GM Service Manual Online
For 1990-2009 cars only

Pump Type

Engine RPO

Special Option codes

High Flow Settings GPM

High Flow Settings LPM

Relief Valve Settings kPa (PSI)

ZF

L18/LB7

Hydroboost

2.9/3.8

10.8/14.4

11032-12390 (1600-1798)

ZF

L18/LB7/LG4/LG5

Hydromax

3.8/5.1

14.4/19.2

18617-19995 (2700-2900)

All pressures are with engine at normal operating temperature.