Topic: New rubber brake hoses for 650?

[RAFster122s]

They are too short in my opinion. Especially when comparing to original. Bolts need minimum of width of fastener in threaded length in a hole to work with proper specs. The threaded banjo bolts are not high torque fasteners though...

[Jimcg]

I checked again and measured. The threaded part is 10 mm shorter on the new bolts. In total the new bolts have 10 mm of threads and the original ones have 20 mm of threads.

/Jim

[bryanj]

I would use original bolts with new washers and make sure threads dont bottom out before banjos tight

[grcamna2]

I checked again and measured. The threaded part is 10 mm shorter on the new bolts. In total the new bolts have 10 mm of threads and the original ones have 20 mm of threads.

/Jim

I would like to have longer threaded portions similar to your stock bolts/lines;possibly 15mm threaded bolts?

[Jimcg]

Thanks for your advice, guys!

I'll check the non threaded part of the bolts and compare them and also measure the thickness of the banjos to make sure the old bolts won't bottom before they are tightened, with the new washers of course.

/Jim

[Jimcg]

I installed the new brake lines with the new bolts. The new banjos were thinner so the original bolts would bottom before everything had been tightened. Thanks for pointing that out. 👍

With the lines in place I filled the reservoir and set things up to do a gravity bleed at first. Seemed to work fine and next garage session I had planned to do the final bleeding process.

But while I sat and watched gravity do its job I stumbled across another thread here saying never to press brake lever fully against the handle grip since that could cause several problems. Well... I did that, several times too. 😞 Does that automatically mean I ruined the master cylinder, that I will have to disassemble and rebuild it or does it mean it MIGHT have caused a problem, meaning it doesn't have to be so? How do I know and is it of any use to continue the bleeding process now that I know I pressed the lever to far?

/Jim

[bryanj]

Probably OK

[grcamna2]

Keep gravity bleeding it;air bubbles rise to the top and as long as your small bleed hole in the master cyl is open it will bleed through there.I made that mistake at some point by pulling the lever all the way to the hand grip:it caused the master cylinder to stay 'air bound' which wouldn't allow the last little bit of air to escape.

[Kelly E]

My favourite way is to fill it from the bleeder valve with a 60cc horse syringe. It pushes the air up to the master cylinder and out. Sometimes you get a firm lever on the first try. I get the syringes at the feed store for a dollar and use a short piece of clear fuel line.
It's the only way to get a good lever on a couple of the hydraulic clutch bikes.

[scunny]

+1 0n the syringe.

[BomberMann650]

+1 0n the syringe.

+2 - the syringe is so efficient

Can't say if pulling the lever "all the way" during a fill has caused me an issue though.  The fluid flows both ways.

[Jimcg]

The day after I posted last time I tried one more gravity bleed session. Sat and watched for a long time and nothing happened. Went inside and returned after more than one hour and found the reservoir empty...

Filled it up and started over. The morning after nothing more seemed to happen the gravity way so I switched to final bleeding. When no more bubbles came out I thought I was finished but the lever felt as soft as if both bleed nipples were wide open so I guess there still had to be lots of air trapped inside.

I only had an hour before I had to go to work so I was stressed and not very happy with my failures so far, so I thought I'd give the syringe a quick try. The hose I had was a bit to stiff and came loose from the nipple after a while and also didn't fully seal onto the syringe so I noticed I was going to push air bubbles into the system, so I decided to give up for that day.

I had been sitting on my tool box for a long while with my legs folded in a way my 54 year old body isn't capable of but didn't pay attention to that in my brake bleed frustration. When I stood up the back side of my right thigh was in heavy cramp and I couldn't straighten that leg tried to fight the cramp but didn't manage to make it go away. That was Tuesday morning and it wasn't until I woke up today (Thursday) the cramp was fully gone. So today was a great day but working for two days like that has been a struggle.

Since last time with the bike I bought myself a better syringe, better hoses and bleeding stuff so next time my plan is to drain the system first and then fill it again with the syringe from the bottom. I'll also pay close attention to my leg position. 🤪

Further reports will come. Thanks for your advice!

/Jim

[grcamna2]

Jim,I use teflon thread sealing plumbers tape to seal the threads on the bleeder screw:that will help.

[Jimcg]

Jim,I use teflon thread sealing plumbers tape to seal the threads on the bleeder screw:that will help.

Thanks, I'll do that after I drained the system.

/Jim

[Kelly E]

Jim,I use teflon thread sealing plumbers tape to seal the threads on the bleeder screw:that will help.

I've been using red brake assembly grease on the bleeder valve threads. Does the same thing as the teflon tape but it's easier for me than trying to wrap tape on the little bleeder valves.

[Jimcg]

Success, finally! Drained the system today and refilled using syringe at the calipers, then did a final bleed as usual. Lever feels fine now!

As usual, I learned a lot. Many thanks for sharing and helping! 👍👍👍

I read somewhere "Not all people can learn from other people's mistakes - some of us have to be the others". 😄

/Jim

[Phoenix]

On my 750, while using the lever to get the air out, if I squeezed it all the way in, some fluid leaked out near the handle.  FWIW

[BomberMann650]

On my 750, while using the lever to get the air out, if I squeezed it all the way in, some fluid leaked out near the handle.  FWIW

Thats not supposed to happen at all 😅

[Stev-o]

On my 750, while using the lever to get the air out, if I squeezed it all the way in, some fluid leaked out near the handle.  FWIW

That can happen when the lever motion is beyond where it should be. Some guys tape a "spacer" to the grip to prevent it.

[robvangulik]

This may be clearer....