sight glass replacement

[taz001]

Well here's a PO redneck engineering feat for ya:doh::

http://i178.photobucket.com/albums/w255/tazman001/rearbrakecyl01_zpsd36e1397.jpg

Penny over the sight glass. Leaks(as one could imagne) like a submarine with screen doors:lmao:. Anybody done this repair yet? What'd you do? Post it up.

[Admin]

lmao Uh yea, that's not gonna work too good. :lmao:

That's a first for me.

[prodigit]

So maybe after that, you can drill a hole in the penny, and make a looking glass in that?

LOL!

[spandi]

Use these instead.
http://www.newrivercyclesalvage.com/sight-glass.html
http://www.esslinger.com/mineral-glass-watch-crystal.aspx
http://www.ofrei.com/page_176.html

[MEAN_MOTOFINO]

Yors turly
Mean Machine

[taz001]

thanks Spandi, I'll try them. The last link has glass in .1 mm diameter increments. The other side is cracked and crazed real bad, so I know I'll have to replace it soon also.:thanks:

[spandi]

thanks Spandi, I'll try them. The last link has glass in .1 mm diameter increments. The other side is cracked and crazed real bad, so I know I'll have to replace it soon also.:thanks:You are quite welcome. Glad I could be of assistance taz001! :yay:

(with careful measurements you should get a perfect fit.)

[taz001]

Well I measured the hole where the sight glass was after cleaning up the grey mess under the penny. The diameter was 15.8mm, a size not found on the website(s) referenced by Spandi. So I used a search engine to find this company (http://twincitysupply.net/product.php?productid=18203) who had the correct size. Got it on order and gonna install it with some epoxy.

[spandi]

Excellent work! (I have a suspicion that the lens size you have, might be standard on a lot of motor bikes.) Thanks or sharing!

[jeepsteve92xj]

I've have done one but still need to do the second
I did get mine from
http://www.esslinger.com/mineral-glass-watch-crystal.aspx
I think I used some black RTV after I cleaned the port really well, clean and dry with no brake fluid residue.
Watch Crystal Flat Round Standard Mineral Glass Crystal, 1 mm Thick
MM Size: 16.1mm

The original sight was so fogged and crazed, and I touched it, and it disintegrated.

the one that still needs to be done:
http://i235.photobucket.com/albums/ee107/jeepsteve92xj/scooter/Xingyue/xDSCF0100.jpg


the one I have done:
http://i235.photobucket.com/albums/ee107/jeepsteve92xj/scooter/Xingyue/xDSCF0101.jpg

Steve

[taz001]

the hole for the sight glass seems to be smaller the deeper you get into the master cyclinder. Up towards the outside of the MC it was 16.1 but as I got further down towards the rubber seal it got smaller, hence the 15.8mm size.

[jeepsteve92xj]

I picked out all the plastic, including the original black plastic bushing that was holding the original glass. I didn't think it would make a good enough surface to glue the glass to.
The new sight is recessed a bit but a fine fit. I measured at the front and ordered the glass. I bought 4, plus a couple other items so I didn't feel bad about the shipping cost.

[jct842]

It's probably a late call but have you checked to see any of the glues you plan to use are infact compatible with brake fluid? I guess you know what happens if you get a brake fluid dribble on some paint and leave it there over night. It would not be a good thing to have that glue break down 2 weeks later and melt into the brake system and have to clean out the lines and calipers.

[taz001]

My little test. Mixed up some more of the epoxy I used to set the sight glass with. Then immersed it in brake fluid for two days. Still seems solid.

[spandi]

My little test. Mixed up some more of the epoxy I used to set the sight glass with. Then immersed it in brake fluid for two days. Still seems solid.
Glad it all seems to have worked out. For the benefit of anyone reading, what kind of epoxy was it? (Type, Brand etc.)

[taz001]

Spoke too soon. Left the epoxy in the brake fluid for the rest of the week, and the epoxy started to turn to a clear glop floating in the brake fluid. Looks like I'll have to soak the master cylinders in brake fluid to loosen up the epoxy and start over again. With a different epoxy this time. Any suggestions on type/brand? Something someone has used before?

[jct842]

I think most epoxies are pretty much the same type of thing. If it was me I would bite the bullet and get a new set of masters so I could ride. One thing that could be done is to make a metal plug to cover the hole left by the sight glass and just check it once in a while. But for all the trouble it would take I would still buy new masters. I think they are made of some sort of pot metal or real cheap aluminum castings so solder or welding would be out. john

[taz001]

Well here's the deal-e-o guys. When I started this little project, I epoxied in the sight glass. Then got sidetracked. I came back to the master cylinders a couple of weeks later and read JCT's post about compatibility of the glues. I decided to do a test on the epoxy I was using to seal up the sight glass. So I mixed up some and let it set 24 hours per the label to cure. Then I started my compatibility test. Immersed the cured epoxy in brake fluid and let it sit. Well in 3 days the epoxy was a gel sitting in the bottom of the brake fluid. So I figured that epoxy wasn't going to work. Best way to remove said epoxy? Soak in brake fluid! So I put the M/C (and another sight glass I stuck together from a motorcycle I'm working on) in a container of brake fluid. Well after about 2 weeks of soaking, no change in epoxy. Didn't even soften up. The difference was the cure time. So after 3+ weeks of cure time the epoxy is good to go on the sight glass. 24 hrs, no good, 3+ weeks, good. So if anybody is going to use the epoxy listed here, better let is sit and cure more than 24 hours. I used Permatex 5-minute Permapoxy.

JCT: As for getting M/C(s) for riding, it was too cold anyways. I still gotta finish the engine and fuel system first.

[DW]

Perhaps a large faucet valve washer between 2 steel washers with a screw and nylock nut to hold it all together. Geez, sounds like something I would try lol

[jmstar09]

I have had to fix at least ten of those over the years and what I do is to pick out all the old plastic "Glass" and then clean the entire window with brake cleaner to remove any trace of brake fluid in the window then I fill the entire window with RTV silicone. Black, Red, Clear, whatever. Then I use a matchbook cover or a putty knife to smooth off the surface in all four axis. N,S, E, W so the window gets sealed well all the way around. A little will ooze through the holes in the metal plate toward the inside of the reservoir. You can smooth it out with a pinky finger or just leave it. I leave it. Then allow the silicone to dry for 24 hours, refill and bleed and you are done. If you want to check the fluid you have to open the reservoir cap.

I suppose you could use RTV to glue a new sight glass in place. The RTV will stand up to brake fluid but it's not easy to keep the job neat.

I've also had a bunch off scooters in the shop that had sight glass that was getting ready to leak/fail due to sun exposure. I smeared a nice coat of RTV over the top of the existing glass.