There’s no shortage of used rigs on the market, especially in the 1500 HP range—but not all are created equal. Some have been babied and maintained like aircraft. Others… not so much.
At Power Drive Supply, we’ve seen both ends of the spectrum. We’ve bought rigs that were turnkey-ready and others that needed a month in the yard just to get mobile. So whether you’re eyeing one of the rigs we’ve got listed—or you’re sizing up a unit somewhere else—here are five key things you’ll want to inspect before making the purchase.
This checklist isn’t just about protecting your money. It’s about keeping your team safe, keeping downtime to a minimum, and making sure what you’re buying can actually get to work.
1. Start with the Mast—It Tells You Everything
Before you worry about power systems or paint, walk straight to the mast. That’s where you’ll see the story.
- Look for structural fatigue: Check welds, pinholes, and upright braces. Any signs of patching or misalignment are red flags.
- Inspect sheaves and crown: Grooves should be even, and bearings should spin freely. Replaceable? Sure. But good gear here is a good sign overall.
- Check guide rails and wear pads: These will tell you if the rig was operated with care or just pushed to failure.
If the mast is bent, cracked, or heavily modified, walk away. No deal is good enough to inherit a problem like that.
2. Hydraulic Systems: Pressure and Cleanliness Are Non-Negotiable
A walking rig lives and dies by its hydraulics. If the rams aren’t strong or smooth, you're buying a headache.
- Test walk speed and leg retraction — It should move with purpose, not hesitation.
- Check for leaks, film, or scoring on rods — Seals should be intact.
- Inspect hoses, fittings, and return lines — Dry and tight is what you want.
Take a sample of hydraulic fluid if you can. If it smells burnt or looks milky, you’ve got water or overheating in the system. Either way, not ideal.
3. Power Train: Does the Heart Still Beat?
Whether the rig’s powered by a CAT 3512, a Cummins QSK series, or something else entirely, the engine and drawworks should be next on your list.
- Engine start-up: Cold starts matter. If it takes forever to catch or smokes like crazy, dig deeper.
- Check engine hours vs. rebuild records – If a 20,000-hour motor hasn’t seen a wrench since Obama was in office, keep that in mind when pricing.
- Drawworks function: Pull the line, test braking, and listen for gear noise.
Rebuilding a power end is doable—but not cheap. If you’re walking into a rebuild, factor that cost into your offer.
4. Electrical & Control Systems: A Modern Necessity
A lot of 1500 HP rigs from the last decade come with upgraded controls. That’s great—until they fail.
- Test all safeties, alarms, and limit switches
- Verify panel integrity, breakers, and wiring routes
- Run through a simulated start and stop sequence
Make sure the walking mechanism, mud pumps, and top drive (if equipped) can be controlled smoothly. If a control board is fried, you’re potentially waiting weeks for a part—especially if the system is no longer in production.
5. Undercarriage & Walking System: Can It Move When It Needs To?
Don’t forget: a walking rig is only as mobile as its legs.
- Inspect each foot for signs of uneven wear or misalignment
- Check walking cylinders for chrome damage or seal leaks
- Look at bolt torque on skids, rails, and mounting points
A rig that walks poorly doesn’t just frustrate the crew—it chews up your pad and slows down your timeline. Good legs mean flexibility when your location or program shifts.
Bonus: Ask for Service Logs, Not Just a Sales Sheet
At Power Drive Supply, every piece of equipment we list comes with full documentation, service history (where available), and a walkaround video. That’s how we do business. But if you’re buying from somewhere else, don’t be afraid to ask for receipts. A good seller should be able to show what’s been replaced, when, and by whom.
Why It Pays to Shop with Power Drive Supply
We’ve got skin in the game. Our team isn’t made up of warehouse clerks—it’s former operators, techs, and field service guys who know what downtime costs. When you buy a used rig from us, you’re not guessing. You’re getting:
- Verified inspections
- A ready-to-work unit
- Straight answers, no fluff
And if the unit needs a few touch-ups or additions before it fits your site spec? Let’s talk and we’ll make that for you.
A Great Investment That Goes a Long Way
Buying a used 1500 HP walking rig is a major investment, but with the right checks in place, it can be one of the smartest moves your team makes this year. Ask questions, get dirty, and don’t settle.
Got a rig on your radar? Reach out. We’ll go over it with you, share what we know, and if we’ve got something better in stock, we’ll tell you straight.