superbeater

I put 954 calipers on my Hawk with a'09 CBR600RR Radial M/C. They work great. So great I decided to put them on my '06 Vstrom. 954 calipers and a CBR1000RR radial M/C. Work great on the Vstrom too.
The issue I am having is I keep needing to bleed the M/C to keep the lever feel firm on the Vstrom. Perhaps air is working it's way out of the system still but I get great lever and then a few days later, not so much. I'm not riding daily. More like weekly. I did not overhaul the parts like I did when setting up the Hawk. I have SS lines and I did remove the pistons and thoroughly clean them. I checked and tightened all the connections.
Any ideas brake gurus?

IT_Mike

Have you tried back-bleeding them?

My other toy is fickle, and it's reservoir doesn't hold enough fluid to bleed the whole system, so we back-bleed it. Not with vacuum, but with an oil can, fluid, and a section of tubing. Hook the tubing to the bleeder valve and feed brake fluid into the lines from the caliper back up to the reservoir. Watch your levels in the reservoir or you'll have a mess to clean up when it overflows.

Wolverine

Have you tried reverse bleeding? It's worked well for me, maybe give it a try.
Tried to start this at 9:14 to get past a long explanation. This method, like I said, has worked well for me in getting more air out of the master banjo area than vacuum. Best thing IMO is to have the passage to the res the highest spot and let it sit for about 1/2 hour then vigorously cycle the lever to get the air up in the cup.
Not that air is your issue, just trying to help.

8541Hawk

Does it happen after you ride the bike or does it happen if the bike just sits for a few days?

superbeater

1. I did not back bleed these brakes but I have done it before and have the equipment. I'll give that a try.
2. It happens after sitting for several days to a week. Not while riding.
The you think it's just air or do I have a mechanical issue? I'm tending to think it's just air. Persistent
Thanks for the responses.

8541Hawk

Since it does it while just sitting, then you haven't removed all the air from the system.

Try bleeding the banjo bolt at the master cyl.

mikstr

try tie-wrapping the lever overnight...

superbeater

I keep bleeding at the M/C. The CBR1000RR radial M/C has a bleeder. Been about 10 days now since I've ridden the bike. The lever was a little soft. A little bleed and back to nice and firm.

superbeater

I did that right after the install. Re-tied several times overnight.

I guess I'm wondering if there is any way for air to get in? I can keep bleeding until all the air works out. Before this swap, I put my VTR calipers on the Strom with the stock M/C. Easiest install ever. Just pumping the lever gently and watch the bubbles pop up in the reservoir. Never needed another bleed.

The 954's feel great on the Strom and ever better on the 'Hawk.

Wolverine

Are you using fluid that is old or could have been in a container that isn't properly sealing shut, allowing the absorption of moisture?
@ this point I'd say buy a new bottle of good fluid and try a fresh flush. Ya know... summers eve that SOB. LOL!

superbeater

Yeah, that may be the next thing. The fluid was bought in August 2016. Been using it since then. 80% used now. I appreciate all the responses. Was kinda hoping someone would say "Oh, check the blah blah, blah blah" and that would be the solution.

fabiostar

is the bango bolt at the mc the correct one? i had the same issue and it turns out the the bango was a few mm to long, changed it for the right one and the problems away.

superbeater

Interesting. I'll check. The banjo bolt was supplied by Galfer as part of the SS line kit.

fabiostar

its worth a try. the one i changed was only about 2mm shorter but it cured it. its better a tad to short than to long.

VTR1000F

That's what my wife always tells me, but it doesn't make me feel any better.