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I have a 2004 Polaris sportsman HO 500 4x4 atv. Just put new brake calipers, brake lines, and master cylinder and new brake bands. Can bleed and get fluid at both valves on the front right and left but no pressure is building up on the hand lever. Any suggestions or ideas??
 

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I have a 2004 Polaris sportsman HO 500 4x4 atv. Just put new brake calipers, brake lines, and master cylinder and new brake bands. Can bleed and get fluid at both valves on the front right and left but no pressure is building up on the hand lever. Any suggestions or ideas??


Are the front and rear brakes tied together? You may also need to bleed the rear brakes. Is the foot brake also tied into the hand brakes?
 

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The rear brake is operated by the front brake lever as well as the front - try bleeding the rear caliper also - rear caliper has two bleed screws - one for the hand lever and one for the foot system
 

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The upper bleeder should do the hand brake bleeding.
 

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Discussion Starter #6
Can get good fluid to both front calipers and the bleeder to the hand lever on rear caliper but no flluid at the foot control bleeder on the rear. Still no pressure on the hand lever. What can I try now?
 

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There won't be fluid at the rear foot bleeder on the caliper. The rear caliper is operated independently of each of the hand and foot levers.
 

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What could be reason for no pressure on the hand lever? Have bleed many, many times, still no pressure. .???
 

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Anything!!! I mean you could still have air in the lines. The master is bad even though it's new. Did you bench bleed the master first??
 

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What replacement parts did you purchase??? Polaris OEM parts??? Or aftermarket???
 

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OK - here's what works for me when nothing else seems to work:

During this entire process, make sure there is sufficient DOT 4 brake fluid in the MC to cover the ports in the bottom of the reservoir. If the ports are not covered, air can be drawn into the brake piston bore and the process will have to be restarted.

Verify the MC is pumping as designed; do this by removing the line from the MC and plugging the port - just holding your finger over the port will work - with the port open, squeeze the lever, put your finger over the port and release the lever - you should feel a slight pull on your finger as the MC sucks fluid out of the reservoir into the cylinder - without removing your finger, squeeze the lever - both air and fluid should be forced past your finger - do this until you get all fluid and no air - on your last squeeze of the lever, hold the lever against the handle bar, connect the brake line and snug the fitting - turn the handlebar to the right to get the MC at it's highest point - release the lever and pump very gently only moving the piston in the MC about 1/4 inch while watching for a release of air into the MC reservoir - continue this until no air appears - when air is no longer escaping into the reservoir, while squeezing and holding the lever toward the handlebar, crack the line fitting momentarily to release trapped air and some fluid - before the lever is completely depressed, tighten the line fitting - if the MC is moving fluid satisfactorily, you should be able to get some degree of brakes.

At this point the MC is bled and you are ready to bleed the lines and calipers. Starting with the rear caliper; remove the caliper from it's mount and remove the brake pads - pump the master cylinder to push the piston out of the caliper - only push the piston out about 1/2 inch (more than 1/2 inch risks the piston coming out of the caliper in which case this entire process has to b e restarted) - position a c-clamp on the caliper in preparation of pushing the piston back into the caliper - do not push the piston into the caliper at this time - wait about 1/2 hour - now holding the caliper with the line fitting at the apex, operate the c-clamp to push the piston into the caliper - with the c-clamp retaining the piston in the caliper, operate the brake lever - you should feel some to a good amount of resistance when you squeeze the lever and perhaps see the c-clamp or brake hoses flex under the pressure - if not, release the c-clamp, pump the piston out as previously, wait 1/2 hour, depress the piston - repeat as many times as necessary to get good feel and proceed to repeat process for each front caliper.

To expedite the procedure, get three c-clamps, pump the rear piston out and install the c-clamp, but do not push the piston in - remove one front caliper, remove the pads, pump the piston out and install the c-clamp - do the same for the other front caliper and wait about 1/2 hour, then press the rear caliper piston in, followed by one front caliper and then the other. If not satisfactory, loosen the c-clamp on the rear caliper and pump the piston out until it is tight against he c-clamp, then loosen one front c-clamp, pump the piston out and repeat for the other front caliper and wait 1/2 hour - repeat as many times as necessary to get the lever feel you desire.

This is all dependent on the master cylinder functioning properly and holding the caliper so the line fitting is at it's apex when the c-clamp presses the caliper piston fully into caliper body.

Note: a great deal of pressure will not be necessary to press the piston into the caliper. Just a bit more than finger pressure. If you are King Kong, you might be able to push the pistons in by hand, but you still have to hold them depressed to feel the lever pressure. If the pistons resist being pushed into the caliper body and the lever is tight with the c-clamp snug, the master cylinder piston is not clearing the fluid return port in the reservoir. Either the lever is adjusted incorrectly, the wrong lever is installed, the lever needs modified or the piston is not returning fully. If the lever is tight, remove the lever to see if the problem is alleviated - if still tight with the lever removed, investigate the travel of the piston or clear the return hole of obstruction.
 
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