Paccar Water Pump Replacement Question

In what chasis and mileage? I usually just drain the whole cooling system. If over 400,000, I would change the coolant. Most Pete and KW are around the 12 gallon of coolant.

 

Buy some buckets. You will have to drain more than 3/4 of the coolant when changing the w/p. Should be a drain fitting in lower radiator pipe, 5/16 Allen wrench if I recall correctly.

 

Dont mess around with trying to drain it partway. Just dump it all out and refill it. You will make more of a mess with the system partially empty.

The drain plug in the lower steel pipe is 5/16" or 8mm allen. The pipe thread size in the pipe is 3/8NPT. I ussually put in a brass draincock as the allen strips easy and is a PITA to work with.

 

To save yourself some headache.......there are holes in the belt tensioners to lock them open or in the loaded position. Line up the holes and slide an allen wrench in to lock it open. I think its 5/32" that fits the hole. Makes belt installation a breeze.

 

When you buy your water pump, make sure you get just the cartridge. Also, large o-ring doesn't come with it.