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Guest notmyname
Posted

OP

 

Don't listen to all these stories.

Go to your bike and kiss your brakes.

 

Dot oil is aggressive stuff, violent if you wish, slap a few drops on your clothes, kitchen floors, car's bodywork and especially plastic and see how volatile the stuff is.

 

 

After you have kissed your brakes.

Follow it up with a goodbye .

The brutal truth right here folks.

Posted

OP

 

Don't listen to all these stories.

Go to your bike and kiss your brakes.

 

Dot oil is aggressive stuff, violent if you wish, slap a few drops on your clothes, kitchen floors, car's bodywork and especially plastic and see how volatile the stuff is.

 

 

After you have kissed your brakes.

Follow it up with a goodbye .

Never mind kissing his brakes, OP really should bend over and kiss his @ss good-bye.... For all the reasons said above, Shimanos cannot be rebuilt, the damage has been done to the seals and its now only a matter of time before they fail, just pray it does not happen approaching a red light / middle of a rock garden, :-(

Posted

Hi hubbers

 

So what is the difference between motor vehicle disk brake fluid (SAE 10)  and the Shimano mineral oil sold by LBS ?

 

Price for sure !!! 

 

Is there any reason why can I not use motor vehicle disk brake fluid in my Shimano hydraulic brakes ?

Have had to do so in an emergency over the weekend and it seems to work fine.

Any posssible long term negative effects that anyone knows of ?

 

Should have asked this question before using the Dot fluid in the Shimano brakes and not after.

Posted (edited)

OP

 

Don't listen to all these stories.

Go to your bike and kiss your brakes.

 

Dot oil is aggressive stuff, violent if you wish, slap a few drops on your clothes, kitchen floors, car's bodywork and especially plastic and see how volatile the stuff is.

 

 

After you have kissed your brakes.

Follow it up with a goodbye .

That's what I would have said too. What do you make of the alternative oils that people have suggested in the thread? Any good or is it a case of getting what you pay for with these mineral brakes? Edited by James Mulholland
Posted

That's what I would have said too. What do you make of the alternative oils that people have suggested in the thread? Any good or is it a case of getting what you pay for with these mineral brakes?

I dont want to speak on behalf of wyatt but for me, I only bleed with shimano mineral. Why, well shimano says I should...maybe its mass produced somewhere, maybe shimano knows something about the internals of the brake and there is something special in their red oil....who knows. I bought a liter of the shimano oil when buycycle(was like 200 rond I think) was running a special. Gonna take a while to get through it since I only bleed maybe once a year.

 

See if something goes on the brake I won't have this thought in the back of my mind that it could have been because I was taking shortcuts

Posted

This post got me thinking. What is brake fluid. There is no chance i would put it in my bike brakes, personally I would avoid getting brakes that need DOT 4 fluid, nasty stuff. So what do I know, brake fluid is special cos it doesn't boil easily, car brakes have to dump a LOT more energy than little bicycle brakes (Kinetic energy = 1/2 x MASS x VELOCITY SQUARED).

 

Anyway looking on the internet DOT 4 is

 

 

Characteristics of common braking fluids[1]   Dry boiling point Wet boiling point Viscosity limit Primary constituent DOT 2 190 °C (374 °F) 140 °C (284 °F)  ? Castor oil/alcohol DOT 3 205 °C (401 °F) 140 °C (284 °F) 1500 mm2/s Glycol Ether DOT 4 230 °C (446 °F) 155 °C (311 °F) 1800 mm2/s Glycol Ether/Borate Ester DOT 5 260 °C (500 °F) 180 °C (356 °F) 900 mm2/s Silicone DOT 5.1 260 °C (500 °F) 180 °C (356 °F) 900 mm2/s Glycol Ether/Borate Ester
 

 

As you can see its glycol ether (not totally sure what that is) but it is definitely not mineral oil with is just "simple" Hydro carbon chains

 

Anyway that has calmed my inner nerd!!!

Posted

That's what I would have said too. What do you make of the alternative oils that people have suggested in the thread? Any good or is it a case of getting what you pay for with these mineral brakes?

First off.

I love, wait I adore home mechanics, they do everything so right and so by the book.

I have seen some of these guys come and gone, they look for a holiday job, tell the LBS they know everything and within the first two weeks they drop rocks in their rods because they have never seen so many tools and then they walk around red faced all day because they have come to the realisation they actually know very little.

