My new bike, mild mod, first I have to get it running right

[jpanichella]

Okay, I'll go ahead and clean up the caliper. Took some better pics of the seat. The vendor was nice enough to give me a discount for the tear, so I'm going to keep the seat.

Here's some better pictures of the seat.

 

[jpanichella]

One step forward, two steps back.

I went to go bleed the system and remove the caliper tonight, and found that the master cylinder is still leaking. It's definitely leaking between the plastic reservoir and the metal piece. I cleaned the mating surface very thoroughly, so I have to assume it's that darn o-ring. Does anybody have a lead on where I can find that part? It's not even in the parts fiche. I can see if any of the little hardware stores have a bin of o-rings I can sort through.

I also seem to have a leak coming from what I believe to be the tach drive.

The connection seems sloppy. I'll see if I can identify if the leak is coming from the sleeve or where the sleeve enters the case.

I'm going to tackle the caliper tomorrow after work.

 

[TwoManyXS1Bs]

That's the clutch cable. If it was pressure-lubed at the handlebar, some lube can ooze out onto that case cover. Nothing no worry over...

 

[jpanichella]

Good to know! I'll just keep an eye on it. In the meantime, anybody have the spec of the o-ring between the reservoir and the master cylinder body? I was going to place an order with mcmaster at work, and was going to use my calipers to make an educated guess with the size. Regular old Buna will work, I assume.

edit:

Did my research, have to use aflas o-rings for brake fluid applications.

 

[jpanichella]

Tore apart the caliper today. Pretty gross inside. I'll have to spend some time with a pick cleaning out the grooves. Does this piston still look acceptable to use? I still need to finish cleaning it up. Has a fair amount of rust on the hollow portion, but I don't think that matters. The seals all look fine, but what do I know. I can't get my master cylinder to stop leaking.

Back to the master cylinder, I was going to order a set of aflas o-rings from McMaster. The best measurement I could get was about 1.83" outside diameter, with a thickness of about 0.13"

The closest I can get with Mcmaster is 1.887" OD with a thickness of 0.139", but I'll re-measure tomorrow before ordering just to make sure

I also got my badges lasercut. They looked good until I messed them up when using solvent to put them together. I attempted to etch an outline of the letters using the laser to catch the solvent and hold it, but it still managed to get everywhere. I'm going to try to etch deeper to give a pocket for the letters to set it. I wanted to give these ones a look to see how they fit.

Thanks again everybody!

 

[TwoManyXS1Bs]

I like those badges!!!

 

[gggGary]

Kinda hard to tell on the piston, give it a buff see how many pits you have, they sell for about 30.00. Because I do this quite a bit, I keep a couple on the shelf so I am less tempted to reuse one I shouldn't. On a different site there is a thread about using silver solder to repair pits in fork leg chrome, I messed around trying it on a dead piston but haven't had any success yet. Apparently silver solder repair is practiced frequently on hydraulic rams with high success.

I thought Jesus was the mischievous badger on this board, but it looks like you are now, good work, keep the pictures coming?

 

[jpanichella]

Thanks!

I'm going to clean up the piston as best as I can and take some better pictures. For the master cylinder I am considering using permatex no. 2 instead of getting a new o-ring. Any idea how well it resists brake fluid?

 

[gggGary]

Nnnnnnnnnnnoooooooooooooo.
No permatex!!!!
I'd go buy a flea bay chinese MC first.

I think I would try the Mcmaster carr oring. heck a get a few I'll try one see how it works.

 

[jpanichella]

Okay, no permatex. Is the main seal occurring at the o-ring? I'm just concerned by the scoring on the top machined surface of the master cylinder, but if there is no sealing there I'll go ahead and try grabbing an o-ring.

 

[gggGary]

Yes at the oring the flat surface doesn't affect the sealing. The inside of the bore where the ring sits is critical. maybe carefully and evenly work that with fine sand paper, like 1000 grit fine, no coarser than 600 grit avoid working any one area. Did you use some brake fluid as a lube when you installed it? That is needed. The one I did recently really was tight, both coming off and going back on.

 

[jpanichella]

I did use brake lube when I installed it. The o-ring itself doesn't look like it's in bad shape, but is kind of "squared-off" from years of being compressed. It was a pain to pop out but putting it back in wasn't really too difficult. I'm going to go ahead and order some new o-rings via mcmaster. If that doesn't do the trick I found some 12.7mm chinese master cylinders on the bay that come powdercoated.

I was careful to scrape all the crud out before putting it back together. I'll double check and make sure I didn't leave anything behind, but at this point I'm fairly sure it has to be that o-ring

 

[gggGary]

A 12.7mm MC would be a nice improvement in brake feel with a stainless steel line.

 

[jpanichella]

The o-rings are 15 bucks for a pack of 6...ugh. That's a lot of money to spend on a part I'm not sure will work. Might just get myself a new master, unless somebody has any other ideas.

 

[gggGary]

Do you have the universal number for the mc o-ring? I have an order going in to a "more reasonable" supplier.

 

[jpanichella]

The AS568A Dash No. for the one I was eyeing up is 223.

Specs are:
ID: 1.609"
OD: 1.887"
Thickness - 0.139

Using my calipers, the groove around the base of the reservoir is 1.55"

When I put the o-ring on the reservoir, the OD is around 1.83"

Let me know if you find anything closer.

 

[jpanichella]

http://www.theoringstore.com/index.php?main_page=index&cPath=367_355_358&sort=4a&page=2

Found some aflas o-rings sold individually. 3 dollars a piece, much better than buying a pack of 6.

edit: direct link

http://www.theoringstore.com/index.php?main_page=product_info&cPath=367_355_358&products_id=11653

 

[jpanichella]

http://www.efunda.com/designstandards/oring/oring_chemical.cfm?SC=Brake Fluid

There's a great resource for determining what kind of o-ring to get in terms of resistance to brake fluid.

 

[jpanichella]

I ordered 2 different sized o-rings from the o-ring store. We'll see which one works best.

 

[jpanichella]

Did some more work on my caliper piston. I took off all the surface rust and what remains is pitting.

The pitting starts about .75" from the top (according to my calipers). Is it still usable? Also, the cylinder that the piston fits into looks okay. There is one visible scratch, but I can't feel it when I run my finger across it.