Posted December 24, 2015 by Jefferson Bryant Maintenance

Chevrolet/GMC Truck Water Pump Replacement Overview

So there you are, just cruising down the highway, rocking out to your favorite tune on the radio, having a good old time, everything is right in the world. Being a good, alert driver, you glance down to check your gauges; gas good, oil pressure good, volts sure whatever halfway between 12 and 16 means. Then you see that the water temp gauge is running a little high. It isn’t overheating, but enough to give you that tingly feeling in your chest; after all, you are 1,000 miles away from home in the middle of the Arizona high-desert. After a few miles, the dash lights up orange with a flashing warning “Low Coolant”. You see the sign for the next gas station and pull in, and that’s when you catch the faint whiff of hot antifreeze.

You hop out and see a small puddle forming under the engine. You already know what it is; it’s the lifeblood of your truck’s engine – the coolant. Luckily, you always keep a couple of jugs of water with you for these situations. As you crawl under the car in the parking lot of the gas station, you see a small flood of water pouring out from under the engine, you check the hoses, those are fine; you look to see if the leak is coming from the water neck, nope. Then you spot it – the weep hole. Great, not an easy fix. Your road trip just went from fun to roadside repairs. The internal seals of the water pump are shot. When the engine is running, coolant leaks, when the engine is shut off, it pours out. Luckily, the pump is functional for the moment. The local NAPA store in this town is closed late on a Saturday night, so you have to keep moving. Refill the jugs, head on down the road with one eye on the water temp.

This is exact situation we recently faced on a cross-country road trip. Luckily, the water pump did not fail, it maintained function throughout the first leg of the trip. We hit the closest NAPA Auto Part Store, in this case, NAPA Auto Parts on Valley View Rd in Las Vegas, NV, and picked up a new water pump. The store allowed us to install the parts in their parking lot and even let use a couple of specialty tools that we didn’t have on hand. We had the rest of the tools we needed in the travel tool box, if you don’t have a travel tool box, you need to put one together.

Water Pump Replacement Overview

A lot of effort goes into water pump replacement. We’re not going to walk you step-by-step through the entire repair, but we want to give you an idea of what kind of work is involved whether you choose to DIY or have your local NAPA AutoCare do it for you. Regardless, you’ll have a better idea of what kind of work a Chevrolet Silverado/GMC Sierra truck or Chevrolet Tahoe-Suburban/GMC Yukon-Suburban SUV, or Cadillac Escalade 4.8L/5.3L/6.0L Vortec V8 water pump replacement requires.

Note that any repairs made to the cooling system must only be attempted once the vehicle’s engine has cooled. The radiator hoses should be cool to the touch and the system no longer under pressure. The radiator hoses should be soft when squeezed verifying the system is no longer under pressure before removing the radiator cap.

First, the air box and engine air inlet hose are removed to expose the upper radiator shroud.

Then you have to get the radiator fan shroud out of the way by tilting it backward and upward.

Next, all the radiator hoses and cooling hoses need to come off the old pump. Put a drain pan under the front of the engine to catch any coolant what leaks out during the water pump replacement process.

Taking off the fan requires a special tool, which your mechanic will already have or you will need to buy from your local NAPA AUTO PARTS store. This tool holds the pulley in place while the fan is removed. — Taking off the radiator cooling fan requires a special tool, which your mechanic will already have or you will need to buy from your local NAPA. This tool holds the pulley in place while the fan is removed.

The serpentine belt comes off next, then it is on to removing all the bolts that hold the water pump in place. Here is where experience or a good shop manual pay off. Unfortunately water pump bolts are notorious for breaking, so care must be taken. This is one step that may be best left to the professionals, because if a bolt snaps in the block things get a lot more complicated. If you choose to DIY, put down the power tools and loosen the water pump bolts by hand. A good soaking of the water pump mounting bolts with penetrating lubricant is also a good idea.

The old water pump gets tossed in the scrap metal recycling bin and the new water pump gets prepped for installation with fresh gaskets.

Now everything goes back on in the reverse order that it came off. Now is the time to replace any hoses which are swollen, cracked, mushy or suspect since you are already in there.

Once everything is back together it is time to top off the coolant tank and bring the engine up to running temp before topped off again. Do not replace the radiator cap until the engine has reached operating temperature and the overflow tank is filled to the correct level. At this point the radiator cap can be installed. Coolant that escaped into the drain pan can now be disposed of properly according to local laws.

These kinds of emergency repairs can happen to anyone at any time, so be prepared and don’t get caught off guard. Now that you have an idea of what water pump replacement takes you can decide if this is something you can tackle on your own or let your local NAPA AutoCare expert handle for you.

Check out all the heating & cooling systems parts available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on water pump replacement, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Jefferson Bryant View All

A life-long gearhead, Jefferson Bryant spends more time in the shop than anywhere else. His career began in the car audio industry as a shop manager, eventually working his way into a position at Rockford Fosgate as a product designer. In 2003, he began writing tech articles for magazines, and has been working as an automotive journalist ever since. His work has been featured in Car Craft, Hot Rod, Rod & Custom, Truckin’, Mopar Muscle, and many more. Jefferson has also written 4 books and produced countless videos. Jefferson operates Red Dirt Rodz, his personal garage studio, where all of his magazine articles and tech videos are produced.