 

Shimano

What a great innovative yet very underrated company, too often they get accused of wanting to monopolise .

They almost perfected bicycle hydraulic brakes whilst everyone else were still trying to develop disc brakes for bicycles.

 

I recall around 2001 my mate Wes called me as he wanted his XT four pod piston brakes bled .

His dad was one of the importers back then and the set he had was already pretty ragged and took some abuse, they were a demo set and besides that, Wes did not play with his bicycle.

The brakes had four pistons per calliper and they came out with a 2 finger lever and wait for it, braided hoses.

 

Get your hands on a set of these and you have gold .

I paid at that stage, the most I have ever payed for any two little bottles of fluid, an expensive bottle of cognac would have been cheaper.

 

I bled the brakes for him, I was at his dads office last week, that same set of brakes is still on a bike and doing a sterling job.

What is the point I am trying to make ?

Shimano as a company are exceptional at what they do, everything they do gets done with massive amounts of engineering and design around it.

When they develop a particular fluid for their brakes, then we need to know that there is just no alternative, regardless of the cost.

 

These mega companies have always and will always know better than any layman out there.

James, sorry if this bored you ,but I just had to get that off my chest  :thumbup:

 

Now back to your original question.

Magura blood is a great alternative, but horrible expensive too.

In an absolute case of emergency, cooking oil or olive oil will also do the job, but bear in mind that a complete system flush will be required after that .

Posted

After reading this thread yesterday, I decided to take a look at my XT-brakes last night as they kept on getting air in the system. I bought the bike 2nd hand in March this year and only started having trouble with the brakes about 2 weeks ago and didn't get round to looking at it till last night. Front brake has yellow fluid in and the rear brake has clear fluid inside? Seem to be leaking oil from the lever of the rear brake as there is a oily/muddy buildup where the lever goes into the housing (don't know how to describe it in any other way).

 

My question is, is there a way to determine what the fluid is inside the brakes and would you advise me to get the Shimano mineral oil? Where can I get Shimano mineral oil as the bike shops here and in Polokwane say they have in stock but don't sell it. They want to charge me to bleed the brakes themselves, and I don't have the time to drive the 65km and wait around till they get to my bike to solve the issue.

 

Any advise will be appreciated. 

Posted

After reading this thread yesterday, I decided to take a look at my XT-brakes last night as they kept on getting air in the system. I bought the bike 2nd hand in March this year and only started having trouble with the brakes about 2 weeks ago and didn't get round to looking at it till last night. Front brake has yellow fluid in and the rear brake has clear fluid inside? Seem to be leaking oil from the lever of the rear brake as there is a oily/muddy buildup where the lever goes into the housing (don't know how to describe it in any other way).

 

My question is, is there a way to determine what the fluid is inside the brakes and would you advise me to get the Shimano mineral oil? Where can I get Shimano mineral oil as the bike shops here and in Polokwane say they have in stock but don't sell it. They want to charge me to bleed the brakes themselves, and I don't have the time to drive the 65km and wait around till they get to my bike to solve the issue.

 

Any advise will be appreciated.

Gerrie

 

Shimano's oil is red / pinkish...definitely not yellow or clear. So just to be safe...YES go get them bled with shimano fluid.

 

Also if there is oil leaking from your lever it isn't good...either the person that cut the hose and installed the olive did a *** job or some seal has gone...lets hope its just a badly cut hose / installed olive. Let the LBS sort that out for you as well.

Posted

Gerrie

 

Shimano's oil is red / pinkish...definitely not yellow or clear. So just to be safe...YES go get them bled with shimano fluid.

 

Also if there is oil leaking from your lever it isn't good...either the person that cut the hose and installed the olive did a *** job or some seal has gone...lets hope its just a badly cut hose / installed olive. Let the LBS sort that out for you as well.

Thanks rouxtjie

 

Will make a plan to get the bike there. Just wish I had a LBS, lol. Not so local for me.

Posted

It's your brakes for crying out loud why would you mess around with something that is directly related to your safety and physical wellbeing?

 

I know the old Oom would still berate me for this but those kind of jobs that I very rarely need done and are important I go to a trusted LBS (yes there are more of those around than most believe) and get them to do it properly and it doesn't cost a houses money :excl:

 

#skudmykop

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