Front Brake is out

[Anonymous]

My front brake on my '80 gs 450l is out, could someone help me.
this is obviously limiting my learning to ride.

there is no resistance on the lever at all, not even spring tension. i pulled the brake line from the master cylender, there was fluid to the line, and there is spring tension to a small piston (pushed with a small punch) that only moved 1/4" to 1/2". there is fluid in the reservoir. does anyone know how i go about breaking down the master cylender or what my best method of attack to this problem is? going to contact the local kawasaki/suzuki dealer when they open this morning, although i don't hold much hope, they're not much good around here. other help would me much appreciated.

Thanks.
Byron

 

[Anonymous]

Try a simple bleeding of the line before you rebuild

Try a simple bleeding of the line before you rebuild

Oki,
The problem could just be coming from having a little air in the line. Try bleeding the brake first and see how you make out from there. Just make sure that while you are doing so that you don't pull the brake lever all the way in. This can sometimes dislodge the piston in the master cylinder, but then again rarely at that.

Good luck,
Dave

 

[Anonymous]

Check vert closely around the master cylinder and thne caliper for signs of leaks. If non are apparent, remove the brake hose from the master cylinder and pump the lever. Does fluid pump out ? If yes, replace the hose and then remove it from the caliper end. Pump the lever. Does fluid come out ? If so, re-connect to the caliper then bleed the system. When you start to get pressure on the lever but can't seem to bleed it any more, remove the cover from the master cylinder, pull back the brake lever as far as you can the tie it back. Leave it like this over night. Next day, slowly release the lever, pump a few times and tie it back again. All air in the system will eventually bleed.

If you don't see fluid at any of the stages then you have isolated your problem. There arn't many parts to the braking system so it shouldn't be too hard to find. If it is your master cylinder you could repair it but I would be tempted just to pay a visit to your local breakers yard.

 

[Anonymous]

trying with no luck

trying with no luck

there is no pressure or fluid flow or pumping when the line is removed from the master cyl. i haven't yet figured out how to disassemble the master cyl. to check inside there. i've checked the suzuki dealer here local, $45 for rebuild kit. working on checking for the master cyl at salvage yards without having to order it from far off.

Any advice on how to break the cyl down? or if it would be worthwhile?
I've checked the caliper and the line, they both *seem* to be a-ok, but without pressure from up above, i can't be sure.

Thanks.
Byron

 

[Anonymous]

To be honest I've never stripped down a master cylinder. You don't have to get an exact match, just get one that fits your bars, the banjo fitting should be standard.

 

[Anonymous]

banjo fitting?? ................*confuzzled look of someone who just woke up*

 

[moto_dan]

Re: Front Brake is out

My front brake on my '80 gs 450l is out, could someone help me.
this is obviously limiting my learning to ride.

there is no resistance on the lever at all, not even spring tension. i pulled the brake line from the master cylender, there was fluid to the line, and there is spring tension to a small piston (pushed with a small punch) that only moved 1/4" to 1/2". there is fluid in the reservoir. does anyone know how i go about breaking down the master cylender or what my best method of attack to this problem is? going to contact the local kawasaki/suzuki dealer when they open this morning, although i don't hold much hope, they're not much good around here. other help would me much appreciated.
Thanks.
Byron

Follow the following url for a schematic of a Master cylinder(the schematic for your bike is not clear) Removing the screw in the reservoir (#3 on the schematic) will allow the removal of the piston in the master cylinder and allow thorough cleaning. Check o-rings(if bad replace), piston bore for pitting, and general condition. Throughly clean MC, and all brake cylinder parts with brake cleaner only. Reassemble, using clean brake fluid on all the parts for assembly lube. http://bikebandit.com/partsbandit/showschematic.asp?dept_id=130734

 

[Anonymous]

well, after alot of pumping and a wierd twist of luck in trying to check if it was pumping pressure, the master cyl started pumping pressure. so after the same little trick the dang thing works!!! woo hoo.......i have front brakes.

thanks everyone for helping me.


trick was using a finger to keep it from sucking air back, starting with the brakeline off at the MC and then the line off at the caliper, then regular bleeding

 

[earlfor]

For the front brake, with the brake line installed and the reservoir
full of brake fluid, I usually loosen the bleeder valve on the caliper, turn it down finger tight, put a length of tubing over the end of the bleeder valve and then open the valve (turn it about 1/2 turn), squeeze the brake lever all the way down and hold it down. While holding the lever down, tighten the bleeder valve. When bleeder valve is tight, release lever, pump lever a couple times, then pull lever, and while pulling on lever, open bleeder valve a half turn.
Hold lever down when it goes down, retighten bleeder valve. this will pump fluid through the blastic tubing you put over the bleeder valve. Keep doing this until you dont see any more air bubbles coming out in the fluid youre pumping through the system. Be sure to keep an eye on the reservoir so as to keep it filled as you go through this process. (otherwise, you will have to do the whole process over )

Earl

well, after alot of pumping and a wierd twist of luck in trying to check if it was pumping pressure, the master cyl started pumping pressure. so after the same little trick the dang thing works!!! woo hoo.......i have front brakes.

thanks everyone for helping me.


trick was using a finger to keep it from sucking air back, starting with the brakeline off at the MC and then the line off at the caliper, then regular bleeding