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I have a new master cylinder upgrade brakes and they won’t hold pressure so to stop I have to pump the brakes over and over and even then it’s very slow to stop. I’ve bled the brakes and still nothing. Helpppp!!! 1994 Honda fourtrax 300
 

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i use 3 feet of plastic hose for each brake hub—gotta fit snug on the bleed nipple. Press a hose end over each bleed nipple. Key is that brake fluid has to stay in the hose to prevent air from getting back in past the nipple. So route both hoses up from the bleed nipple, up and over the A-Arm and then down into an oil pan.

get those brake shoes adjusted so you know they’ll contact the hubs.

Remove the black rubber puck from inside bottom of the master cylinder. Use rags to Get that master clean cylinder —don’t let any sludge go down into the lines. Make sure the piston fluid supply and relief ports are clear. I use shop rags and plumbers flux brushes to remove all the sludge.

i use a whole bottle of fluid to flush the lines. Just keep the master cylinder reservoir full. Start with the brake furthest from you—if you are less than 6 feet tall, you most likely cannot do this next step by yourself.

Squeeze front brake lever and keep pressure on it, slightly open a bleed nipple to relieve pressure and close bleed nipple before the lever goes fully to the handlebar. If system is empty your lever may go to the bar several times while you chase out the air. Repeat until you’re getting clean fluid at each bleed nipple. you should start to build good pressure.

residual air is always going to try to rise in the line—it actually gets trapped in the bow of the hose just behind the master cylinder. adjust the hose and maybe handlebar slightly to get air to move directly to the master cylinder. Careful keep that master cylinder fluid from spilling
jiggle the brake lever and you’ll see bubbles rising from the master cylinder relief port.


once you have good pressure, readjust the brake shoes.

if the brake fluid Was really dirty, I will let the new fluid stand overnight and then reflush the system.
 

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1998 Honda Recon TRX 250
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Have you completed your brake flush properly? If so, have you tried adjusting the front brakes? Specifically parts 13,14,17,18 on the diagram attached? The brake shoes have to have a little bit of resistance against the hub and you have to play around with it untill it feels right. If those components are rusted, you have to take off the front hub and clean or replace the components listed. I found that that rotating each out until it has solid resistance against the hub and then backing them off a click works like a charm.
 

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Goober has a lot of good information. I adjust 1 shoe correctly, then tighten the adjuster on the other shoe and leave it tight. The less the shoes move the easier it is to bleed. When I finish bleeding then back off the 2nd shoe a couple clicks so it will roll.
 
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