How To Replace the Master Cylinder Sight Glass on a Motorcycle or ATV

[@ThreenaddiesRexMegistus]

Just did these in place and without the need to bleed. Levelled the reservoir, drained to below the window with a veterinary syringe and the rest exactly as you did. The replacements are cheap and the same as the polycarbonate originals that have been there since 2007 - just starting to crack. I did use a tool to hold the clutch lever under pressure, but I’m not convinced this is necessary. 👍🏻

[@jonnythefirsty]

Thanks for this. I did it on the bike (carefully) used a punch to carefully tap out the rings and used vise grip and a brass washer to press the glass back in. Sorted ❤

[@47MasoN47]

Didn't even realize these could be replaced! I'll definitely be doing this on my '93 TRX300

[@stephenpatrick8068]

13 mm socket used to press in it appeared; I bought a pair of 18 mm glass lenses from Rocky Mountain & hope to install while afixed to the handlebars - I have "vice clamps" and will WD-40 the outer rim before installation prior to install. Don't want to crack the 🥂 got to go slow. Thank you so much Rocky Mountain !!

[@mattng5389]

Do not use WD-40 on brake master cylinder parts or any petroleum-based products. Only use DOT4 fluid to lubricate as petrol based products will cause the seals to swell and lead to premature failure. If cleaning, you can use isopropyl alcohol to clean.

[@stephenpatrick8068]

@@mattng5389 I rubbed a microscopic amount of WD-40 simply to lubricate the outer walls of the sight glass before installation. That is not & has not done anything to the brake master cylinder functionality

[@chaunceywright1150]

Thanks so much cuz without you telling me the name of the glass I would never got my back brakes fixed but now I'm riding the Harley Davidson 120th anniversary I'll be able to make it thanks to you thanks again

[@chaunceywright1150]

It's here in Milwaukee Wisconsin

[@starshipman]

Awesome help much appreciated, fixing my Harley

[@nathanguymer2756]

Did you replace your glass with one of these? I need to do my Harley too. Dealerships don’t sell the part over here

[@shannonstiles9838]

Glad I ran across this video 👍🏾

[@ethanh3421]

Sure does beat replacing the whole master cylinder

[@RogerDiotte]

Perfect!

[@nissanlevi9965]

Is it the same process for replacing the REAR master cylinder sight glass ? (a Brembo one)

[@bilboswaggens2975]

I didn't even know this was a thing lol

[@frankiejsmith6398]

Not usually go bad. Unless left out

[@jakelencher817]

How do you get the thing to go in straight, messed up 2 of them cause it wont go in straight

[@sebastiandiluise6097]

Hi, great video! hey... have any experience with a Honda VT700 1986? from what I see the parts manual there is no spare parts or o-ring, seems just glued some way.

[@scratchpenguin1]

o-ring would practically “replace” wtv “glue” is holding it, i have a 85’ 700, did the fix works like a charm

[@knowlzy0791]

no freaking way. I am doing this to the same exact year lmao! What are the odds. Did you come up with anything crazy? I might just 3D print a new one. my resin might stay clear enough to see through. If not, oh well. Mine are completely rotted away and the bike is useless without plugging them!

[@FranciscoGalicia]

Thanks so much. How do I know if is for the one I need? Or all all standard? I need a 1985 Yamaha VMAX. Regards

[@rmatvmc]

This is a standard 18mm sight glass which is the most common size. You will need to measure yours to see if this will fit.

[@FranciscoGalicia]

@@rmatvmc I did and ordered. Thanks. Great video.

[@Luggruff]

Question: I have this type of reservoir on my transalp. Are these specific to specific bikes, or can I completely replace it with a transparent cylinder type?

[@rmatvmc]

Most sight glasses are pretty universal. This one measures 18mm so you can check yours and see if you think this would work.

[@jodylarue2312]

Have you done this with brembo? Do you know if those tusk ones will fit in the brembo master cylinders brembo doesn’t seem to sell one directly

[@rmatvmc]

Haven't done this with Brembo, I think the sight glass is a different size but you can measure to be sure. I don't know of a good option as of now, but if I find something, I'll give you another reply. -Charles

[@RaRaCruz]

Where can I purchase the site glass

[@rmatvmc]

www.rockymountainatvmc.com/parts/tusk-replacement-brake-master-cylinder-sight-glass-p

[@RaRaCruz]

@@rmatvmc thanks so much

[@algamei91100]

I have proplam in my bike Harley fatboy 114 The Dealer of harley in dubai they are seying You must replace all that means i will Go buy new one kit assembly you can not change class what you think?

[@nathanguymer2756]

Did you sort this? Harley in the UK are saying the same thing

[@vegmoto]

Do you absolutely have to take it off the bike? Is there any reason why you couldn’t just do this on the bike? My sight glass popped out on its own and I lost my front brake on a ride.

[@rmatvmc]

It's easier with it off. I'd recommend using a vice but maybe you can get a c-clamp and socket to work. 🤷‍♂-Charles

[@frankiejsmith6398]

Use needles nose vice grips when it still on

[@linkmasters535]

This is what gets me it says sight glass for the brake and clutch master cylinder but they are not glass they are some stupid plastic ones that go bad in the sun or summer tell me why they don’t have real glass ones I bought a pair of them for my friends 1990 Honda Goldwing SE 1500 and with in a couple of months later they crumble into nothing and pieces and they are still going up in price quickly so I paid 8 to 9 bucks for two then I checked on them for his bike again and they are 28 bucks for two of them if they were real glass and are very careful when putting them in they would last a lot longer than cheap plastic ones

[@rmatvmc]

What brand did you use? The Tusk Sight Glass we installed has been in there for a couple of years with no issues. -Charles

[@ClayRepairs]

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