Well, all done, and it is as loud as ever. Damn. The book says that whine is caused by air in the fluid but there are no leaks that I can find. So I did some experimenting. With this particular model, the bleeding process is a little different. They want you to remove the reservoir cap and attach a bleeder tool. This tool seals the reservoir like the cap but has a barbed fitting so you can use a MityVac to apply 20" vacuum to the system. This draws out the air and you are supposed to be able to hold vacuum for a while. The Kent-Moore tool is available but it looks like a big bottle stopper with a tube through the middle and costs around $70. A less expensive tool is out there but it only says it fits "most" GM pumps. So I grabbed a spare cap, removed the spring loaded guts, cut off the dipstick, and drilled it for 3/8" threaded tubing. I even replaced the guts so the seal would be under clamping pressure like normal. I put a barbed fitting on the outside end and hooked it to my MityVac. This worked great and I put 20" vacuum, on the system while I worked the steering wheel back and forth (wheels up in the air). Right away I saw that the vacuum dropped rather slowly, but steadily. So I kept pumping it down as I worked the wheel and I noticed that at several spots, the vacuum dropped dramatically. A-HA! Leaks. But where? Then I noticed at those leak spots, I heard a gurgling sound like a baby pooping. So now I know there are leaks in the rack itself that are not leaking fluid, but air .Must be on the return side. My old pump was probably fine, but lacking visible leaks, who knew. Now I have to decide if I want to go through the headache of changing the whole rack unit, and hoses, on a 17 year old car.
