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K75RT - Brake Flush, Motion Pro Check Valve Review
A routine check of the front brake pads on my K75RT showed it was time for a set of new pads. The brake fluid was looking a bit grim as well so I decided to tackle both at the same time. I had last flushed the brake fluid with a Mity-Vac, though for some reason I could never get it to work quite right and resorted to the 2-person old-school method. This time I decided to try a one-way check valve as I'd heard it was a great solution for a 1-person brake flush.
After a bit of searching I found the inexpensive plastic one-way check valve on Amazon that had been recommended on a few K-Bike enthusiast sites. Looking a bit further I found a metal one made by Motion Pro that cost a few dollars more. As both were pretty cheap, I bought both. I also picked up the inexpensive (ok, cheap - $2 with coupon) 1-person brake bleed kit at Harbor Freight that basically consists of 5' of clear tube and a catch container. Lastly, I got a liter of Repsol Dot-4 brake fluid. I threw in a $10 set of Stanley punches for good measure as my old brake pin driver outer punch had developed a serious bend. I rounded out the kit with a couple free cedar shims from Home Depot (great way to quickly and easily recess the pads) and a free infant oral medicine syringe from CVS for emptying out master cylinder reservoirs.
The Motion Pro Check Valve arrived and looks and feels like a well-made, solid quality product. It is clearly engraved with IN and OUT to identify the fluid flow and comes with two 6" lengths of clear hose. It worked perfectly and I'd heartily recommend.
The front brake pads were easy and the new, longer punch worked great. For the brake flush I took an empty 1-liter water bottle and made a small hole in the cap. One end of the long hose went into the cap with enough inside to curl around the bottom, the other end went to the OUT part of the Motion Pro metal check valve. I used the short 6" or so hose that came with the valve to go from IN to the bleed nipple. I started with the left side ABS coffee can. Following great advice found here and elsewhere I removed the front reservoir cap and used the syringe to empty it, then refilled it with fresh fluid. I wrapped a thick hand towel around the grip to keep from pulling the lever too far in and risk damaging the seal, cracked open the bleed nipple and start pumping. Slow and steady, the fluid immediately began marching up the tube, through the valve, and into the water bottle. It literally couldn't have been easier. I kept pumping and adding fluid to the reservoir when it got low until I could see the fluid coming out turn from dark and a bit cloudy to nice and clean. Then I simply closed the bleed nipple and moved to the front caliper, and repeated. The back ABS can and caliper were the same, as easy as could be.
The entire process, pads and flush, took less than an hour and I cannot recommend enough the Motion Pro metal check valve - it worked absolutely as advertised and made the whole process simple and quick. If you haven't changed your brake fluid in a while and have a bit of trepidation doing it yourself, try this valve - it is literally easier than changing the oil! You don't need to replace the pads to do this, but it helps having new ones in there to minimize fluid retained in the calipers.
"A good stick is a good reason