A set of engine seals (front only) costs about $40. It is generally well worth the little expense and time to go ahead and replace the seals if you're "in the area" replacing a water pump. You may need more than seals though, the oil pump sleeve and the balance shaft spacers will occasionally be worn too. It is difficult to know this until you have the parts separated for inspection. This situation often means that the job will take several days while needed parts are first determined and then ordered/shipped.
Here's a tip for removing the crankshaft key, a sharp pair of dykes - works most every time. With the key out, I can remove the old seal. Here is an old shade-tree trick that works, just be sure to drive the screw in near the outer edge of the seal. Caution, take care to not allow the screw to touch the crankshaft - scratching the crankshaft would be really bad.
Here are the removed parts from the crankshaft (machine washer not shown). Inspect the oil drive sleeve for a groove (worn into it by the lip of the seal). If you can catch your fingernail on the groove, then it should be replaced. The new seal gets tapped into place with a large socket. Tip: if, for some reason, you are changing the lip seals (like the one on the crank) and don't have a replacement for a worn (grooved) sleeve. It is possible to install the new seal leaving the edge the seal a millimeter or two proud of the pump. Doing this causes the lip of the new seal to ride on slightly different spot on the sleeve and make a better oil seal.
Balance shaft keys are gently tapped out - the half moon shape makes them easy to get out. These small parts are easily lost, so beware. Each of the two balance shaft front covers are removed to the workbench.
There are several small parts used to mount the power steering pump, this (above) dirty photo is to remind me which small parts go where. This is a good time to spend a few minutes cleaning up the front of the engine. Some spray brake cleaner and a small brush will do a nice job cleaning things up but the fumes can affect your breathing for a lifetime. Autozone has a product called Superclean that is my current favorite. It is safer but takes more time (squirt on, wait 10 minutes, rinse off). Its pretty harsh so don't leave it for long. I always do better work with the grease and grime out of the way.
You can see the socket that I used to drive the spacer (sometimes referred to as a sleeve) & seal from the back side of the cover. Once I'm satisfied with the condition of the spacer and the bearings, I simply insert the spacer into the new seal and press the new seal into the front cover. A simple bench vise is perfect for doing this. Special note: the two balance cover seals look similar but are actually different. There is a right and a left and can be distinguished by looking at the ridges on the inner lip surface of the seal. The ridges are angled to direct the oil back into the engine during shaft rotation (remember, the shafts rotate in opposite directions). The seals must be re-installed carefully.
All that is left to do is replace the onion skins, these are small Mylar seals, similar in shape to very thin washer with a diameter roughly equal to a US quarter; nicknamed: onion skin seal. If you forget the onion seals, you will almost certainly have a large oil leak.
With those in place we can re-attach the balance shaft front covers . The lower balance shaft cover is also known to be problematic and must be installed by bringing up the torque on the three bolts evenly. Once secured, check the shafts to be free to rotate, they should have very little drag.
Note: some will observe that I did not "do" the cam seals. Frankly I don't routinely do the cam seal because they very seldom leak and its a real pain to get the cam gear off.
If you must "go there": here is a photo of the various parts. Expect to have to drill the head off of the long cam bolt using a 3/8 bit. So best to have a new bolt on hand.
Photo courtesy of "Granite 944"
