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Brake bleeding woes

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Replaced my brake line at the front with a stainless one, I have got fluid coming out at the bottom bleed hole . When I close the bleeder she won't pump up at all. Right now I am going to let it sit overnight with the res. cover off so hope fully some air will come out over night. Help me if you can.....I have never experienced this before and I thought I was a mechanic!

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they are a pain that's why it is best to use a power bleeder and some times they are still contary.the puppy's seem to make air,

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I take my caliper off the fork and set it on a steel bar a little wider than the disk in a vise on my work bench. the caliper is just a little higher than the master cylnder like this, and it seems to make pushing the air out a little easier. Gotta have the bike real close to the bench for brake line to reach, and to be able to work the lever and the bleeder at the same time. Hope this helps. 😢

Craig

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I am getting no pressure buildup at all! I took the caliper off and hung it up so that it was higher than the lever. Could it be that the master cylinder is blown? My front brakes were becoming worse and worse (spongy) a fellow rider suggested that I replace the brake hose to get the lever feel back now I have lost the lever altogether! I just ordered a master cylinder rebuild kit from service honda. I hope I can figure this out so I can ride this weekend!

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Jason, try keeping the lever pulled in overnight. For some reason, this always works for me.

It seams to take forever to ge tall the air out of the line after working on the system.

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I am going to pull the whole assembly (lever, caliper) off and bring it in to my work and let our mechanics mess with it. I just hope I can ride this weekend......we are running out of nice weather in the midwest!

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You can't always use the "Pump-it, pump-it, hold-it" mentality like you can with cars. I know, I was an Auto Mechanic for 3 years at a dealership and learned the hard way when attempting this on a motorcycle. The master cylinder piston is VERY small on a motocross bike, hence, the difficulty getting it to drive the air out by pumping the lever.

That's why I suggested the MityVac or something equivalent. They pull a vacuum on the system which draws the air out from the bleeder screw.

This takes a few minutes versus what you're trying to do.

Best of luck.

PS: You might also try a Speed Bleeder fitting. Basically, it's a one-way bleeder screw. This would make it even easier to bleed the system using a MityVac as there would be no way for air to be drawn back in through the bleeder screw.

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I use a simple pump off of a plastic bottle of gear oil. It's free cause it's already in the garage. Clean it well. Push the brake fluid in from the zirc fitting on the calipper. Works every time and it's cheap! 😢

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I have one of my companies mechanics looking at it right now.....He used to work at a cycle dealership. He says that if you don't get all of the air out of the master first it will never pump up. He also told me that it can be a pain in the a$$. I will wait and see what happens......

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I second the Mity Vac. I had a KTM with a hydraulic clutch and could never bleed it correctly until I got the Mity Vac.

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I bet you anything your piston seals on your front master cylinder are torn or messed up. You can bleed all day long, but if they are torn, you'll never get pressure! I see you ordered the rebuild kit. CRF450's have a small resevoir, which causes the brake fluid to boil, and after a while your seals will fail. Especially if they have gradually become spongy, and then just failed. Replace the seals bro, and I know you will get brakes back, especially knowing a new brake line didn't work! Been There Done THAT!!!!!!!!! 😢

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Thanks for all of your replies........I can't get the rebuild kit fast enough and the track that I was riding on last uses a lot of brakes. I also let a guy ride my bike who bought an Alessi 450 from Terry Varner...this guy used to race pro supercross in the early 90's....he can do things on a dirt bike that I can never do. The brakes got very hot that day.

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Update: finally got it to work......Our shop mechanic used a bleeder that hooks to a air compressor to suck the fluid through but he found the banjo bolt up by the master was leaking air ( I didn't wan't to overtighten ) and if you look inside the res. there is a little plastic plate with some very small holes in it ....he said almost all were blocked. I have not installed it back on the bike yet but I am pretty sure it is going to work. Lessons learned....clean the master before taking the cover off and if there is a torque value for the banjo bolts ....tighten it more and use new washers!

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