Splitting master cylinder from flid reservoir?

[bubbles]

One of the screws which holds the reservoir cap on the brake master cylinder of my 91 R100GSPD has the head sheared off and as I have drained the fluid to change the brake hose it seemed a good time to replace it.

I have removed the self tapping screw which passes upwards through the master cylinder into the reservoir and Haynes say "the reservoir is then pulled off with a twisting motion as if unscrewing it".

BUT the problem is with the thread of the shared screw still in place up through the reservoir its impossible to twist it. So what I need to know is are there actually any threads or is it just the suction of the sealing O ring holding the two parts together.

I have tried gentle persuasion with a thin blade between the reservoir and master cylinder but don't want to use too much force.

Thanks, any help would be much appreciated.

 

[(RIP) Arkwright]

Just be a bit more brutal with it, it will just be stuck to the paint, wedge it off with a thin blade or a screwdriver, then remove the sheared screw. I did one last week that had been stuck down with bathroom silicon 'cause it was leaking, the master cylinder was full of silicon, you will probably need to replace the 'O' ring though.

 

[bubbles]

Just be a bit more brutal with it, it will just be stuck to the paint, wedge it off with a thin blade or a screwdriver, then remove the sheared screw. I did one last week that had been stuck down with bathroom silicon 'cause it was leaking, the master cylinder was full of silicon, you will probably need to replace the 'O' ring though.

Thanks Arkwright, have just jemmied it off with a couple of Mrs bubbles kitchen knives, don't tell her, WDed the remains of the screw and eased it out held in a vice, job done .
O ring and replacement stainless screws ordered, thanks again.

 

[Kenny]

Blimey, just in the process of taking a few pics and already answered

 

[bubbles]

Thanks Kenny, its the thought that counts, .