18 replies to this topic

[andys]

Hi Guys,

Well I am still trying to get my ebay purchase out of the garage........ but I have learnt loads of things about working on trials bikes so not all bad.

Latest problem is that I cant get the front brake to work. I have bleed it using every method I can think if gravity, sryring and pressure. But nothing seems to work still very spongy....


Any ideas?

Cheers

Andy

[scorpa3]

Have you tried pushing the pistons right in, wedging them in place and bleeding them again? There might be air trapped behind the pistons which isn't getting pushed out.

[andys]

scorpa3, on May 3 2007, 12:50 PM, said:

Have you tried pushing the pistons right in, wedging them in place and bleeding them again? There might be air trapped behind the pistons which isn't getting pushed out.

sort of, I pushed them in but did'nt wedge them in place and bleed. I pushed them in then just bleed them I will try your idea......... if that does not work is off to the local dealer!!!! Just want to ride it now...

[copemech]

Never had a problem. Once you bleed air from top of bleeder side, rest should migrate out the hose to the top if you leave the top off the master and continue to pump slowly untill firm. Hope that helps.

[paul_thistle]

Turn the bars so that the master cylinder is uphill from the hose(slightly). With the cover off the resevoir tap the brake lever so as to just move it a little. Watch for air bubbles out of the holes feeding the piston. Tapping the line can also help the air move up and out. This method is subtle but works quickly.
Another method is attach a hose the the caliper bleed screw and run it to a container. With the cap off open the bleeder screw about 1/4 to 1/3 turn. Then smoothly pump in steady strokes and watch the fluid coming out of the (clear) line. Some times you can pump fluid through like this in a steady stream and it will remove the trapped air. When complete hold the lever in and close the bleeder screw qiuckly. This is the method we use to change the fluid.

[KTMSprocket]

Things I do....sometimes one works, sometimes you need to do all.

Reverse flush:: Syringe fluid through caliper and up and out of the reservoir. Messy so use rags.

Bleed:: Attach clear tube to caliper nipple and have it go into a half full clear container of brake fluid. Pull clutch lever in while opening the nipple. Close nipple before you let go of lever. Top up reservoir with fluid as you go. Do this steadily and take your time. PS. You do feel like you need 6ft arms or a blonde assistant .
Bleed the banjo union:: Sometimes you need to loosen the banjo at the reservoir and reverse syringe fluid through the caliper. Messy.

Use harsh language:: Shout at the f*kr and then set light to it.

[scorpa3]

KTMSprocket, on May 4 2007, 07:04 AM, said:

Things I do....sometimes one works, sometimes you need to do all.

Use harsh language:: Shout at the f*kr and then set light to it.

I've never done that to a bike but I lost a computer and a DVD machine in a similar fashion. Not involving fire but an upstairs window and a concrete patio. Beware..... using this method to fix your bike won't work well!

[andys]

Thanks guys............. If I dont get it sorted today I think I will go down the fire route.......

Will try evey method you have come up with before I give up.....

cheers

Andy

[Baldilocks]

Tried this once and it worked

make sure the master cylinder entry point for the hose is the highest point in the hose route you may need to drop the caliper a little, turn your bars to the left as well. Pump the lever till you get some pressure in the system then zip tie the lever to the handlebar so it can t return.

leave it over night

in the morning it should work fine, if it does send a PM to Racey and say thanks as he told me and it worked when i did it.

still dont know why though......

[powellriver315]

i was ready to light myself on fire until my wife suggested; hang fr wheel up from ceiling, rotate mc, and bleed using clear tube method (clean). worked great on my monty but i havn't found a blond assistant to help me lift my goldwing!

[Stoford]

Hi, I usually use the syringe on the bleed nipple technique - however make sure that you back off the adjuster screw on the lever, this allows the piston on the master cylinder to move fully back letting any trapped air out. Leave the master cylinder cover off whilst you're doing this but be careful with the pressure on the syringe otherwise you'll get a shower with hydraulic fluid!

Hopes this helps, Stoford.

[KTMSprocket]

i fink i can smell burning...

[andys]

wheres the F****ing matches ..................... have tried everything now with no luck

[gaz]

just had a problem with my rear brake. Took the swingarm off and back on again. Then come sat night before a trail found there was no back brake. Tried bleeding it for a while and only got some of it back, but only just. At this point I locked the bleed screw off then sheared the screw in the caliper!!!!!! Fortunately it had sealed just sealed in the caliper for me to ride sun.

I did notice that when I assembled the swingarm and master cylinder back to the bike, the master cylinder connection that hold the pipe to the reservior rotated quite freely. I wasnt sure if this was like this in the first place?! I also noticed that when I had "finished" breaking my bike, that air bubbles came up into the reservior as I pumped the pedal. The cap was still off the res at this time.

To finish off my weekednd of destruction I snapped my gear lever on sun, at the very same rock i snapped my brake pedal last weekend!!!!!

Any advice on the brake would be helpful for me and hopefuly might help andy too.

[dale]

I would,nt think the conection should be slack enough to turn, is it leaking any fluid? If fluid can get out - air can get in.Position the hose exit to suit -tighten it up and reverse bleed it.