Motorcycle Repair: Brakes, shucks auto supply, hand vacuum pump

Question
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Followup To
Question - still can not get any pedal,do both masters have to be open to do this? thanks
Have a 1986 venture 1300,Replaced the rear pads ,bled till clear ,but still have to pump 5-6 times to get pressure ,but still wont lock rear tire . Please help!
Answer -
Hi Fred, I would have to suspect air in the system based on the fact that the brakes can be pumped up. You will have to mighty vac the system. At most Shucks Auto supply stores they sell a hand vacuum pump system. It comes with a hand held vac pump with a gauge and a catch cup and a few other accessories. This unit is connected to your bleeder, you pump up the vac then crack the bleeder and the fluid is drawn through your brake system rather than pushed. The fluid is caught in the catch cup which is inline between your bleeder and the vac pump. This is how a motorcycle tech does all his hydraulic bleeding. Auto Techs are starting to use this system as well as it is superior to pummping the system. This unit is approx $50.00 but worth it. Also try tapping the caliper with a small ball peen hammer to release any trapped air. The fact the rear brakes wont lock, besides the soft pedal, is those pads need to be "bedded in" before they have any real grip. Bedding them in involves several hard stops with just the rear brakes(assuming the hydraulics are solid)which removes the glaze on the rotor and mates the new pads to your rotor. After a few hard stops the pads will begin to bed and grip will improve. If the vacuum pump still doesnt get your pedal back, then check for leaks around the bleeder very carefully. Dry the area around the bleeder and have someone pump the rear brake pedal while you watch and listen for a leak. Lastly, when you pushed the piston back on the caliper to fit your new pads you may have damaged the master cylinder if you didn't crack the bleeder first. I hope this gives you some additional help.

sincerely
         Randy


Answer
Hi Fred, Ok I need to know two things..first: does your bike have Linked Braking? Two: Did you crack the bleeder before you pushed the caliper piston back into the caliper? If you didn't {and dont feel bad it happens to the best of us)you probably forced all the real nasty contaminated fluid that sits behind the caliper piston, back into the master cyclinder, which may very well have ended it's 18 year career. If you have linked brakes...and some of those big boys had it back then, and didn't crack your bleeder FIRST then you may have just stacked the equilizer line with air. In that case you would need to bleed out the fronts then the equilizer then the rears. I am not positve on the exact procedure as I am more of a sport bike nut but I really want to help you figure this out. So, linked brakes?? Cracked the bleeder open before depressing caliper piston???  keep me posted

randy