Motorcycles, lets see em.

[Baz]

Originally Posted by mgp steve

If you need to hone anything, I’ve found gluing 400 wet to the appropriate diameter round thing: butt-end of drill, brass rod, even wooden pencil and chucking it in a drill motor to work just fine.

Surprised any oem or aftermarket dealer sells rebuild kits for master cylinders.

Thanks, good info!

https://v4dreams.com/shop-blog.html just rebuilt a clutch slave cylinder and has some procedural info on his site.

Unfortunately, I was unable to get the piston out of mine last night - and also this morning when I tried to "pump" it out with a grease gun. This after a long soak last night and also application of Kroil.

I gave up and ordered a new used one from an eBay seller, so that should arrive next week. Hopefully I can continue the rebuild using that unit.

This brake fluid when it absorbs water can really cause corrosion. It's remarkable - and not in a good way....

[Baz]

Got my used eBay clutch slave cylinder today - sucker is in very good condition! Also a new gasket and some speed bleeders, so am ready to continue with the job.

Question - do you guys use these speed bleeders or not. Thanks!

[Bill Douglas]

Yep, but on the 911. Very good.

[Baz]

Originally Posted by Bill Douglas

Yep, but on the 911. Very good.

OK thanks, Bill.

Dang - I had just bought 4 brand new OEM's for the tub earlier this year.

You just made me have to order 4 more - this time speed bleeders!

I'm working on her brakes right now anyway so all good....and probably even better!

[Bill Douglas]

Yes, my fault.

They really do make life easy.

[red 928]

[Baz]

Was a little concerned about getting the piston out but man that puppy popped right out with just a quick shot from my Ryobi inflator!

Talk about good fortune. To obtain a used slave cylinder in this good a condition - I gotta buy some lottery tickets tomorrow!

It won't even need a rebuild - just a little cleaning up!

[Superman]

Yeah, I'd clean that up real good and finally use something like 0000 steel wool, at least, to try to get that bore smooth. Then I'd (of course) use a new rubber rebuild kit and I'd coat everything with Dow Corning 111 or 112 silicon grease. Especially that square-section o-ring that goes into the groove in the piston and rides against the bore.

You're doing the right things, Baz. Mechanical condition is important for aircraft in the same way it is important for motorcycles.

[Baz]

Originally Posted by Superman

Yeah, I'd clean that up real good and finally use something like 0000 steel wool, at least, to try to get that bore smooth. Then I'd (of course) use a new rubber rebuild kit and I'd coat everything with Dow Corning 111 or 112 silicon grease. Especially that square-section o-ring that goes into the groove in the piston and rides against the bore.

You're doing the right things, Baz. Mechanical condition is important for aircraft in the same way it is important for motorcycles.

Thanks and yeah it's been a real eye opener how nasty brake fluid hydraulics can be when proper PM isn't followed.

The brake fluid that leaked out of this slave was very pretty. That which came out of my bike...not so much.

This fellow does a pretty good job with his tutorials on V4's.....

https://v4dreams.com/shop-blog.html

[Superman]

Brake fluid is hydrophilic which in Greek translates to "water loving." It attracts and absorbs water, and this water causes the corrosion. Brake fluid, without water added, is not corrosive. So yeah, they all recommend bleeding brake systems frequently. At least every two years. Do we really do that? No.

[afterburn 549]

Smaller systems are more prone to H20 problems. (less to contaminate)

[Baz]

Yes thanks guys - I remember very well the discussions we've all had over the years about brake fluid attracting and absorbing water. Especially anyone who has participated in track events. Brake science, technology, and maintenance is always included as a high priority topic.

On the subject of brake fluid, it's funny reading my Clymer manual when they refer to brake fluid as clutch fluid in their "clutch" section. To make matters worse, towards the end is a footnote informing their readers that when they specify hydraulic fluid....they are referring to brake fluid.

They really should just call it brake fluid all the way through, IMHO.

Today was a productive day as I was able to finish the rebuild on both master and slave.

Tomorrow I re-install.

Of note, I replaced the old sight glass which had tuned opaque, replaced the 2 top screws, replaced the internals, lubed everything up, and also replaced the old bleeder valve with a speed bleeder.

For such a relatively easy job - this turned into more than I thought it would. Heck, just the work involved with the circlip alone merits it's own chapter of struggle....lol....

Before:


After:


New top screws!


Lucas Girling Limited red rubber grease!

[Baz]

Look what showed up in FB MP.......wow.....so cool!

1981 Honda motocompo
$7,200

[afterburn 549]

these are rare!

[flatbutt]

At $7200 it seems more than steep but to a collector I suppose it's worth it.

[pavulon]

Convenient, tip-top of the Motocompo market analysis:

https://bringatrailer.com/search/?s=honda+motocompo

[Baz]

Originally Posted by pavulon

Convenient, tip-top of the Motocompo market analysis:

https://bringatrailer.com/search/?s=honda+motocompo

Nice....thanks!!!

[Bill Douglas]

Originally Posted by Baz

Was a little concerned about getting the piston out but man that puppy popped right out with just a quick shot from my Ryobi inflator!

You did better than me when I was working on donor SC's calipers. I had them in the living room of a renovation house and connected up the compressed air. Nothing... nothing... boom. The piston came out alright. Spray pained me with smelly brake fluid and also got the ceiling

[pavulon]

and right on time, the Honda motocompacto



https://www.businessinsider.com/hondas-new-electric-scooter-motocompacto-motocompo-2023-9

[The Synergizer]

Well, this thread is now ruined.