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Main Area => General GS500 Discussion => Topic started by: mike04asu on July 08, 2010, 11:09:41 AM

Title: Allen Screws for Master Cylinders
Post by: mike04asu on July 08, 2010, 11:09:41 AM
Hi all,

I've been a member of the site since the day I got my twin about two years ago... Ive never posted because, well, I've never found a discussion which couldn't answer my many questions (and I've had a lot)!  I guess that speaks for the numerous wise people who DO post.

Ok, so... I've replaced the crap Phillips screws which hold the brake master cylinder covers on at least twice now.  Once again, they're about to strip and I don't want to go thru that glorious process a third time.  I seem to remember someone saying that there's replacement allen head screws for this application but I couldn't find the post (thats a first).

So, does anyone know where to order these screws? I looked in the parts fiche for my '90 but not much of anywhere else

many thanks!

-Mike 
Title: Re: Allen Screws for Master Cylinders
Post by: Homer on July 08, 2010, 11:16:11 AM
Can't remember the size or pitch, but here ya go:
http://www.mcmaster.com/#socket-cap-screws/=7vh3r2 (http://www.mcmaster.com/#socket-cap-screws/=7vh3r2)

Get a few for the float bowls and the diaphragm caps while you're at it (standards, not the beveled heads).
Title: Re: Allen Screws for Master Cylinders
Post by: average on July 08, 2010, 11:32:23 PM
You can get a 2 pack of these from (insert your favorite hardware store here) for like 60 cent a pack( I think that's what I paid; maybe 79..) I bought 4mm x 10mm because when I bought these they only had the standard screws in the 12mm lenght but the 10mm have held up just fine. Just a thought....
Title: Re: Allen Screws for Master Cylinders
Post by: black and silver twin on July 09, 2010, 09:31:48 AM
how are you stripping the brake reservoir screws? they only need to be snug-to-tight not 300lb-ft.
Title: Re: Allen Screws for Master Cylinders
Post by: Homer on July 09, 2010, 09:38:25 AM
Tell that to the factory. 
Plus, they use steel screws in an aluminum alloy, so they electrostatically rust and seize.  Phillips-heads are designed to cam out (strip), anyway. 
Or they might be the Jap style that don't fit Phillips-head drivers. 
Either way, it's not his fault.   
Title: Re: Allen Screws for Master Cylinders
Post by: mike04asu on July 09, 2010, 11:25:33 AM
You said it homer!  After a while those screws just sieze up.  When I first got the bike one was so stuck I had to use an ez-out after snapping the shank.  I've never tightened them beyond "snug" and they don't seem to have the JIS type "dimple" on the head either.

Anywho, thanks for all the good info! I have little trust in my local hardware store's screw selection so I'll likely use the link (which is pretty useful, btw).   
Title: Re: Allen Screws for Master Cylinders
Post by: average on July 10, 2010, 12:09:21 PM
I believe I got them from Lowe's but I bought like 3 packs because I seem to have to replace them like every 4-5 years or so..
Title: Re: Allen Screws for Master Cylinders
Post by: twocool on July 10, 2010, 05:55:50 PM
Quote from: mike04asu on July 09, 2010, 11:25:33 AM
You said it homer!  After a while those screws just sieze up.  When I first got the bike one was so stuck I had to use an ez-out after snapping the shank.  I've never tightened them beyond "snug" and they don't seem to have the JIS type "dimple" on the head either.

Anywho, thanks for all the good info! I have little trust in my local hardware store's screw selection so I'll likely use the link (which is pretty useful, btw).   

These screws are ALWAYS in there too tight...........I work in an airplane shop, we do a lot of work on German Sailplanes.........many use MOTORCYCLE master cylinder for the main wheel brake....Magura Brand as used on Motoguzzi and BMW...........

Most of these cylinders have not been serviced in years. (wheel brakes are not used much in sailplanes except for emercency stopping when landing, so they take forever to wear out or need service) )

...........you can't get the screws out.......

In our shop, we have  a special tool........an "impact screwdriver"....You whack it with a hammer and it turns out the screw.........

The deal is, the hammering makes a lot of down force ofnthe screwdriver bit, so the screw does not strip out its slot......

PS.... allen head "cap screws" may not work, usually master cylinder cap  screws are flat head screws which go into a counter sunk cover.......cap screws are not for counter sunk.......

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