I've had an issue for a while now, my brake fluid leaking our from what appears to be the seal around the bottom of the brake fluid reservoir. It'* to the point where I have to top it up once a week or so. Looking into it, I noticed that the reservoir is part of the 'brake master cylinder'. Do I need to replace the whole part? Is it possible to reseal the leak, or buy just a replacement reservoir?

Another thing, is it something I can do myself? Or should I just bring it to a mechanic?

Thanks.

They have master cylinder rebuild kits, but they cost almost as much as a good rebuilt one, so considering as cheap as the master cylinders are I'd just buy one and replace it.
It is not too hard of a job if you know how to bleed your brakes, which includes bleeding them in the proper sequence.

Wheel Bleeding Sequence
Rear wheel drive models: if manual bleeding, RR-LR-RF-LF; if pressure bleeding, bleed front brakes together and rear brakes together.
Front wheel drive models: RR-LF-LR-RF

https://www.gmforum.com/mechanical-1...linder-279220/

I always thought (regardless of drive) RR, LR, RF, LF. Always start the furthest away from the master cylinder and work your way in.

That is what I thought as well, but that is the info copied from my AllData manual, I don't have my subscription anymore, but saved all the important stuff as web page files...

1995 OLDSMOBILE 88 Master Cylinder Reservoir