master cylider fluid level check windows going bad what can i do

well my master cylinder fluid level view window things have had there time in the sun and are cracked up bad and one is starting to bulg out just wondering if they can be replaced or just pluged up some how talk to my local honda shop they said i need to get the whole mastrer cylinder and when they told me the price i shit my pants right there. so is there any way to fix this or am i stuck with geting replacment master cylinders

 

What bike? Year, exact model, etc. 6 years is a wide range, and there were changes.

There are some pretty smart people (if a little crazy :twitch: ) who post on this board, but I don't think any are clairvoyant - at least not today. :unsure:

 

I used watch Crystals, installed like the factory did.

 

sorry didnt realize i forgot the modle its a 84 vf500f

 

Using the watch crystal glass is a smart idea. Is the 17.9 on the label the diameter in mm? I wonder if the VF500 will be the same diameter? I will have a go at this as my clutch sight glass has crazed over too.

 

Watch crystal works great. Not sure about the 500's but the magna/sabre's use the 16.7 mm lens of either glass or mineral glass. 8mm, I think the thicker the better as they are much thinner than the original plastic. Just measure yours when you remove it.

Taken from another source.

Wash out all the crud from the master cylinder with warm soapy water. Take a small screwdriver and push a hole from the inside out. Do NOT remove the metal slotted piece, only the plastic lens is to be removed. Take small, preferably curved needle nose pliers and grasp the old lens through the hole. Pop it out. Both of mine came out in one piece. I’ve heard that some have had to pick them out bit by bit.

Clean everything really good. If there are any chunks left, use either a match stick or toothpick to remove them. Use caution on the metal surface not to mar it. The final step for cleaning for me was using a bit of lighter fluid on a Q-tip to prepare the surface for the lens. Not the whole master cylinder!

I’ve used both Clear RTV sealant by and Windshield and Glass sealer by Permatex. Both are silicon based and seem to hold up just fine to the brake fluid. The RTV sealant was tested by soaking some in DOT 4 with no breakdown. Scooter likes the black RTV.

Use a straight pin and poke a hole in the nozzle for the sealant. Run the tiniest of beads as possible on the surface around the hole. Rather than my fingers, I used a piece of tape on the end of a pencil to pick up and apply the new lens to the hole. Put the lens in and poke it down. If you have too much sealant, it’s going to squish out and be visible on the inside of the lens. Your standards of perfection may vary.

As a precaution, I ran another bead on the outside of the lens and used my finger to smooth it up. Then with a Q-tip, cleaned the surface of any residue.

Let the whole thing dry for at least 24 hours to ensure proper curing of the sealant and all residual water is dried.

 

I removed the old lens, put a washer in the slot (where the old lens was pinched in) and tapped on the washer to remove the thin band that held the old sight glass in. Then cleaned the o-ring and installed the watch glass and pressed the band back in place. No chance of leaks like when gluing them in. I used the thin glass or the retainer band will stick out too far.

 

I used watch crystals with black RTV over 4 years ago. No leaks. Sometimes you can find site glass replacement kits on ebay. You will pay more, but might be more convenient.

 

Capt, are you saying there is a band or o-ring of some kind holding the stock sight glass in place?

I have an 86 vfr700, do you think it uses the same 17.9 diameter lens as your 87?

 

Yes, the thin band is on the outside and the o-ring is behind the lens. If you break out the plastic lens (remove bits around the edge) you can put a washer in and tap on it to remove the band, so you can reuse it, my o-rings were good, install new lens and press the band back in. Should be the same lens mine used.