Why brake fluid, why not hydraulic fluid?

[Peder_y2k]

For the clutch system, why brake fluid instead of hydraulic fluid?

I know for brakes, the fluid can get very hot from the brake friction, but the clutch mechanism is not subject to high heat, so why not use hydraulic fluid? ('88VR clutch system) Does water absorption have something to do with it?

Inquiring minds want to know..........

-Pete, in Tacoma WA USA

[Flyinfool]

Brake fluid is hydraulic fluid.

By using the same fluid as the brakes, there is one less type of fluid to be stocked and installed by the factory.

There is no chance of using the wrong type fluid in the wrong reservoir by either the factory or the owner.

There are components in the system that are shared between the brake and clutch, if different fluids were used the specs of the shared parts may need to be different thus increasing the number of stocked items and the possibility if installing a wrong component in the wrong system.

 

Water absorption is not an asset, it is a bad thing, but not bad enough to use something else.

 

Bottom line is that it is cheaper to use the same fluid and it does get the job done.

Stocking units are a big deal to a large company.

 

Besides, if you spill some of most hydraulic fluids on the plastic or paint it just makes a mess that has to be wiped up, if you get messy and spill brake fluid on your plastic or paint, they get to sell you new parts.

[Peder_y2k]

It has been my impression that brake fluid will absorb water so that the water will not pool in the cylinder and cause corrosion. That's why the mfr. suggests a regimen of flushing every couple years, so as to remove the water before the fluid becomes saturated with water and pools.

I'm beginning to think about switching fluids for the clutch, since I'm now repairing the system and have it open. The advantage of using hydraulic fluid (jack oil, ATF, etc.) is that one can use waterproof grease to help seal the dust covers etc. keeping water out. Brake fluid seem to be incompatible with grease.

 

Please feel free to correct me if I'm wrong.

-Pete, in Tacoma Wa USA

[MiCarl]

Are you sure all the seals and lines are compatible with your alternate fluid? How about the viscosity, will it be correct to work with all the ports, passages and orifices?

 

DOT4 is very inexpensive. Why not just change it every couple years and put your effort into something more productive?

[Sylvester]

:sign yeah that::sign yeah that:

 

 

[Guest tx2sturgis]

I use clutch fluid in the clutch side. Brake fluid for the brakes, blinker fluid for the blinkers. I thought everyone did!

 

 

I dont have the clutch fluid container handy, but the blinker fluid bottle looks like this:

 

 

 

 

[Peder_y2k]

'Cause I wouldn't have to change it every couple years. I could ignore it like my cars automatic transmission fluid that I will change at 150,000 miles, or 15 years whichever comes first.

-Pete, in Tacoma WA USA

[Squidley]

Pete,

 

If your going to go that route, make sure as Carl mentioned that the fluid your going to use is compatible with the oring material that is in the components. Buna, nitrile, viton all have different characteristics and some fluid will attack and degrade them.

 

Best bet, and easiest to do, is a fluid change every year. I do it on all my bikes, and can have all the systems flushed with new fluid in 30 minutes or less. I know your wanting less maintenance, but motorcycles just dont work the same way as an automobile, and contrary to popular belief, auto's have a scheduled maintenance on the brake system fluids....

[k9cottage]

i am not sure if water is a problem in auto trans fluid and an auto box is not a sealed unit so if water did get in it would just boil off with normal running but a clutch system is a sealed unit and does not get hot it might be worse than brake fluid for water contamination

[Big Lou]

hydrau;ic fluid gets thick in the cold

 

brake fluid dont

 

 

can you say, " clutch slipping":080402gudl_prv: