Can anyone tell me why there are two compartments in the brake resevoir on my 91 cherokee? Is the large one just for the front brakes? And does this mean i only have to bleed the fronts? Any help appreciated.

 

The larger one if the front and smaller the rear. It's more a safety feature in case you spring a leak to keep from loosing all your fluid.

It's still a good idea that when you bleed your brakes you bleed all 4 wheels any how..

 

The larger front reservoir is for your front disc brakes which require more fluid than your rear drum brakes. The disc brake has a larger piston and bore. There are two separate reservoirs as a safety feature. If you spring a leak in the front or back, you will still have full pressure and use of the brakes opposite end where the leak is.

 

They were designed to prevent full brake failure if you pop a flex hose or let the pads wear so far that the caliper piston ejects itself.