This is the Kubota manual for the L1720 front loader, a combined parts catalog and hydraulic service guide. It covers the loader as fitted to the L345 tractor family, with the exploded parts diagrams, general specifications, and step by step hydraulic testing you need to keep it working.Across 50 English PDF pages you get directional and serial number references, general specifications for the cylinders, valve, relief valve setting, and pump, a logical troubleshooting routine, flow meter and non-flow-meter hydraulic tests, and full parts breakdowns for the pump, control valve, cylinders, and frame.Owners, restorers, and independent mechanics can use it to identify and order the right parts, test pump flow and relief pressure, and rebuild the cylinders and control valve. Download it, keep it on any device, and print the pages you need at the bench.
What's Inside This Kubota L1720 Parts Manual
| System | Pages | Key Topics |
|---|---|---|
| Introduction | - | Directional Reference |
| General Specifications | - | These Specifications Apply to, Valve, Relief Valve Setting, Pump |
| Safety | - | - |
| Tools and Test Equipment | - | General Torque Specification Table |
| Logical Steps to Trouble Shooting | - | Question the Customer and Operator, Make a Complete Physical Examination, Have Operator Simulate Problem, Then Try It Yourself, Verify the Performance of Major Systems |
| Trouble Shooting | - | Loader Fails to Raise, Slow or Erratic Lift, Lift Arms Not Lifting Equally, Loader Does Not Have Adequate Lift, Or Break Out Capacity |
| Flow Meter Testing | - | What Is a Flow Meter, Preliminary Checks (Oil Level, Check the Oil Filter and Replace As Necessary), Connecting the Flow Meter Test 1, Test 1 Pump Flow, Conclusion |
| Hydraulic Testing Without Flow Meter | - | Test 1 Relief Valve, Conclusion, Load Check Valve, Test 2 Load Check Valve (Lift Circuit, Bucket Circuit), Test 3 Internal Cylinder Leakage |
| External Hydraulic Pump | - | Drive Gear Shaft, Housing Sections, Screws, Washers, Driven Gear, Drive Gear, Dowel Pins, Wear Plate |
| Control Valve | - | External Leakage, Excessive Internal Leakage, Spool Binding, Disassembly, Inspection, Reassembly |
| Cylinders | - | Headcap, Rod, Piston Nut, Piston, Spacer, Head, Wiper Seal |
| Parts Catalog | - | O/L, Nss, Terms, Right & Left Hand, Catalog Changes, Parts Order, Bucket Level Indicator, Main Frame / Sub-Frames / Mounting Brackets |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Piston nut torque | 165 ft-lbs (22.8Kg-m) | p. 29 |
| Headcap torque | 25 ft-lbs (3.5Kg-m) | p. 29 |
| Hose, 1/2" x 26" | 1/2" x 26" | p. 35 |
| Hose, 1½" x 18" | 1½" x 18" | p. 35 |
| Lift Cylinder Bore | 2" dia. | p. 5 |
| Lift Cylinder Rod Diameter | 1.50" dia. | p. 5 |
| General Torque for 5/8" (15.88mm) Grade 5 Bolt (Min) | 150 ft-lbs (203.4 Nm) | p. 9 |
| General Torque for 5/8" (15.88mm) Grade 5 Bolt (Max) | 180 ft-lbs (244.1 Nm) | p. 9 |
| Maximum Lift Height (L345 Tractor) | 113.5" (2883mm) | p. 5 |
| Break-Away Capacity (L345 Tractor) | 2550 lbs. (1150Kg) | p. 5 |
| Lift Capacity at Full Height (L345 Tractor) | 1495 lbs. (680Kg) | p. 5 |
| Bucket Cylinder Bore | 2" dia. | p. 5 |
Kubota L1720 Common Problems This Manual Covers
Loader lifts slowly or erratically
Air in the system after service, low fluid, or leaking fittings cause slow or erratic lift. The troubleshooting section isolates the cause before you move on to testing.
Manual Section: Slow Or Erratic Lift p. 11Loader lacks lift or breakout force
Weak pump output, a relief valve set low, or a clogged filter limits lift and breakout capacity. The troubleshooting chart points you to the right hydraulic test.
Manual Section: Loader Does Not Have Adequate Lift, Or Break Out Capacity p. 12Bucket or arms drift down in neutral
Internal leakage past worn cylinder seals or a worn spool lets the load settle with the controls in neutral. The leak-down check confirms which part is at fault.
Manual Section: Leak Down Of Cylinders p. 13Hydraulic pump noisy or overheating
Air drawn in on the suction side, contaminated fluid, or a low oil level makes the pump chatter and run hot. The troubleshooting section covers the noisy or overheating pump.
Manual Section: Hydraulic Pump "Noisy" And/Or Overheating p. 13Weak lift from internal cylinder leakage
A cylinder leaking internally past its piston seal loses lift under load. The internal leakage test verifies the cylinder before you commit to a rebuild.
Manual Section: Test 3 Internal Cylinder Leakage p. 22Frequently Asked Questions
Does this manual list part numbers for the L1720 loader?
Yes. It includes exploded parts breakdowns for the pump, control valve, cylinders, hoses, and main frame so you can identify and order the right parts.
What loader does it cover and on which tractor?
The L1720 front loader, with general specifications given for the L345, L345DT, and L355SS tractor fitment. p. 5
Can I test hydraulic pump flow and relief pressure with it?
Yes. It includes flow meter and without-flow-meter procedures; the flow testing begins in the Flow Meter Testing section. p. 14
How do I diagnose a loader that will not raise?
Start with the logical troubleshooting routine, which questions the operator and checks the systems in order before you run specific hydraulic tests. p. 10
Is this Kubota L1720 LOADER Parts Catalog a digital download?
This is a 50-page searchable PDF that downloads the moment checkout clears. It opens on a laptop, tablet, or phone, so you can take it straight to the shop floor.
Is this Kubota L1720 LOADER Parts Catalog printable?
Yes. Print as many copies as you like, with no restrictions. Most mechanics just run off the one section they need and keep it on the bench.
Reviews
There are no reviews yet.