1998GS400 Brake Booster Noise

[rfcbuf]

My 1998 GS 400 (115,000 miles on vehicle) has a brake booster screech when applying brakes,especially when outside temp is cold. Screeching noise is usually quite short in duration and often goes away after driving for an extended time. I understand a new unit is quite expensive and is labor intensive to install. I'd like to know what options exist for repair. Also what would be expected if I just drive the car as is and wait until the pump fails to address the problem.

[lextechrob]

Labor should be 2.0 hours or less. Used unit is cheaper. If you can identify which part is the problem like the pump/ accumulator that can be bought separately new i think. car-parts.com is best place to look for used assembly- all of the electric boosters ( landcruiser, sc430, etc) are the same except for the reservoir