Reunited with XS650SH

[gggGary]

The seal at the end of the spring?
Still have the original?
I've compared the seal I removed to one from a kit a few times and put the original back in...

 

[Its been a long time]

That's what I've always done. It failed me this time.

Ah. Indeed, you need plan B then.

 

[jetmechmarty]

The seal at the end of the spring?
Still have the original?
I've compared the seal I removed to one from a kit a few times and put the original back in...

This is a master cylinder purchased on eBay. It's good but the internals were roached. It's a Yamaha branded part recommended by @5twins. I believe it came off a dirt bike. It has 11 mm bore. I'm excited about the swap.

 

[gggGary]

I'm excited about the swap.

I would be too. That swap is my go to on all late model XS650's

 

[jetmechmarty]

This brake swap is annoying the snot out of me! I pumped 4 oz of fluid through it. It still won't push the puck. The 2nd kit went in nicely with just a bit of red rubber grease. I've walked away until tomorrow.

 

[Jim]

I did not put the seal in backwards, but it was destroyed upon installation. I'll have to get another kit and try this again. Is RED RUBBER GREASE a preferred or acceptable assembly lube?

Yep.

 

[Its been a long time]

This brake swap is annoying the snot out of me! I pumped 4 oz of fluid through it. It still won't push the puck. The 2nd kit went in nicely with just a bit of red rubber grease. I've walked away until tomorrow.

Apologies in advance for the long story.

I once had a brake bleeding issue that in the end I couldn't fix. A single piston floating caliper similar to XS650 with an 11mm master cylinder. I fitted new piston and rubber seals to the caliper, used a new master cylinder, brake line and banjos. Effectively a very simple new front brake system. I spent maybe 7 hours a day for three days and over a litre of brake fluid trying to bleed it. In the end I gave up and got another caliper. What was happening is that I reverse bled the system to fill it, then used a vacuum bleeder to remove bubbles. But when I pulled the master cylinder lever in, the caliper piston would move out a fraction. When I let the brake lever go, the caliper piston was pulled back in by the rubber seal. The lever never felt better than mushy. So..... I never managed to get to a condition where the caliper piston moved enough to overcome the dragging back of the rubber seal. The caliper sits on the bench to this day. I really have no idea why it did what it did as everything is mechanically perfect with it. Hydraulically, it's as if the 11mm master cylinder wasn't pushing enough volume of fluid to actually move the caliper piston enough to overcome the seal dragging it back. At each pull of the lever the caliper piston could be seen to advance a bit then withdraw as the rubber seal pulled it back.

Sounds familiar?

 

[jetmechmarty]

Apologies in advance for the long story.

I once had a brake bleeding issue that in the end I couldn't fix. A single piston floating caliper similar to XS650 with an 11mm master cylinder. I fitted new piston and rubber seals to the caliper, used a new master cylinder, brake line and banjos. Effectively a very simple new front brake system. I spent maybe 7 hours a day for three days and over a litre of brake fluid trying to bleed it. In the end I gave up and got another caliper. What was happening is that I reverse bled the system to fill it, then used a vacuum bleeder to remove bubbles. But when I pulled the master cylinder lever in, the caliper piston would move out a fraction. When I let the brake lever go, the caliper piston was pulled back in by the rubber seal. The lever never felt better than mushy. So..... I never managed to get to a condition where the caliper piston moved enough to overcome the dragging back of the rubber seal. The caliper sits on the bench to this day. I really have no idea why it did what it did as everything is mechanically perfect with it. Hydraulically, it's as if the 11mm master cylinder wasn't pushing enough volume of fluid to actually move the caliper piston enough to overcome the seal dragging it back. At each pull of the lever the caliper piston could be seen to advance a bit then withdraw as the rubber seal pulled it back.

Sounds familiar?

I dunno. The brake was working fine with the stock master cylinder. I don’t remember what I did with it 17 years ago, but it has stainless lines from MikesXS on it.

 

[Its been a long time]

I dunno. The brake was working fine with the stock master cylinder. I don’t remember what I did with it 17 years ago, but it has stainless lines from MikesXS on it.

You have a different issue then. Just thought I'd mention in the off chance.

 

[jetmechmarty]

That only took me weeks! The 11 mm brake master cylinder works fine. Two issues. One I was trying to bleed it while multitasking. I kept draining the bowl dry. Second, I had the handle bolt against the nut. It was never going to squeeze the caliper. I had to move the bolt all the way in and move the lock nut to the other side. Much better! It stops. It feels quite strange. My stable all has wooden brake. The G handle moves because the rubber lines are original.

 

[5twins]

Yes, it does feel strange at first and takes a little time to get used to, but once you do, I think you'll like it. The biggest thing for me was the increased lever travel, but now that I'm used to that, I really like it. The better "feel" and modulation is wonderful. I put a 1/2" MC on my '83 because I thought it might give less lever travel but still give better "feel". It does give less lever travel but very little improvement in "feel", so I'm going to change it to an 11mm one as well.

 

[jetmechmarty]

Yes, it does feel strange at first and takes a little time to get used to, but once you do, I think you'll like it. The biggest thing for me was the increased lever travel, but now that I'm used to that, I really like it. The better "feel" and modulation is wonderful. I put a 1/2" MC on my '83 because I thought it might give less lever travel but still give better "feel". It does give less lever travel but very little improvement in "feel", so I'm going to change it to an 11mm one as well.

Maybe I’ll put the 14 mm master cylinder on my XS1100. The larger reservoir will swap and the appearance will be as original.

Thanks for the tip on the upgrade.

 

[jetmechmarty]

The 11 mm master cylinder appears to have cured my squealing brake. That's a nice bonus.

 

[jetmechmarty]

I’ve decided this one is taking me to Wisconsin. It has over 14,000 miles on it already. It must be my favorite.

I have/had an oil leak. The countershaft nut was less than finger tight. I set it to 94 ft lbs. and secured the lock.
I found the brushes at the wear bar. I found some better ones in my stash and installed them. I bought six more OE brushes on eBay.
That’s all for today.

 

[jetmechmarty]

It’s getting all cleaned up from the failed trip to Wisconsin.

 

[jetmechmarty]

It’s all pretty.

 

[Jim]

Took me a second....

 

[jetmechmarty]

 

[gggGary]

Hey looking a bit cold there, Missippi!

 

[jetmechmarty]

Hey looking a bit cold there, Missippi!

Mid sixties IS cold in Mississippi!

The Special gets some love at this event.