Clutch Slipping, easy fix

I tried to flush mine when I got it but I can’t get any fluid to come out. I tried the old school way of turning the bleeder and pulling the lever, put my vacuum bleeder on it and nothing. Sorry for the thread jack

DOT5 and DOT5.1 are not the same and are not compatible. DOT5.1 is not an improvement over DOT5. DOT3, DOT4, and DOT5.1 are glycol based. DOT5 is silicone based. DOT5.1 is compatible with DOT3 and DOT4. Only DOT5 is incompatible with DOT3, DOT4 and DOT5.1.

It is unfortunate that manufacturers have chosen the designation DOT5.1 to represent the next generation of glycol based brake fluids because it can be confused with silicone based DOT5.

To be on the safe side; if your manual calls for DOT4, use DOT4.

DOT4 has a boiling point in the low 300'sF. DOT5.1 has a boiling point in the high 300sF. Most of us will not ever take our brake fluid to either of those two temperature levels. DOT4 will do the job.

Also, I've seen some comments that mention use and mileage as a basis for deciding when to change your brake fluid. As brake fluid is hygroscopic, it can slowly go bad without use or mileage. Hygroscopic means "tending to absorb moisture from the air." As your brake fluid absorbs moisture, the boiling point goes down, making it more susceptible to brake fade. This is why you see warnings about using brake fluid from an unopened container. It will slowly go bad in an open container without use.

It is better to replace your brake fluid on a time basis rather than a mileage basis. The Yamaha Service Manual does not provide a mileage recommendation to change brake fluid. It does provide a time recommendation of 2 years. I do mine annually.

And, all of the above applies to your clutch, too.

I'm not clear on why a clutch fluid flush would affect a slipping clutch unless the slave cylinder was sticking and exercising it as part of the flush somehow loosened it up. Slipping clutches are typically caused by worn or contaminated friction discs and to a lesser extent weak springs.

Ironhand said:

I'm not clear on why a clutch fluid flush would affect a slipping clutch unless the slave cylinder was sticking and exercising it as part of the flush somehow loosened it up. Slipping clutches are typically caused by worn or contaminated friction discs and to a lesser extent weak springs.

Click to expand...

Hydraulic clutches will slip if the fluid is not flushed often enough. First symptoms are a spongy feel due to either air, moisture or both. With moisture in the system the fluid expands and disengages the plates causing slip. I have had this exact problem on both my KTM and Beta when using in extreme rock crawling. I changed to fresh fluid and problem disappeared.

I thought I posted this but I cannot see it I'm new to this.

I will try again I'm new at these forums. A old motocross trick that we would do when they clutch started slipping. We would take one washer and put it On each of the Springs which go into the basket usually 5 or 6. It seemed to always work and saved a lot of money from buying new clutch Springs. The pull was was a little stiffer but hardly noticeable really .

After a clutch plate change, my clutch was slipping so bad it was almost unrideable, getting up to 68 mph max was a slow going process...that bad....

Took it back to the shop, it turned out that the diaphragm was in this shape, i guess someone messed it up in the plate change process. Anyway, all good now, less clutch noise ( 2015 ES model, 49.000 miles, but i was getting a bit too much clutch noise ) and the gears go in like butter....pulls stronger too.

I don't see how that would make the clutch slip

Tenman said:

I don't see how that would make the clutch slip

Click to expand...

It could just be a justification for some mistake on the assembly of the clutch plates that made the clutch slip, but what the shop told me was that due to this, there was insufficient pressure on the system and caused the clutch to be partially engaged.