[numb_skull]

Hello sorry if this was already posted but i could not find it.
I am trying to pinch my brake line to see if my master cylinder or brake cylinders are leaking.
BUT the line seems to be hard to pinch off.. can the lines on my bike be pinched off or is there a flexable solid tubing inside that i will damage? Ps i am trying to pinch the flexable line not the obvious solid lines.

Thanks!

2002 450ES foreman.

 

[alloutdoors]

Hello sorry if this was already posted but i could not find it. I am trying to pinch my brake line to see if my master cylinder or brake cylinders are leaking. BUT the line seems to be hard to pinch off.. can the lines on my bike be pinched off or is there a flexable solid tubing inside that i will damage? Ps i am trying to pinch the flexable line not the obvious solid lines. Thanks! 2002 450ES foreman.

I'm not following along on what exactly you are trying to accomplish. Is the unit leaking break fluid and you are attempting to locate the leak?

 

[_Wilson_]

I believe this image shows what the OP is talking about, (pinching the brake line) you want damage the rubber part of the brake line, i would slip some short pieces of rubber line over the ends of the pliers , or wrap them in black tape

 

[numb_skull]

I am trying to pinch the line off after the master cylinder to determine if my air leak is there or somewhere else. But when i go to pinch down on the flex house anywhere it seems like im gonna damage or crimp something off on the inside of the hose. I also wanted to pinch the house off at the wheel cylinders if i had to replace one to save the bleeding nightmare.

 

[fishfiles]

are you trying to pinch too close to the fitting and you are hitting the barb inside the hose , or maybe the hose is full of crude like rust or mud that backed up from a bad wheel cylinder ----I have a 2002 450FM and have done the pinch bleed on it , so would think something is inside that hose

 

[numb_skull]

When you pinched the line. Was it hard? Did you have to use a lot of force or was it soft?

 

[fishfiles]

it was soft , I have pinch pliers , but you can use a small vise grip and a piece of rubber or cardboard to prevent damaging the hose with the teeth of the pliers ----I suspect your hose is full of something ---I have seen rust build up in the hose barb or the banjo fittings and totall clog it up , can you blow air thru it

 

[numb_skull]

Well im trying not to drain the fluid if i dont have to. My brakes are loosing pressure i have to pump the lever to get any pressure then it goes away. So i am trying to pinch the line off after the master cylinder to see if i still loose pressure after i pump them up to see if its my master that needs to be rebuilt or something else like a cylinder. I cant see my line being full of anything i never lost any brake fluid. Just feels hard to pinch off for some reason

 

[Goober]

A thought. You should change brake fluid every two years—the fluid discolored, crystals and a waxy goo can form.

If your mc is still spongy, pry out the fluid seal and jiggle the brake lever—rotate the bars and thump the brake lines to release any air trapped in the upper hoses.

Check this pic I tried for two days to get my brake lines clear. I had air right behind the mc

 

[retro]

...
My brakes are loosing pressure i have to pump the lever to get any pressure then it goes away.
...

This condition is most likely caused by worn/leaking cup seals and/or corrosion damage in the bore of the master cylinder. To fix it you can either replace the master cylinder with OEM, or repair your master cylinder with a high quality rebuild kit. You won't know whether your MC is rebuildable or not until you disassemble it to check for heavy pitting/corrosion in the bore.

 

[Goober]

Yup a rebuild kit cost me $16 and brake fluid $4. Worth it.

 

[fishfiles]

Well im trying not to drain the fluid if i dont have to. My brakes are loosing pressure i have to pump the lever to get any pressure then it goes away. So i am trying to pinch the line off after the master cylinder to see if i still loose pressure after i pump them up to see if its my master that needs to be rebuilt or something else like a cylinder. I cant see my line being full of anything i never lost any brake fluid. Just feels hard to pinch off for some reason

it is all speculation at this point , a brake hose that can't be pinched with pliers has to have something wrong with it ------ crazy things happen , I have seen mud and rusty looking goo , get up the brake hoses any where from 6 inches , to past the splitter tee , and all the way up to the master cylinder , gets in from bad wheel cylinders , when applied fluid leaks out when released dirt and water gets in , then I have seen where there was a clog in the hose from rust in the banjo fitting and there was pressure at the lever but the wheel cylinders never moved , maybe if you bought it used , the PO owner put the wrong stuff in the master and the hose had a reaction to it ------- since you can't pinch it , did you try bleeding it , maybe be air in the lines or out of adjustment or worn out brake shoes -------

 

[numb_skull]

Ok here is exactly what is happening. When i squeeze my front brake lever it goes right to the handle bars. When i pump the lever i get brakes. As long as i have the lever squeezed the pressure stays strong. As soon as i release the lever and go to squeeze again it goes straight back to the handle bars. When i have the lever pumped up and the brakes are on i can squeeze hard for as long as i want and i dont loose any pressure. No
fluid is leaking from anywhere.

All my cylinders are clean and working good. My shoes have lots of pad and i just bled new fluid through the system. Zero air came out when i bled the new fluid through.

 

[_Wilson_]

Only thing i can think of is, the brakes need adjusting .....

 

[Goober]

If it holds pressure after you pump the lever there’s definitely air in the system. I know you’re frustrated same thing happened to me for three days on a three day weekend. Did you pry out that nickel sized seal from the master cylinder like one my pic? Just try it. Both of those holes under the seal have to be clear and the mc has to be clean.
Post a pic of the open mc

 

[fishfiles]

out of adjustment of the brakes or air in the system ----- did you adjust the brakes with the drum installed ?