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I posted another thread about a week ago but it has died so I thought I would try a new one. There's a fall festival this weekend that I would really like to ride in.

On my last ride, I lost all my brakes, as in the lever went to the handlebar and didnt stop. I got home and realized fluid was pumping from the upper reservoir to the foot brake reservoir and vice versa when I pumped either brake. I replaced all pads and my rear caliper, and it didnt help. Fluid is still pumping between the two reservoirs and I have no resistance at the levers. I agreed with the advice that I got here, in that the only place the fluid from the upper and lower systems meet is at the rear caliper. So I'm wondering if I could have gotten a bad caliper, or if a bad master cylinder could cause the same symptoms? I am removing the masters right now to try visually inspecting them but would love some advice on what could cause this. I have bled the brakes with a mighty vac, and even tried a zip tie on the foot brake overnight to get any air out. The brakes bleed fine, and they do grab when I squeeze the lever, just not enough to provide resistance at the lever. I would think that SOME resistance should be there if everything was working properly but I still had air in the system. I also hear a bubbly sound in the rear caliper when I push the foot brake. Its faint, but I hear something in there whether its air or just fluid moving.
 

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It's fluid (maybe with some air) moving from one chamber of the rear caliper to the other chamber of the caliper. Obviously you did not get a NEW caliper and bought someone else's problem. Get a seal kit (part number 2201872 $60) at your friendly Polaris dealer, install the kit and your problem should be solved.

If you did get a new caliper, take it back to the dealer and have them repair or replace it!
 

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Discussion Starter #3
Yeah it was a new caliper. They had to order it for me. It ran out of fluid completely in the woods that day, so I was thinking perhaps I ruined a seal or something in one of the master cylinders. But if the ONLY place the systems meet is at the 2-step piston on the rear caliper, it almost has to be that rear caliper. I can literally watch fluid rise in each master cylinder when I pump the opposite brake.
 

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Man I know you don't want to throw parts at it $$$$$$ but the Masters have been known to go bad. So either rebuild it or pony up the dough for a new one.
 

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Ok - I've been proven wrong before....... So @bp405 - please explain how the fluid from one master cylinder gets to the other if it is not bypassing at the seal on the caliper piston.
 

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Discussion Starter #6
Yes please explain!

I have another development as well. I actually have the rear brakes working fairly well. I took the rear caliper apart, lubed the seals with fresh brake fluid, and now the rear caliper is working well WITH the foot brake only. The hand lever is still pumping fluid to the lower reservoir, but I did get a little resistance with it as well after some pumping. It does however lose the resistance after sitting, and I end up with a puddle of fluid under the rear reservoir where it pumped fluid down and overflowed. I hear a "clicking" noise from around the junction box by the fuel tank also.
 

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Latebird and Scott i was one of the first if not the first to say the rear caliper was the intersection of the two systems and to look there first as Scott did. And he came up with ?????? nothing!!!!! To our surprise!!!! So I have, just did, and again going to say it may be worth the OP's while to look into the master cylinder. Reason being as I have already simply stated they are known to go bad. They're not common but it happens. Also indirectly the master will cause you problems because when it goes bad won't bleed properly. Starting to make sense. If air is trapped and air will move where fluid can't you can have the two independent systems pushing and pulling from one another. So Scott you sound like a pretty mechanically inclined guy and I'm giving you the benefit of that doubt. I'm also going to ASSUME the NEW rear caliper you installed was done properly and was without defect. So again look at the master!!
 

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If that "new" caliper was NOS and has been laying around on a shelf for 14 years the seals may have hardened up. They will soften and swell a little from exposure to brake fluid after a while. That may explain why it has started working some after a couple days...which also brings up another question... Somebody before the OP may have put some kind of off-the-wall fluid in that may have caused the issue with the original caliper??
 

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I'm no specialist by any means, just trying to help...

The foot brake was built to be used in an emergency, if the handbrake fails is my best understanding of there design... now based on that thinking

If it's a 2 step caliper, does it also let fluid back into the handbrake system to activate the front brakes when you hit the foot lever, in the event the hand brakes failed? If so could it be something as simple as the 2 brake lines being crossed at the caliper?
 

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In my learned opinion - no

Crossing the lines simply means the chambers are inverted - the seal for the smaller diameter of the piston has to be leaking to let fluid from one master cylinder to the other master cylinder. Using the hand lever applies all three brakes and using the foot lever applies the rear brake only
 

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Scott what's the status on your brakes???

Another thread has been started by another gentleman with a similiar issue.
 

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I'm no specialist by any means, just trying to help...

The foot brake was built to be used in an emergency, if the handbrake fails is my best understanding of there design... now based on that thinking

If it's a 2 step caliper, does it also let fluid back into the handbrake system to activate the front brakes when you hit the foot lever, in the event the hand brakes failed? If so could it be something as simple as the 2 brake lines being crossed at the caliper?
On my '99 Scrambler the rear brake line has a flat spot on the top of the fitting at the caliper, allowing room for the front brake line, when switched, they won't connect because the line for the front brakes doesn't have that flat spot and therefore doesn't have clearance to connect.
 

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On my '99 Scrambler the rear brake line has a flat spot on the top of the fitting at the caliper, allowing room for the front brake line, when switched, they won't connect because the line for the front brakes doesn't have that flat spot and therefore doesn't have clearance to connect.
Need a pic - the lines are about an inch apart - should not be any interference - even if they are switched it has very little effect on the brake operation.
 
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