Mar 12th, 00, 11:37 AM
Can anyone out there tell me if a power steering pump for an 88 Olds Cutlass Supreme 2.8l v6 is interchangeable with a power steering pump for an 89 Olds Cutlass Supreme 2.8l v6? The pump for the 88 has a smaller pulley shaft than the one for the 89, but other than that there is no observable difference. Do both these pumps have the same pressure? Is there a reference book that tells the specs for both pumps? I emailed AC-Delco but they havent responded yet. I dont want to install the larger shafted pump if it has more pressure than the smaller shafted pump as I have already blown two rack and pinion units and just got done installing the third one. I bought a new pump yesterday,for an 89Olds, but am afraid to install it until I find out if it is interchangeable with the 88 pump. If anyone can help me with the specs for these pumps please do so. Thanks again for your time.
Mar 12th, 00, 04:16 PM
Pump pressure is regulated by a valve that is just behind the outlet fitting. Remove the fitting, the valve will come out as it has a spring behind it. The flat end goes toward the outlet fitting.
If the valves look similar, swap the origonal pressure valve to the new pump. Make shure you get it in right.
Mar 12th, 00, 04:37 PM
Thanks! Superb idea! What you are saying is that if the two valves are identical, then the pressures are the same for both pumps therefore they are interchangeable? I will do as you suggest and use the valve from the original pump. Any idea why GM went to a larger diameter pulley shaft on the 89 pump? Strenght? Durability? Belt tension too much for the smaller shaft? Again thanks for the reply!!!!!!
Mar 16th, 00, 04:08 PM
There are small washers on the relief valve that set the pressure.
The pulley size is selected either for oil volume needed at an rpm. Or belt fit and rpm relative to the other pulley sizes.
Shaft size is probably due to belt load. The older style pumps I,ve had apart had a bushing inside, no bearing. A larger shaft would bear more load.