Stuck master cylinder screws

Day three of ownership...the brake fluid level is low, so picked up some nice fresh fluid from the store. Came home and cleaned off the cover of the master cylinder. Took out the screwdriver, and man-oh-man are those srews ever tight! I'm really worried about stripping the heads, so thought I would ask here if there are any suggestions/tricks for proceeding.

Thanks,

Mark.

 

Make sure you're using a screwdriver that FULLY engages the screw, a lot of phillips are too "sharp" and bottom out before fully engaging--file the tip a bit blunt if necessary. Put the screwdriver in the screw and give it a sharp SMACK before you try to loosen it. Put a few drops of PB Blast! or your favorite penetrant on the screws, wait, repeat. You may end up like most of us, buying one of those nifty screw-extractor sets at Sears...

 

Before resorting to the extractor (which I use on a regular basis) someone posted a neat trick I have used several times including my MC screws.

Use a nail set or a punch . Set a nice divot on the rim of the screw head then strike in the loosen direction. Works great and I was able to reuse the screw until I got down to Ace for replacements.

Wish I could remember who posted the idea to give them credit.

 

If you're going to be working on it you'll need an impact driver. Go to Sears or Harbor freight and get one. Usually that'll get the screws out if they aren't buggered.

On buggered heads I've had good luck with a left handed drill bit.

 

Well, I thought of the impact driver, but they aren't available in my town. I'm going to get one when I can. The screws got stripped, so I got out the extractor. Then both the heads came off and left the bolts stuck in. Then the extractor broke. Then I screamed.

Not a good "wrenching" day...but definitely a wretched day!

Mark.

 

Very useful tools to have when working on these bikes:


Impact Drive:

it24) Aftermarket heavy-duty IMPACT DRIVER SET. This is the tool that saves you incredible amounts of frustrtion, effort, and expense when you have a REALLY stuck fastener. Heavy-duty internal ratchet mechanism stands up to the strongest blows from a hammer, while the tool-grade steel drive tips provide long wear and positive contact. Great for helping to remove frozen carb upper and lower rack bracket screws, stuck engine fasteners, and many other uses. 3/8" drive, comes with a set of 4 short bits: one each of a #2 and #3 phillips, and an 8 and 10mm straight slot bit. Metal storage case included.

HCP9706 Aftermarket heavy-duty IMPACT DRIVER SET, includes a full set of four short bits and a storage case.
$ 14.95


JIS Screwdrivers:

mt1) Almost every screw on these bikes are "JIS" design screws, JIS standing for Japanese Industrial Standards, and both the depth and design on the phillips-head "slot" is different than typical US slots. In a nutshell, JIS screws (which can be easily identified by the small punched single "dot" on the screw head, in between two of the screw slots) have both deeper and "squarer" slots and thus can hold more torque than their rest-of-the-world counterparts. They also require a JIS screwdriver to take full advantage of, and to prevent rounding out the slots as typical phillips-slot screwdrivers will do. The more "rounded" edges of a standard phillips-head screwdriver cannot exert as much torque on the screw head (by design, actually) and will "cam-out" of the slots, taking some of the slot material with it unfortunately!

So it might be a good idea to also invest in a set of quality JIS screwdrivers, trust me, they make a difference (yes, they can be used on standard phillips head screws, too):

HCP5904 JIS Standards SCREWDRIVER SET. Japanese phillips drive screws have sharper corners than regular phillips screwdrivers so they won't turn out under heavy torque. In order to take advantage of this feature, and to avoid stripping out the JIS screw heads by using US-standard phillips screwdrivers, it's a good idea to invest in a set of quality JIS-standard screwdrivers. This set of 4 contains one each of #1, #2, #3, and #4 sized-tip screwdrivers, and this range of sizes will handle everything down to an M2 sized screw (that's tiny, smaller than the size of the petcock faceplate mounting screws) all the way up to screws bigger than anything I've seen used on these bikes. They all feature sturdy plastic handles, chrome plated steel shafts, and come in a handy vinyl storage pouch.
$ 37.95


Individual JIS Screwdrivers:

The #2 and #3 fit the most commonly used size screws on the carbs, gauge clusters, etc.

HCP5900 Aftermarket size #1 JIS Screwdriver, for m2-m4 sized screws.
$ 9.95

HCP5901 Aftermarket size #2 JIS Screwdriver, for m3-m5 sized screws.
$ 11.95

HCP5902 Aftermarket size #3 JIS Screwdriver, for m6-m8 sized screws.
$ 13.95

HCP5903 Aftermarket size #3 JIS Screwdriver, for m8-up sized screws.
$ 16.95

 

Same thing happened to me when I was restoring my 750. Both the Phillips Heads were chewed-up and popped-off when I used the Impact Driver.

No problem!
There's enough stock to drill-out the SOFT screws and run a Tap into the MC Casting to save the Master Cylinder.

After drilling the MC Body and re-tapping the holes ... you have to bring-out the holes in the Cover to the drilled-out size.
Be sure to remove the Rubber Expansion Diaphragm/Gasket from the cover when you drill the two holes in the Master Cylinder.

 

That is a first rate job RickComatic. Happens I was looking at screws along the same line as those.

I got lucky with mine, they were really tight. I just got out my trusty redneck impact driver. (If ya have ta ask, Ya don't need ta know, lol)

When that didn't work I applied a small ,very carefully, amount of heat (doesn't take much for this job) from the top as this metal conducts heat easliy and shazamm came right out.

 

I used a small disk on a whiz wheel to cut a slit for a standard screw driver after I hacked up the philips head pretty bad. Worked good but you will put some nice scratches in the cyclinder.

 

Thanks for all the ideas, everyone. Rick, that may just be the ticket and sure looks slick. What size are the replacement bolts/screws you used and where did you find them?

 

The original are 2mm. If you have to drill and tap you may need to go slightly larger but if you tap it you will know the size

 

I got nice Allen-head replacement screws for the MC cover at the local Ace hardware for 30 cents each. The same screws fit the V45 Magna brake MC and clutch MC as well. A great investment for the next time around.

 

Look, your Bike loves you.
Love it back.

Give it that sparkle that can only be defined by diamonds or stainless.
Forget the diamonds.
Do the Stainless!

Both sides:

http://cgi.ebay.com/ebaymotors/Stainles ... enameZWDVW