GS1100G Cafe Racer

[pete]

Yeah that's my problem too... but having said that, it may be worth while in the long run as you could use it for car brakes and other bikes as well...

[Hoosier Daddy]

...One line comes out of the master cylinder, and goes to a T junction where it splits into 2 lines, one for each brake.

I double checked the bleeding and there are air bubbles in the system...
On my R6, I pull the lever in about 5mm and it grips hard...

There is no bleeder on the master cylinder so I can only bleed from the brakes. Any help is appreciated.

Did you bench bleed the master before you put it on? If you are carefule not to spit fluid anywhere you can bleed it on the bike by cracking the line open at the master and bleed it that way, then once you get clear fluid there, move downstream to the splitter and do the same at the banjo bolt for the two lines. Then chase it down to the calipers.
Systems with splitters can be tough to bleed, acts like an air pocket that is higher than the bleeder. Try putting the bike on the side stand and turn the wheel to the left. This raises the master cylinder to the highest point. Then apply the front brake and tie the brake lever back with a zip-tie. Leave it set that way over night. The next day, take the zip-tie off and slowly release the brakes and apply a few more times... Should help.
There is a tiny orfice in a master cylinder to bleed back pressure once the lever is released and you will probably see small bubbles in the resivour when you release it that first time.

[oohsam]

Thanks for the reply! I never tried bleeding the T Junction...Wasn't sure that I should have

How do I bench bleed the MC? do you mean by hooking up the brakes and lines while its not on the bike and bleeding it that way first?

I'm considering just taking out the Tpiece, taking off everything of the bike and hooking it up on the bench so the lines are short and trying to bleed it that, then I know if there is an issue with my Tpiece or if I've missed something.
This is driving me nuts.

[Hoosier Daddy]

"Bench Bleeding" is a term for bleeding the new master cylinder before it's installation. You want to make sure you've removed all the air from it and not shoving bubbles down stream. You can do it on the bike now that it is installed. Remove the single line at the "T" (splitter) that comes from the master and bring it up to the master cylinders reservoir. Hold the line down in the fluid and pump the brakes until you get good clear fluid (no bubbles). Some will come out of the hose and some will come out of the tiny holes at the bottom of the reservoir. Keep pumping the lever until it is ALL clear. Now you have a known good source of hydraulic fluid and can re-attach it down to the splitter. Then you can either bleed the splitter by cracking the lines that go to the calipers there, or down at the calipers themselves. You will need to crack the line (or bleeder), apply the brakes, tighten the line (or bleeder), release the brakes. Repeat.
Never release the brake with the line cracked (or bleeder open) or you will suck air back in... and do not let the reservoir run empty, keep topping it off with fluid, or you will get air back into the master and have to start all over.
When bleeding the caliper, I find it easier to take a small hose that fits tightly on the bleeder (1/4" fuel line) and run it down to a small jar partially filled with fluid, that way you can see the bubbles easier and tell when you have good clear fluid.
Some guys think if you do this you don't need to snug the bleeder every time because you will not get air back into the system since the hose is down in fluid. BUT by not tightening the bleeder you are not chasing the air out, you could have a bubble in the line that just moves back and forth about an inch or two. You need to tighten the bleeders to chase it out a little further with every stroke.
It may take quite a while to get this done, think how much fluid the master pushes with each stroke compared to how much fluid is in the system. If the air bubble is at the top you got a loooong way to push it to get to the calipers bleeder.
Hope that helps, Sorry so long winded... I know some of it may seem basic, but I tried not to overlook anything.

[oohsam]

Going outside now to try!

[oohsam]

So i tried bench bleeding the mc. took off the hose attatched to the mc from the splitter and submerged it into the reservoir and started pumping. after 15 mins of constant pukping there were still bubbles coming out of the reservoir. i kept this up for another 15 mins and tiny tiny bubbles were still appearing. i really have a feeling my master cylinder is leaking....does it normally take this long or am i being impatient.

[Hoosier Daddy]

It can take a while... try not to "Jack" the lever too fast, but take it slow and steady strokes. If you pump it really fast you are breaking the air pocket into little bity bubbles and it will take longer to get them all out. Also be sure your hose fitting at the master cyl is tight so it's not letting air back in.
Good news is your getting air out!!! That is exactly what you want to see. Super small "Micro" bubbles are a good sign, you are about done. You can probably re-attach it to the splitter and move on down to the calipers.

[oohsam]

Thanks for the update Hooiser.

I hate doing this. I hate it so much. lol

[GSJohnny]

What are the specs on those tires? They look great... the rear looks like it has more of a taller curve on the tire surface. Am I wrong? Is there any reason why they wouldn't fit on my 80 GS1000G?

Thanks


~GSJohnny

[oohsam]

Hey Johnny boy.
The specs are as follows

130/80-17 (Rear) & 100/90/19 (Front)

They are PIRELLI SCORPION TRAIL DUAL PURPOSE tyres.
The are wicked, and they are also not too expensive. They are designed for touring and a little bit of off road...i think 90% road 10% off if you ever need to go offroad.



On other news. I bench bled the MC as your advice Hoosier, did it slow and steady this time. Got all the bubbles out. Then I hooked it up to the T Piece, then tried to bleed the calipers. Was not getting much joy.

So I hooked up my syringe and started to suck fluid out. Lots and lots of bubbles were coming out. Kept doing this on each side till no more was coming out.
Checked the lever and I have tension there.
Its not heaps, but I cant pull back the lever all the way no, only half way.
I tried to keep bleeding but I couldn't get any more bubbles out.
So I zip tied the brake lever. And am just waiting overnight to see if that relieves any more bubbles... will let you know

I'm very happy to get to this stage! Thanks for the advice. I have a sneaky suspicion I may have got some air in the MC that may need to be bleeded...but i'll wait till tomorrow to see if my zip tie trick worked before I start cracking open the banjo bolt to bleed.
Might also try bleeding the T piece ifI cant bleed anything else..
woohoo..

[Hoosier Daddy]

YEAH! I knew you could. Even still, going here was the fist thing I did after making coffee to see how you did.
Congrats!

[oohsam]

hahah thanks man. Its good to know I gots some love out there
Now i just have to do some fine tuning to get the lever rock solid Thanks so much for ur help man. I been going at it for days and I've finally got something

[pete]

Nice one on the bleeding!

As to those tyres... jealous! I'm having so much trouble finding dual sports for my 450 as it seems noone in Brissie that has an online presence stocks Shinko... and they're the only ones I can find that have suitable 18" front and rear dual sports...

[oohsam]

My good man,
No one in vic stocked them either. I got them from a place in Sydney on Ebay. They shipped them both for $20 (both tyres!). Cost me $250 all up.

Here is the info. I suggest emailing them instead of buying on ebay as they will combine the postage.

Check this link. This is what I got i love ebay.

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=330578489248&ssPageName=ADME:X:RTQ:AU:1123#ht_871wt_907

[salty_monk]

Looking good Sam. Make sure you don't have air being drawn in at the bleed nipples, TomMLC had that problem with some new bleed nipples he fitted. They didn't leak fluid but did let in air.
Think he finally solved it with a different set of bleeders. Maybe speed bleeders.