9mm piston for higher braking pressure for the difference in weight.
have a great ride
Haskell in Idaho

Haskell said:

DOT (Department of Transportation)
DOT 3, 4, 5.1 are a glycol base will not work for long with mineral oil hydraulic rubber parts be careful
DOT 5 is a silicone base, this will work with mineral oil rubber parts or glycol base brake fluid rubber parts
I used BEl RAY Silicone brake fluid in my 2010 Husaberg with a Magura 9mm piston Master cylinder for the LHRB
The 9mm piston gives very good hydraulic pressure with great braking force. This Magura master cylinder was made for mineral oil and the caliber for glycol, the Silicone fluid works with both rubber types.
Silicone brake fluid is difficult to get the air bleed from it. Silicone holds onto air like glycol absorbs moisture. Don't shake or pump silicone fluid when installing, gravity bleed or very low pressure bleed.
The brake lever will be a little spongy (soft) with a 9mm piston and silicone, microscopic air bubbles cause this, compared to a 9.5 piston size and glycol fluid. I use the most aggresive EBC brake pads, the MX series.
Not a fan of the foot brake, to confusing. Once you are programmed for the LHRB the foot brake seems as antiquitied as a kick starter :bounce3:
My 2009 yz 250 has a LHRB AJP master cylinder 9.5mm piston the rubber parts are designed for glycol based brake fluid, works great
The Husaberg needed the 9mm piston for higher braking pressure for the difference in weight.
have a great ride
Haskell in Idaho

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sorry but 5.1 is a synthetic fluid as well. 5.1 is a long life fluid while 5 is a shorter life fluid.

I've had AP600 recommended to me as a very high quality silicon race fluid that'll do no harm to the seals. made by lochheed I believe.

regards

Taffy

Wow, this is getting interesting...

Blurb from the AP site:

"AP Racing Brake Fluids have been developed specifically for use under the arduous conditions encountered at the highest levels of motorsport.
All AP Racing Brake Fluids are compatible with all hydraulic brake systems designed to conform to S.A.E. J1703 requirements. AP 600 Brake Fluid is intended for competition use only. AP 551 can be used for either competition or road use.

The new AP Racing PRF 660 has been developed for use in extreme high temperature racing conditions. Conforms to and exceeds FMVSS 116 DOT 4 and SAE J1703 and J1704.

AP Racing Formula DOT 5.1 Brake Fluid conforms to S.A.E. J1703 specifications and is ideal for High Performance Road Applications, Competition and Track Days.

All AP Racing Brake Fluids are Polyalkalene Glycol Ether based and are not a silicone based fluid. AP Racing do not sell and do not recommend using a silicone based brake fluid with any of its products.
Colour variations may occour in AP 600 brake fluid due to its manufacturing process.
This has no effect on the quality and performance of this product."

Looks like good stuff. This fluid is way $$.
However, since it is Glycol based should I avoid it on the clutch side and get silicon based?
This is what I seem to be getting from all this but the front brake uses 5.1.
I am assuming 5.1 is silicon based. Or is it??? :?
It would be great to keep them the same if possible.
I guess the logical question now is, are the seals different on the left and right side?

HusaWhat said:

Looks like good stuff. This fluid is way $$.
However, since it is Glycol based should I avoid it on the clutch side and get silicon based?
This is what I seem to be getting from all this but the front brake uses 5.1.
I am assuming 5.1 is silicon based. Or is it??? :?
It would be great to keep them the same if possible.
I guess the logical question now is, are the seals different on the left and right side? [/color]

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This is what I have said at least once, maybe twice - IIRC. The DOT specification is a specification, NOT a guarantee that the fluid will be silicone based and therefore safe for a Magura clutch MC. If a manufacturer can make a glycol based fluid that meets the DOT 5.x spec then they can sell it as DOT 5.x fluid. There is nothing in the spec that says anything about silicone v. glycol.

Don't assume.

Avoid glycol based fluids in the Magura MCs marked "Mineral Oil".

Use Silicone based fluids instead.

Look further than the DOT specification.

Personally, I wouldn't bother with buying high dollar fluid unless you race and absolutely want the stiffest rear brake feel you can get *and* you have problems with temperature. In which case, you would probably be ahead in taking off the Magura clutch MC and buying the Magura LHRB instead.

I don't like a touchy rear brake. Mine was touchy right off the showroom floor. Just a bit of pressure locked it up regardless of how much traction there was - pavement or dirt. I didn't need more pressure, I wanted less. I wanted more feel. So I purposely let some air into the line between the slave and the caliper and that was about right for me. I can still easily lock up the rear brake, but now it only locks up if I want it to lock up. I don't race or compete in any way, so I don't use my rear brake a lot, so this is fine for me. YMMV.