I will bet the front Jack cylinders are smaller(6k or 9k) and the rear are (12k or 16k) cylinders. SMALLER cylinders will indeed extend faster than the larger cylinders. The system puts out about 3000psi. the psi does NOT change at all. The smaller cylinders have a smaller displacement and that causes MORE fluid (faster extension) to enter the cylinder. The rears have a larger displacement and needs more fluid (slower extension). This is true of HWH systems and I will bet it is true of the Kwikee system. Why is this a concern anyway? What is happening that you think it is causing a problem? Doug