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[Dusty]

Yesterday morning I put my front wheel back on after having a new tire mounted. During the process I had pushed the pistons on the calipers in and ended up knocking a brake pad loose and had to take a caliper off to reinstall the pad. I never took any brake lines loose. Just put the pad on a remounted the caliper.

When I got it all back together, I spun the front wheel, listened for rubbing etc and tried the front brake. Worked great. I had to squeeze the handle a couple of times but I thought that was because I had pushed the pistons in.

Took the bike off the jack and eased out of the yard and out of the neighborhood. When I came to the first stop sign, I pushed my brake pedal and had NO BRAKES! I grabbed the front brake and luckily stopped.

I pumped the foot brake and after 3 or 4 pumps it firmed up and worked fine. I'm just glad I wasn't hauling Cranberries up to that stop sign.

I know the front and rear brakes are linked but what I don't understand is if I didn't take anything loose to let air in or fluid out of the system why did I have to pump the rear brake pedal to pressure it back up. Where did the pressure go? My fluid levels are good and my brakes had been working fine and still are.

I was so focused on my front wheel that testing my rear brake never crossed my mind. So, to you do it yourselfers, no matter what you do to the brakes, test the whole enchilada before you ride.

Bill

[snake]

It never woulda' occurred to me that it might mess up the rear, either, Bill. Tks for the heads up!

[Tinman]

Makes sense to me. I thought the brakes were linked? I would definitely test both.
Bill, did you do your valve adjust yet? You do realize I have your 4mm wrench right? Call me if you need me to bring it over. 670-2794.

[twistedrcpilot]

I've had so may weird occurances I've made it a point to do a preflight check every time I work on somthing.

I too had the brake issue and thankfully I caught it before I hit the road.

[Dusty]

Makes sense to me. I thought the brakes were linked? I would definitely test both.
Bill, did you do your valve adjust yet? You do realize I have your 4mm wrench right? Call me if you need me to bring it over. 670-2794.

I'm just wondering if I had air trapped in the system somewhere that found it's way out when I was turning the caliper around? I thought I bled them real good the last time I changed fluids. I definatly will check both front and back from now on, it just didn't cross my mind since I had not done anything that would/should have affected the pressure in the system. At least I didn't think I did.

Anyway, yes I did remember that you had the 4mm but I got by with out it. It took me three times but I finally got them right. I hope. It still runs and doesn't sound like a bunch of marbles in a coffee can like it did the first two attemps. 

Bill

[Tinman]

BTW, I bought a set of tuning wrenches on ebay and they had the 4mm wrench so when I see you next I will have it in my bag. Thanks and if you ever need help just give me a call.

[Dusty]

BTW, I bought a set of tuning wrenches on ebay and they had the 4mm wrench so when I see you next I will have it in my bag. Thanks and if you ever need help just give me a call.

Thanks James! 

[RobDogg]

Pretty simple and expected.

The rear brake is linked to the center piston of the front calipers.  When you tested your front brakes you forced the outer pistons on the front calipers out as they should be (from you compressing them). However, the center pistons on the front calipers were still retracted (they're only actuated by the rear brake pedal).  So when you came to your stop you were pumping the center piston back into its proper position.

No harm, no foul, you're good to go now.

[Dusty]

So until all the front pistons are back out you won't have anything in the rear?

Thanks for the response, makes sense!   

Bill