Brake Master Pump
 

I have a 89' 300CE and about to replace the Brake Master Pump. Just preventive maintenance.

Does anybody know if I can swap for a bigger master pump from later models??

Thanks. :)

Do you mean master cylinder? A larger diameter master cylinder in the same hydraulic system would increase the required pedal effort to stop the car and decrease the braking capabilities. If there is no problem with the master cylinder at all, I don't really see a dire need to replace it.