brake bleeding ... i'm gonna go nuts!

[bikerzx7r1981]

By rubbish you mean they just feel soft..like you dont get a stiff lever till about halfway pulled? Or its soft all the way to the bars?

yeah its feels soft and the the lever will push back to the bars, brakes are on... but not enought to stop at any speed/resistance

[chuck hahn]

OK...Pump them up as hard as you can get them and tie the lever back with a bungee or whatever. Take a flashlight and inspect every inch of the lines and every banjo bolt looking for any wetness at all. if theres none, then leave the bungee in place over night and then come back and pump them up to see if the feel gets stiffer. If it has improved, then pump them up again and repeat the tie back scenario. I am of course assuming youve rebulit the calipers correctly with new seals????

[chuck hahn]

What bike and year is this???

[chuck hahn]

OH...and was this a used Bandit master cylinder? Are you sure the piston and seals in that are ok? Did you rebuild that as well??

[bikerzx7r1981]

when i say ive rebuilt the calipers i just wokred the psitons untill the came out freely, see the bike had been stood sometime.... what seals would need to be replaced? piston seal~?


The bandit master cylinder was second hand, but it seems to be doing its job... pumping plenty of fluid through

sorry the bike is a 1982 gs1000G

[hampshirehog]

I would strip the whole lot down for a clean. Bet there's loads of gunk in there.

[bikerzx7r1981]

I would strip the whole lot down for a clean. Bet there's loads of gunk in there.

Yeah i think that the plan tommrow, if i pop the piston out each calipers, can i reuse the seals?

[chuck hahn]

Parts fiches do not show an 82 1000..either its an 82 1000s or an 1100G..In any case, number 3 is the dust boot and number 2 is the piston seal that fits in the groove in the 3 caliper body. Now that youve stated you didnt rebuild anything this points me to believe you should. Remove the pistons and inspect for any rusting or pitting..they should be absolutely spotless on the OD that rides against the seals. Next remove that old hard seal and clean the groove in the caliper body so its as clean as you can get it..free of all that hard chalky scale youre gonna find. Clean all the hardened brown brake fluid out of the caliper .Install an new seal. Lube the seal and piston with a wipe of brake fluid when you put the piston back in. Here the caliper schematic for the front. I will post the master cylinder and rear brakes in the following post.

http://www.boulevardsuzuki.com/fiche_section_detail.asp?section=96081&category=Motorcycles&make=SUZUKI&year=1982&fveh=2157

[chuck hahn]

Rear caliper...http://www.boulevardsuzuki.com/fiche...1982&fveh=2157
Front master...http://www.boulevardsuzuki.com/fiche...1982&fveh=2157
Rear master...http://www.boulevardsuzuki.com/fiche...1982&fveh=2157

[bikerzx7r1981]

many thanks, and i will do this.

I just wondered though, if th pistons were leaking would i see fluid coming out/ going down in the master cylinder?

[hampshirehog]

Like Chuck says - look at those pistons very closely. Any chips or rust -they're junk. If you get new ones get the stainless ones (they're usually cheaper than OEM) and don't use the rubber boots.

If your seals are hard replace them. If they're soft you can reuse them (they're rip off expensive here - i think the UK ones are made of platinum).

[hampshirehog]

many thanks, and i will do this.

I just wondered though, if th pistons were leaking would i see fluid coming out/ going down in the master cylinder?

The usual leak will show fluid leaking out on the lever (above and / or below so look at both sides). Any damp there at all is suspect.

[chuck hahn]

If you reuse the seals..be sure to clean any stuck on scale from them too..you can use a thumb nail to scrape and clean them up. I think your catching onto the overall theme emphasizing the word CLEAN...A dremel with the wire wheel works well to clean the grooves, or a very small wire wheel mounted in a drill..

[hampshirehog]

If you reuse the seals..be sure to clean any stuck on scale from them too..you can use a thumb nail to scrape and clean them up. I think your catching onto the overall theme emphasizing the word CLEAN...

Did Chuck mention clean? Just in case he didn't......

Chances are the brakes have never been to bits and still contain crap in there from 30 years ago. If you look in the MC you will see a tiny hole and then an even tinier one (my eyes can't see the tinier one anymore). If you have any crap in the system as small as that smaller hole you can end up with a problem. Hence clean.

[Road_Clam]

Well i opted to buy a Bandit master cylinder, hooked it up and instantly better, even when bleeding it I got all the air out.

If you have a lever that pulls to the bars you still have a substantial amount of air in the system. If you have a "semi-firm" lever that pumps several times to a firm feel, you still have a trace amount of air in the lines,