Front brake master cylinder

[gordon]

hi guys in need of help once again , the two screws that hold the lid on the front brake master cylinder have been rounded of by some one , so whats the safest way of getting them out  ?.


i have a new lid and screws also the right hand pads seem not to be wearing as much as the left side when i changed them last week .


ta guys

[stevierst]

It can be an awkward one this! I've had to drill the heads off them before now, but I've also (carefully) used an impact driver sucessfully on one.  :eek  Try a different shaped screwdriver/bit first, you never know, you might just get lucky........
It all depends on how rounded they are? If you've gone at it with a power screwdriver or completely mauled 'em, then your gonna have to get the drill out.
The key is when you replace them to get a screwdriver that is a 'perfect' fit, and not to tighten them too much, just nip them up.
Good luck!!

[darrsi]

Pads wearing on one side would point at sticking pistons. Did you give the caliper an external clean up when you changed the pads, as in toothbrush and brake cleaner with the pots pushed out a little way, then red rubber greased?

[JZS 600]

Are we at the right end of the front brakes here?  :lol

[limax2]

Drilling the heads of is an easy option. The screws have countersunk heads and if you have a drill with a 90 degree point you can drill the heads off without damaging the cap. Not to be too heavy handed of course. Once the heads are off the cap can be lifted off and the rest of screw can usually be undone by hand. If not there will still be enough of the screw sticking out to grip with pliers.

[darrsi]

"....Are we at the right end of the front brakes here?...."


What d'ya mean? Did ya read what he asked in full?

[Jimmygixxer]

I had the same problem a while back, i used a dremel type tool with a very small grinding wheel attached and made a nice slot for a flat head screwdriver to easily get them out.

[JZS 600]

Ah, the old read the E mail trick!


(just saw the first bit,,,,)

[Jamieg285]

I had this problem with one of the screws on mine.

Easy job - get a 3mm drill bit and carefully drill a small way into the head.  Then use a screw extractor (also know as Easy Outs) and see if it will grip the hole.  If not, just drill a little deeper and try again.  I did mine in 2 minutes.

[darrsi]

I replaced my screws recently, they only need nipping up finger tight, and i put a bit of copper grease on the screw threads just for good measure.

[Dead Eye]

One of mine rounded off to which I drilled the entire screw out and then just hoped that one screw would be enough to hold the lid on - thankfully it was and I didn't have any issues (granted the bike only did 500-1000 miles on this)

[gordon]

hi guys job done with all your help


thanks

[willmckeand]

Hi guys,

I have the same problem, and I need to know what size the screws are and where I can get hold of some new ones?

Thanks!

[fazersharp]

Pads wearing on one side would point at sticking pistons. Did you give the caliper an external clean up when you changed the pads, as in toothbrush and brake cleaner with the pots pushed out a little way, then red rubber greased?

This is tru But gordon you said that you noticed this after a week only ----- must be a micron difference

[Jamieg285]

Hi guys,

I have the same problem, and I need to know what size the screws are and where I can get hold of some new ones?

Thanks!

Pass.  I just took the old one into a bolt/screw supplier and asked for a new one to match.

[His Dudeness]

They're standard metric screws so they'll be sized the same way as the metric bolts. So you measure the diameter at the threaded end to give you the M size. So 4mm diameter is M4, 5mm is M5, 6mm is M6 etc. The next thing you need is the pitch of the screw. Each screw size has two standard pitches fine and coarse. There is a picture to show the difference. The pitch is basically the distance between the threads so a fine pitch means more threads.



The table of standard pitches is there in the "preferred sizes" section. You can see there's two pitch values for each M value
http://en.wikipedia.org/wiki/ISO_metric_screw_thread

So as an example say it measures 4mm at the threaded end so it M4 and by looking at it it looks like a coarse thread so from the table it's pitch would be 0.7 so it M4 x 0.7 and measure the length and it's 20mm and it has a counter sunk head. So it's M4 x 0.7 x 20mm counter sunk screw