Jamaican71
03-16-2010, 10:35 PM
OK so I thought I would share a bit of advice from my experience swapping out the power steering pump on my '98 528i this past weekend. If anyone has a whining PS pump and is considering changing it, it is very straightforward and simple, but messy.
Raise the front of the car and place on jack stands to access the pump from underneath.
In order to get the pump out, you need only to release the tension on the drive belt and remove from the PS pulley. Three bolts hold the pump carrier in place and two lines are connected. (Reservoir to pump and pump return to cooling coils) That is where the mess is.
Drain and disconnect your res. to minimize fluid spillage. (I tipped mine into a gallon ziploc bag) Once the pump is off the car, you will need to remove the pulley and carrier. Three 10mm bolts for the pulley and 6 Torx screws hold everything together. The holes only line up one way, but take pictures before disassembly to keep from putting the brackets on in reverse.
I used two 10mm wrenches to break the pulley wheel loose. Just use one on a bolt as leverage while you loosen it's neighbor. Be careful as the OEM pulley is actually plastic!!!
When you reinstall the pump, you need to flush the system before connecting it to a new reservoir. Most threads I've read have said to turn over the engine (without starting) with the return line disconnected until clean fluid comes out. (Be sure to keep the res. filled) I found it much simpler to reconnect everything except the return line connection to the res.. That is where the filter is located. While the belt is still off, spin the pulley clockwise by hand with the end of the return hose in a gallon ziploc storage bag. Just turn and add fresh fluid to the res. until it comes out clean. My fluid was black when I started!!
Put a rag or two under the res. as you disconnect and reconnect lines to avoid a big mess. It helps to have a helper that can hold the res. up for you while you swap. In hindsight, I should probably have just replaced res. and lines, then flushed as soon as my pump started whining, but I procastinated to the point that the damn thing was louder than the engine, so I'm sure it was gone. I would suggest a flush to anyone with a noisy PS system first as a cheap and less messy preventative measure.
One thing I would add is that while it is not necessary, removal of the airbox and Maf assembly will give you plenty of room to work. When reconnecting the return line to the cooling coils be sure to put the o-ring on the end of the pressure fitting or leaks a plenty you will have.:D
It is still necessary to bleed any air out of the system once you are finished. Before lowering the car, simply start the engine, check for any leaks, then cycle the steering wheel back and forth lock to lock without stopping 7-10 times as needed. Recheck fluid level when you're finished.
Raise the front of the car and place on jack stands to access the pump from underneath.
In order to get the pump out, you need only to release the tension on the drive belt and remove from the PS pulley. Three bolts hold the pump carrier in place and two lines are connected. (Reservoir to pump and pump return to cooling coils) That is where the mess is.
Drain and disconnect your res. to minimize fluid spillage. (I tipped mine into a gallon ziploc bag) Once the pump is off the car, you will need to remove the pulley and carrier. Three 10mm bolts for the pulley and 6 Torx screws hold everything together. The holes only line up one way, but take pictures before disassembly to keep from putting the brackets on in reverse.
I used two 10mm wrenches to break the pulley wheel loose. Just use one on a bolt as leverage while you loosen it's neighbor. Be careful as the OEM pulley is actually plastic!!!
When you reinstall the pump, you need to flush the system before connecting it to a new reservoir. Most threads I've read have said to turn over the engine (without starting) with the return line disconnected until clean fluid comes out. (Be sure to keep the res. filled) I found it much simpler to reconnect everything except the return line connection to the res.. That is where the filter is located. While the belt is still off, spin the pulley clockwise by hand with the end of the return hose in a gallon ziploc storage bag. Just turn and add fresh fluid to the res. until it comes out clean. My fluid was black when I started!!
Put a rag or two under the res. as you disconnect and reconnect lines to avoid a big mess. It helps to have a helper that can hold the res. up for you while you swap. In hindsight, I should probably have just replaced res. and lines, then flushed as soon as my pump started whining, but I procastinated to the point that the damn thing was louder than the engine, so I'm sure it was gone. I would suggest a flush to anyone with a noisy PS system first as a cheap and less messy preventative measure.
One thing I would add is that while it is not necessary, removal of the airbox and Maf assembly will give you plenty of room to work. When reconnecting the return line to the cooling coils be sure to put the o-ring on the end of the pressure fitting or leaks a plenty you will have.:D
It is still necessary to bleed any air out of the system once you are finished. Before lowering the car, simply start the engine, check for any leaks, then cycle the steering wheel back and forth lock to lock without stopping 7-10 times as needed. Recheck fluid level when you're finished.