How-tos

A P0402 code tells you too much exhaust gas is being recirculated back into the engine—and that means power loss, black smoke, rough idle, and limp mode on excavators, dozers, loaders, and tractors. In this guide, we’ll cover what to look for, what’s actually causing it (carbon buildup from too much light-load running, vibration-cracked piping, and plugged Delta-P sensor lines), and a step-by-step fix: check live data, inspect the piping, clean the sampling ports, test the EGR valve, and check the wiring. One thing to avoid: don’t start by replacing the EGR valve. A good cleaning of the valve and sensor lines clears up most cases. A few prevention habits—cutting down on idle time and keeping up with crankcase filter changes—go a long way toward keeping P0402 from showing up again.

This guide explains the John Deere throttle linkage diagram for Briggs & Stratton and Kawasaki engines. Learn what each linkage part does, how to adjust the throttle and choke cables, and how to troubleshoot common throttle problems on your John Deere mower.

A good wheel loader service routine is all about catching wear early—before it drags down cycle times, leaves the bucket feeling weak, or puts the machine in the shop. In this guide, we’ll run through the usual trouble spots: bucket teeth, cutting edges, pins and bushings, tires, brakes, articulation joints, and hydraulic hoses. And we’ll point out what to watch for—teeth worn down to nubs, a bucket that fits loose, knocking from the linkage, drifting cylinders, or a whine from the hydraulics. Get into the habit of a daily pre-shift walk-around—check teeth, look for leaks, inspect hoses and tires, and cycle the articulation—and spotting wear becomes routine. Swap parts before they take out something else further down the line. Stick to your schedule, but don’t ignore the unexpected—if you hear metal knocking or feel the brakes getting soft, stop and inspect right away.

The cabin air filter in your CAT machines plays an essential role in preventing dust and dirt from infiltrating your machine’s systems. Whether you choose to purchase new cabin air filters from the manufacturers or from aftermarket suppliers, it’s crucial to know how to select the right cabin air filters. In this guide, we’ll walk you through the steps to replace the cabin air filter on your CAT equipment.

Understand your mower’s drive system with our detailed Cub Cadet drive belt tension spring diagram. This guide explains each component, helps you diagnose common problems like a stretched spring, and provides a step-by-step replacement tutorial.

Keeping up with a solid wheel loader service routine means you catch wear early—before it turns into slow cycles, a weak bucket, or a machine that’s stuck in the shop. This guide covers the usual suspects: bucket teeth, cutting edges, pins and bushings, tires, brakes, articulation joints, and hydraulic hoses. Watch for the telltale signs—teeth worn down to nubs, a bucket that feels loose, knocking sounds from the linkage, cylinders that drift on their own, or a whine from the hydraulics. A quick pre-shift walk-around every day—check teeth, look for leaks, inspect hoses and tires, and work the articulation—makes wear detection a habit. Swap parts out before they take something else out down the line. And don’t just rely on the schedule—if you hear metal knocking or feel the brakes going soft, stop and look into it right then.

Valve cover gasket leak symptoms—oil weeping around the cover edge, sludge building up, that distinct burning oil smell, and oil showing up on lower engine surfaces—often start small but get worse over time. This guide covers how to spot an active leak, tell it apart from other upper-engine issues like a loose filler cap or a blocked breather, and figure out when it’s time to stop putting the repair off. We’ll walk through a practical five-step inspection process: clean the area and recheck, pay close attention to corners and bolt holes, trace oil tracks upward, check hot spots, and verify the oil level. Catching it early saves you from oil loss, fire risk, and the cost of replacing oil-soaked hoses and wiring on tractors, excavators, and loaders.

Electrical issues can bring your John Deere equipment to a sudden halt. Knowing the John Deere fuse box diagram is essential for quick diagnostics and repairs. In this guide, we’ll walk you through everything about the John Deere fuse box, from the locations, the diagrams and how you can troubleshoot problems with it.

Wondering how many glow plugs are in a diesel? Most engines feature one glow plug per cylinder, but some use a single manifold heater. This guide explains the rule, covers different setups, and shows you how to spot failure signs.

Smoking, overheating, and power loss on diesel engines—especially tractors and skid steers that idle a lot—often trace back to carbon buildup. In this guide, we’ll take you through a six-step cleaning process: get the machine ready, open up access, scrape or blast away heavy deposits, run a chemical cleaner through, check the components, and button it back up. We’ll also look at where carbon collects (valves, pistons, EGR, turbo), help you decide when a cleanout is enough and when you need to replace parts instead, and give you some solid habits to keep carbon from piling up again—cut back on idling, use good fuel, and keep up with filter changes. One more thing: on Tier 4 machines, pull those fault codes first. If the DPF is plugged or the turbo is shot, cleaning isn’t going to fix it.

A lawn mower pull cord stuck can be frustrating. Our guide simplifies the fix. Use our symptom chart to diagnose the cause, then follow easy steps to clear a blocked blade, fix hydrolock, or repair the recoil starter.

Whether you’re troubleshooting a lawn tractor that won’t start or replacing a worn-out switch, understanding how your ignition switch works is essential. This guide walks you through everything you need to know about the 5-pole ignition switch diagram, from reading terminal labels and wiring connections to testing and diagnosing common failures.