Note to self: part #45520-300-000 is a cup, not a screen.
So, after this weekend's bike repair shenanigans, I'm thinking we should have a "Bonehead of the Month" award, to go along with all our other awards like MOTY and the mileage awards. I'll certainly be the leading bonehead candidate this month!
My rear brake started dragging recently; the dreaded SMC problem was rearing its ugly head. Once the new part arrived from Partzilla, I enlisted my good friend Jon to help with the brake bleeding.
Bleeding the front brake went fine. After following the procedure in the manual, the lever was nice and firm. On to the rear brake.
Following the shop manual procedure, we got barely a dribble of fluid out of any of the bleed valves. First we tried manually pumping the brake pedal to move the fluid through; no go. Then we tried this bleeder (https://www.harborfreight.com/brake-fluid-bleeder-92924.html); a small amount of fluid came out, but not nearly enough. Finally we tried this vacuum bleeder (https://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-63391.html). Again, a small amount came through, but not nearly enough. The brake pedal had exactly zero pressure. We worked on this for several hours Saturday, and several more on Sunday, checking and double-checking that we were following the steps in the shop manual in the correct order. We could see the fluid go down a little in the rear master cylinder, but again, not very much. All kinds of scary thoughts crossed our minds: blockage in the system somewhere; new SMC was bad; air leaking into the system somewhere; SMC installed wrong, etc. But the hand pump bleeder was holding good vacuum. Very perplexing.
Finally I broke down and messaged Larry the ST Whisperer. I hated to disturb him on the holiday, and asked if I could call him Monday evening for guidance. While waiting for his reply, we went to the garage and tried again. Jon was poking around the rear MC and lifted the screen out. We heard, as Ross Perot called it years ago, a "giant sucking sound," as the vacuum was released and all the fluid in the MC was sucked into the system. Along with a bunch of air, dammit. That screen in the rear MC isn't a screen; it's a cup, or, as the manual calls it, a diaphragm. Oops. Boy did we feel stupid. All this time, we'd just been pulling a vacuum on the system. We could see the fluid level in the MC drop a bit as the bottom of the cup was pulled down by the suction. So we were certain a little bit fluid was going into the system. And we were certainly wrong.
As I mentioned to Larry in my follow-up message, that "giant sucking sound" means we suck as mechanics!
Once we figured out our bonehead error, bleeding the system went fine. It took a long time to get all the air out though. We went through 2 full quarts of brake fluid.
Upon reviewing the manual, I see on page 17-8 it says to remove the diaphragm from the rear MC as part of the process to drain the brake fluid. But I wasn't draining the fluid, so I skipped ahead to the "Brake Fluid Filling/Air Bleeding" process on page 17-9. It doesn't mention anything about the diaphragm.
After we finished the bleeding, I had to get to my family's Easter dinner, so we didn't have time to put all the tupperware back on. At Larry's request I'll call him this evening before re-installing the tupperware and after that I'll be back on the road.
I hereby nominate myself for the new Bonehead of the Month award for April, and would assume I'm the frontrunner by a LARGE margin...
So, after this weekend's bike repair shenanigans, I'm thinking we should have a "Bonehead of the Month" award, to go along with all our other awards like MOTY and the mileage awards. I'll certainly be the leading bonehead candidate this month!
My rear brake started dragging recently; the dreaded SMC problem was rearing its ugly head. Once the new part arrived from Partzilla, I enlisted my good friend Jon to help with the brake bleeding.
Bleeding the front brake went fine. After following the procedure in the manual, the lever was nice and firm. On to the rear brake.
Following the shop manual procedure, we got barely a dribble of fluid out of any of the bleed valves. First we tried manually pumping the brake pedal to move the fluid through; no go. Then we tried this bleeder (https://www.harborfreight.com/brake-fluid-bleeder-92924.html); a small amount of fluid came out, but not nearly enough. Finally we tried this vacuum bleeder (https://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-63391.html). Again, a small amount came through, but not nearly enough. The brake pedal had exactly zero pressure. We worked on this for several hours Saturday, and several more on Sunday, checking and double-checking that we were following the steps in the shop manual in the correct order. We could see the fluid go down a little in the rear master cylinder, but again, not very much. All kinds of scary thoughts crossed our minds: blockage in the system somewhere; new SMC was bad; air leaking into the system somewhere; SMC installed wrong, etc. But the hand pump bleeder was holding good vacuum. Very perplexing.
Finally I broke down and messaged Larry the ST Whisperer. I hated to disturb him on the holiday, and asked if I could call him Monday evening for guidance. While waiting for his reply, we went to the garage and tried again. Jon was poking around the rear MC and lifted the screen out. We heard, as Ross Perot called it years ago, a "giant sucking sound," as the vacuum was released and all the fluid in the MC was sucked into the system. Along with a bunch of air, dammit. That screen in the rear MC isn't a screen; it's a cup, or, as the manual calls it, a diaphragm. Oops. Boy did we feel stupid. All this time, we'd just been pulling a vacuum on the system. We could see the fluid level in the MC drop a bit as the bottom of the cup was pulled down by the suction. So we were certain a little bit fluid was going into the system. And we were certainly wrong.
As I mentioned to Larry in my follow-up message, that "giant sucking sound" means we suck as mechanics!
Once we figured out our bonehead error, bleeding the system went fine. It took a long time to get all the air out though. We went through 2 full quarts of brake fluid.
Upon reviewing the manual, I see on page 17-8 it says to remove the diaphragm from the rear MC as part of the process to drain the brake fluid. But I wasn't draining the fluid, so I skipped ahead to the "Brake Fluid Filling/Air Bleeding" process on page 17-9. It doesn't mention anything about the diaphragm.
After we finished the bleeding, I had to get to my family's Easter dinner, so we didn't have time to put all the tupperware back on. At Larry's request I'll call him this evening before re-installing the tupperware and after that I'll be back on the road.
I hereby nominate myself for the new Bonehead of the Month award for April, and would assume I'm the frontrunner by a LARGE margin...
