- Ask why are they called water pump pliers and the answer is a part most engines no longer have: the packing nut on an old water pump.
- That nut was round, grooved, and buried. A wrench wouldn't grip it and couldn't reach it.
- The proper name is tongue-and-groove pliers. "Water pump pliers" is British usage that stuck everywhere.
- Rick's pair earned their keep in this episode on a loose fuel shut-off solenoid, not a water pump.
- Murphy's stocks two sizes, 5" and 4", both $39.99. The 5" is the pocket pair.
1. The Fix That Saved the Run
Seven vehicles. Seven families. One day to hand them all over, spread across northern Arizona, with the kids in the truck and a schedule that has no slack in it.
Two cars in, the truck Rick is hauling with won't start.
He's cranking it. Nothing. And the man narrates his own bad luck the way he always does:
"Everything was going so well. Murphy's law."— I Gave 7 Blue Collar Families New Cars To Give Back
Then he says the quiet part, which is the part that makes the episode land. If this truck stays dead, five families don't get their cars today:
"This is concerning because if I can't get this thing running, we're not going to be able to deliver the rest of these cars. I'm going to have to get on Facebook Marketplace and buy another truck. So, this is a fuel shut off solenoid."— I Gave 7 Blue Collar Families New Cars To Give Back
The solenoid was loose. That's it. No parts, no shop, no tow. He finds it, gets a grip on it, snugs it up, and the fix takes about as long as reading this paragraph.
"Unbelievable, folks. Pretty sure that's the problem. It was loose. It's a good thing I got my pocket pliers."— I Gave 7 Blue Collar Families New Cars To Give Back
Five seconds later, from somewhere off camera: "Babe, try it." Five more, and the verdict: "We're in business."
A tool named after water pumps just saved a day that had nothing to do with water pumps. So where did the name come from?
2. Where the Name Came From
Straight answer: they were named for one specific fastener on one specific part.
Old water pumps didn't seal the shaft with a cartridge bearing the way a modern one does. They used packing, and the packing was held in place by a nut. As the packing wore, the pump wept, and somebody had to go in and snug that nut back down. The tool reference AboutMechanics puts it in a single line: pump pliers "originally were designed for the tightening and removing of water pump packing nuts."[1]
Picture the nut. It's round. It's got grooves rather than flats. And it sits low in an engine bay, behind a belt, with a fan in front of it.
Now picture trying to get an open-end wrench onto it. You can't. There's nothing for the jaws to sit on, and no room to swing even if there were. EngineerFix, an engineering explainer site, makes the same point about the space: the tool "provided the necessary torque and maneuverability that fixed-jaw pliers or traditional wrenches could not offer in the tight spaces surrounding the water pump housing," and the name "arose because the tool's unique design was perfectly suited to a common, yet challenging, maintenance task in early engine technology."[3]
So the name isn't marketing and it isn't a brand. It's a job description that outlived the job.
3. What Else People Call Them
Almost nobody agrees on what to call this tool, and the disagreement is geographic.
Wikipedia's entry on the tool records "water pump pliers" as British usage, and lists the rest: "plumbing pliers," "groove-joint pliers," "arc-joint pliers," "multi-grips or multigrips (Australian usage)," "tap or pipe spanners," "swan neck pliers," and "monkey pliers."[2]
The formal name, and the one that actually describes the thing, is tongue-and-groove pliers. Same page, and it's worth reading the mechanism before you buy a pair:
"Tongue-and-groove pliers are a type of slip-joint pliers." … "The lower jaw can be moved to a number of positions by sliding along a tracking section under the upper jaw."[2]
That sliding track is the whole tool. It's why one pair covers a range of sizes instead of one, and it's the difference between a cheap pair and a good one. On the 5" pair Murphy's stocks there are 13 adjustment positions, the jaws are self-locking on pipes and nuts, and the pivot runs in a box joint rather than a lapped one, which the product page describes as giving "high stability because of double guide."[4]
Cheap tongue-and-groove pliers flex at that joint under load. You feel it as the jaws going out of parallel, right before they slip and you skin a knuckle.
Push-button adjustment straight on the workpiece, 13 positions. Gripping teeth hardened to approximately 61 HRC. Box-joint pivot, pinch guard, chrome vanadium electric steel, forged and multi-stage oil-hardened. Limited lifetime warranty. The store's own page calls these "Wrecker Rick's favorite pocket pliers."
4. Do They Still Earn a Spot on a Modern Engine?
Be honest about this part: the packing nut is gone. Look at a modern water pump and there's nothing on it for these to grab. The job the tool was named after barely exists any more.
