From VIN 50001 Onwards

The fluid return system from the brake accumulator spheres to the reservoir consists of a low pressure return hose from the front and rear accumulator. These hoses join onto two unions (UR70275) and then two further hoses (GMF1210) join up to the...

This is the low pressure return hose for the rear brake accumulator sphere.  Looking for the front hose, search part# GMF1299 1980-1998 From Vin 50001

This is the low pressure return hose for the front brake accumulator. It is the hose that fits directly onto the valve body.  Need the rear return hose, look up part# GMF1310 Suitable for all cars from VIN 55483 approx onward

This is the Front Accumulator Sphere to the Union Return Hose. 1987-1998 VIN 20001 onwards