Master Cylinder Rubber Inserts

[Boston.Anton]

What do you call the little rubber insert gasket things that go into the brake and clutch master cylinder reservoirs? Where can I buy some? Anyone have any for sale?

Thanks in advance!

 

[Fire-medic]

Master cyl gaskets for the cap.

The fiche says: reservoir diaphragm
Brake side:
36Y-25854-00-00
$13.23
https://www.ronayers.com/oemparts/a/yam/50045c16f8700209bc79430c/front-master-cylinder

Clutch side:
Reservoir Diaphragm
1AE-26454-00-00
$10.11
https://www.ronayers.com/oemparts/a/yam/50045c17f8700209bc79430d/front-master-cylinder-2

Buy six of those tiny screws, you'll have two spares.
Screw, Flat Head
98707-04012-00
$1.66 each
or, buy them from a hardware store

If you've never-removed those screws, they can be difficult to remove. I suggest a #1 phillips in a hand impact driver. Use a flat head punch about the size of the screw head, and rap the screw head several times before you try to use the impact driver. You may luck-out and be able to remove the screw due to the better grip the hand impact driver gives you. If it doesn't unscrew, use the hand impact driver. Pre-load the impact driver in the lefty-loosie direction, in the phillips screw X before you strike it.

 

[KSRider12]

Yeah, I had to drill the brake M/C cover screws out on mine. Big fun...

 

[Fire-medic]

Yeah, I had to drill the brake M/C cover screws out on mine. Big fun...

I usually can remove them if the phillips X gets stripped-out by using a Dremel-type rotary tool to cut a slot in the screw head, and choosing a tight-fitting slot head screwdriver. I don't worry if I nick the sides of the cap a bit with the cutting disc, to form the slot deep-enough to be able to get a good fit. I do think it's important to give the screw a few raps with a hammer and round flat punch, if it doesn't want to come-out.

I've also used a hex-head machine screw instead of a tapered flat-head screw identical to the replacement. It's certainly easier to get a snug torque on the screw if it's a hex-head.

If you can't find the correct length replacement screw, visit the hardware store buy several of whatever longer length they have and a few nuts to fit. Run down two nuts, lock one to the other once you know where to cut, and use your Dremel/rotary tool to cut the screw to length, then re-tap the thread end by removing the nuts. Snug is good-enough installing the reservoir cap.

I've also drilled and tapped the screw hole in the master cylinder body, deeper, to be able to get a good purchase for the cap to be fastened.

 

[Boston.Anton]

Thank you Fire-medic!

 

[Fire-medic]

Sure, you're welcome, when you find a fix from working on your bike, post it up, pics help people to understand, and there's always someone who has a similar issue, sooner or later.

 

[norcalAF]

I swapped out my screws for some stainless hex head ones. The pack I bought was 100 screws, far more than the 4 I needed, if anyone would like a set of 4, send me a pm.

 

[02GF74]

Just be aware that stainless steel and aluminium are not a good mix, as anyone with a series lad rover will tell you.
A better option zinc plated or bla k plated screws.

See here
https://www.albanycountyfasteners.com/blog/stainless-steel-and-aluminum/
... TBH I've done that but applied a dab of grease on the threads.

 

[norcalAF]

Just be aware that stainless steel and aluminium are not a good mix, as anyone with a series lad rover will tell you.
A better option zinc plated or bla k plated screws.

See here
https://www.albanycountyfasteners.com/blog/stainless-steel-and-aluminum/
... TBH I've done that but applied a dab of grease on the threads.

good to know, thanks

 

[02GF74]

... water is the main culprit when I referred Land rover aluminium panels disintegrating.