The last thing I did today was to remove the water pump. I plan to replace the water pump with a new one because fortunately, new aftermarket water pumps are available for the E1 engine from Gates, part #42324.
The water pump on my truck, which is cast iron and I believe the original OEM water pump, only has one large outlet for the lower radiator hose. This set-up requires an in-line fitting to connect this plumbing to a long, smaller hose running from the top of the heater core.
However, the Gates pump, which is a later design perhaps for the J13 engine, has an integrated second, smaller outlet, to connect the heater hose. The Gates pump has the threading for the outlet, but does not come with a hose fitting, so I procured one (Moroso part #65390) and used an 18mm socket to thread it into the pump. The correct fitting for this pump and the hose is a 1/2″ barbed hose fitting with a 3/8″ Male NPT fitting.
Here’s a shot of the nice new Gates water pump ready to be installed.
I removed the old water pump from the engine. The water pump is attached to the block by three long bolts. I used a 1/2″ socket to remove those bolts.
With the three bolts removed, the water pump pulled off easily.
Inside the block there was some coolant, but it didn’t look like too much rust, mud, or other crud, which is a good sign.
Here is a side-by-side comparison of the two water pumps that highlights the location of the second water outlet on the new one.