No, but it removes some concerns. It is difficult to diagnose issues from a distance. The SMC has been replaced and you will have had to have flushed everything out then, and providing that rubber boot has not been disturbed, it will not have got any water in. (It is very difficult to get the rubber boot back into position properly, once it has been disturbed -
link ). The SMC in the photo was a friends who fitted a brand new service kit just two years prior to these photos. I don't believe that the seal was made properly with the top hat rubber boot.
I give mine a good flush every 12-18 months. However, I did once get a blockage in the line from the SMC to the PCV bleed valve. I never saw it come out, but the pressure released suddenly after which the fluid moved freely. I don't think the PCV pressure valve would be the issue - fluid flows in and out of that easily. Its only when the pressure increases that it allows a piston/spool to be pushed in taking some of the pressure away from the line.
Next time it does it (if it does) it would be worthwhile closing up the valve and just checking - is the pressure applying the rear brakes. Does it release the rear brakes when you remove the pressure from the pedal ? I'd be tempted to look at that bleed valve. If you have teflon tape around the threads, it may have disintegrated and blocked the hole in one side at the bottom of the threads. When you remove it, unscrew it a bit by hand or with a small socket between finger and thumb and screw it back in a touch. Forward and backward - just to feel that the threads are ok and not binding. You don't want to cross thread it when you put it back in.
So, today I went ahead and went through the whole process again.
Last time, I used the old method of pumping the appropriate lever/pedal for the current step a few pumps, then holding that pedal/lever down, then cracking the appropriate bleed nipple (and feeling the lever/pedal sink as the nipple opens), and then closing the bleed nipple before releasing the pedal/lever.
Well, today I decided to try something slightly different. I tried the method that the forum member with the YouTube channel name "GTs Garage" used in his video. He attached the 8mm wrench and a piece of clear tubing, held the tubing straight vertically, cracked open the appropriate bleeder valve for the current step, then repeatedly pumped the appropriate lever/pedal/SMC for the current step, then finished with closing the bleeder nipple and removing the tube/dumping the brake fluid from the tubing into a bottle.
I wanted to try this method to ensure that I was really puling a good amount of fluid through the system on each brake line/bleed nipple--especially the last nipple for the rear outer pistons that I had the strange issue with last time.
Well, I think because I went through the whole process extensively last time, when I bled each nipple today only clear and clean fluid free of air came out of each one. I ran about half of a reservoir of brake fluid through each bleed nipple this time (and about a full reservoir through each one last time). This time, when I cracked open that last rear outer piston bleed nipple, I went back and forth pumping the foot lever and then the SMC while the bleed nipple was open to make sure that I was moving fluid a good amount of fluid, and this time there was no obstruction of flow, and only clean and clear fluid free of air moving just as easy as the fluid was moved in any of the other bleed nipples/circuits. So, personally, I think I'm feeling good that the system is now free of any dirty fluid, and air.
I cleaned everything up, then tested that the brakes fully engage and fully disengage when using the pedals/levers. Then, I layed on the ground next to the bike, turned the rear wheel forwards with my foot as I used my hand to engage the SMC to make sure that it would lock the rear wheel--and more importantly, completely release the brakes on the rear wheel when I let go of the SMC. Thankfully, it worked just as it should! Also, if I give it a good spin, the rear wheel rotates about three times around on its own without any brakes applied--just to get an idea of any drag/etc. present.
I know it's tough to make a call without seeing it in person, but would you guys agree with my thoughts that this brake system is now good?