And the tool didn't go anywhere. Ask yourself what actually strands a truck on the side of the road. It's rarely the thing you brought a socket set for.
This episode is the whole argument in one repair. A fuel shut-off solenoid works loose. The engine bay is hot enough that Rick's wife says so out loud. The part is round, it's low, and there's a fan in the way. A socket has nowhere to go. A wrench has nothing to bite.
The pliers have both.
That's the pattern you'll keep running into: hose clamps, sensor bodies, fuel fittings, stripped heads, plastic collars, anything round with no flats at all. Every one of those is the packing nut wearing different clothes.
5. Which Size Belongs in a Truck
Murphy's carries two, and they are the same price, so the choice is only about where the tool lives.
| Cobra® 5" | XS 4" | |
|---|---|---|
| Adjustment positions | 13 | 11 |
| Adjusting | Push button, on the workpiece | Single-handed, by sliding |
| Teeth hardness | approx. 61 HRC | approx. 60 HRC |
| Gripping capacity | Not published | Ø 28 mm, flats to 24 mm |
| Head | Standard | Especially slim, narrow spaces |
| Pinch guard | Yes | Yes |
| Price | $39.99 | $39.99 |
The 5" is the one the store ties to Rick, and it's the one that does the widest range of work while still riding in a pocket. Take the 4" when the problem is access rather than grip: it's built for "optimum access in the narrowest spaces," and it closes on a 28 mm diameter at only 100 mm of tool length.[5]
One warning, and it comes from the store, not from us. Both product pages open by telling you to check what you're ordering. The 5" page: "Yes, they are only 5"… make sure you know what 5" looks like." The 4" page says the same thing about 4 inches.[4][5] Hold a tape measure up before you click.
13 positions, push-button adjustment, 61 HRC teeth. The widest range that still rides in a pocket.
Slim head, 11 positions, Ø 28 mm capacity at 100 mm long. For the gap the 5" won't fit.
Lightweight aluminium, three LED bulbs, laser-engraved logo. Finding the loose part is the hard half.
6. What They're Not For
Good tools get misused because they nearly always work. These are no different.
Toothed jaws bite. Biting is the point on a round part with no flats, and it's a problem on a hex nut you'll need to undo again next year. Put hardened 61 HRC teeth on a soft fastener and squeeze, and you have started rounding it. The tool won't tell you. The next guy will find out.
So the rule is the one the name already gave you. Reach for these when the shape is wrong for a wrench, when the access is wrong for a wrench, or when there are no flats at all. Reach for a socket every other time.
Rick's solenoid met all three conditions at once. That's why the pliers were the right call and not just the closest one.
None of this is rigging work, and the risks are smaller. They are not zero.
- Heat. In this episode the engine had just been cranking, and somebody says out loud how hot it is. A manifold and a hose will burn you long after the engine stops.
- Fingers. Both pairs carry a pinch guard, described on the product pages as preventing "operators' fingers being pinched."[4] That is a guard, not permission to put a hand between the handles.
- Fuel. The part in this episode was a fuel shut-off solenoid. Anything on the fuel side means no ignition source and no smoking, and it means cleaning up what you spill before you start the engine.
- Belts and fans. The packing nut these pliers were named for sits right where a fan and a belt run. Engine off before hands go in.
Sources
- AboutMechanics, "What are Pump Pliers?" Fetched and confirmed verbatim 2026-09-19. aboutmechanics.com/what-are-pump-pliers.htm
- Wikipedia, "Tongue-and-groove pliers." Fetched and confirmed verbatim 2026-09-19. en.wikipedia.org/wiki/Tongue-and-groove_pliers
- EngineerFix, "Why Are They Called Water Pump Pliers?" Fetched and confirmed verbatim 2026-09-19. engineerfix.com/why-are-they-called-water-pump-pliers
- Knipex Cobra® High-Tech Water Pump Pliers 5" product page — specifications and price. Fetched 2026-09-19. murphysdiesel.com/products/knipex-cobra%C2%AE-high-tech-water-pump-pliers-5
- XS Water Pump Pliers 4" product page — specifications and price. Fetched 2026-09-19. murphysdiesel.com/products/knipex-cobra%C2%AE-xs-water-pump-pliers-4
A Name From a Job That Went Away
Water pump pliers got their name from packing nuts on engines your grandfather worked on. Those nuts are gone. The shape of the problem isn't: round, low, hot, and nothing for a wrench to grab. Rick carries a pair in his pocket for a reason, and on a day with seven families waiting on him, that pocket pair was the difference.