Originally Posted by Ridewva

Most high performance cars (BMW for instance) advises brake fluid changes every 2 years. But cars have a lot more fluid capacity which means it takes longer for moisture to saturate the fluid. They can tolerate neglect better than motorcycles.
There are many drivers who have to change brake pads and rotors more frequently because the calipers are dragging. Eventually the corroded caliper pistons are diagnosed and they get to buy new brake calipers. When asked how often they change their brake fluid, they say never.

Originally Posted by Morris9982

You do not want to pump out the old fluid and then start the new fluid.

If you do that you will fill the system with air and you will have do do a lot more work to pump all the air out of the system.

Remove the reservoir cap and start pumping out the old fluid. Refill the reservoir with new fluid as needed to prevent it from going too low and sucking air into the system.

Keep pumping the fluid through until you see clean fluid coming out. If you have two calipers on the front wheel do one until clean fluid comes out and then do the other. The second will not take as long as you will have already purged part of the system. Close everything up and clean up the mess and you're done.

There are a number of ways to flush the fluid including the old apply brakes/open bleeder/shut bleeder/release brakes method. This works but can be awkward unless you have really long arms or have someone to help. Vacuum systems that pull the fluid through the open bleeder are popular because you do not have to pump the lever. You still have to watch the level in the reservoir so it does not run dry.

I have tried a couple different vacuum systems and could not get them to work to my satisfaction. The ones I tried pulled air through the threads of the bleeder more than they pulled fluid through the system. There is a good chance I was not doing something correctly but I do not know what it was.

On my last two bikes including my current one I installed Speed Bleeders. These bleeders replace the factory bleeder valves. They have a one-way check valve inside. To use, you open them about a quarter turn, attach a tube and collection bag or bottle, and simply pump the brakes. The one-way valve prevents air from entering the system. Everything else works the same (pump until you see clean fluid, keep the reservoir full). I bought the stainless steel versions and I think they were $10 or $15 each. My bike took three, two on the front and one on the back. With these installed I can easily and quickly flush the brake fluid by myself.

You can order Speed Bleeders directly from the company (do a search for their web site) or from various distributors.

I am not sure what your manual states on the brake fluid change frequency but for most vehicles it is once every two years regardless of mileage. The reason for the two years interval is because standard type 4 fluid can absorb moisture, whether being ridden or not.

I hope the helps.

Originally Posted by Rick-e

When was the last time you flushed the brake system in your car or truck? Just wondering...