Part of the New Holland Repair Manuals.
A transmission pressure fault on the DC150.B crawler dozer is traced in the transmission troubleshooting section of this 375-page New Holland DC150.B service manual PDF, issued under OEM ID 603.67.081.00. Hydraulic schematics lay out the transmission, brake and steering circuits, and the dozer equipment section follows oil from pump and control valve to the blade lifting and ripper cylinders; an electrical schematic maps fuses, relays, diode boxes and connectors. Other chapters run from engine mounting and clutch overhaul to final drive removal, track chain tension, wear limits and refrigerant charging. Tightening torques sit in their own table. Check transmission pressure at 13.75 ± 0.5 bar with 10 lt/min flow, rising to 17.0 ± 0.5 bar at 70 lt/min. Your parts order for the 500-hour service starts with the delivery filter. Section bookmarks and a searchable text layer lead from troubleshooting chart to pressure check, so you finish the transmission repair to New Holland's own figures.
What's Inside This New Holland DC150.B Manual
| System | Pages | Key Topics |
|---|---|---|
| Generalities | 5-48 | Safety Rules, Identification Data, Table of Fluid Capacities, Table of Centre of Gravity, Main Dimensions and Weights, Tables of Technical Data, Check Data on the Machine |
| Engine | 49-60 | General Specifications, Engine Identification, Design Features, Serviceability, Engine Mounting |
| Transmission | 61-130 | General Description, Troubleshooting, Torque Converter, Clutch Overhaul, Special Tools |
| Final Drives | 131-154 | General Description, Final Drive Removal, Housing Cover, Gear Shaft, Front Seals, Special Tools |
| Brakes and Steering Differential | 155-256 | Brakes Hydraulic System, Steering Hydraulic System, Brake Pedal Valve, Steering Side Group, Bevel Gear Set, Special Tools |
| Undercarriage | 257-290 | Track Chain Tension, Idler, Track Chain Support Rollers, Bottom Rollers, Track Tensioner Device, Wear Limits |
| Dozer Equipment Hydraulic System | 291-320 | Hydraulic Circuit, Hydraulic Oil Tank, Equipment Hydraulic Pump, Hydraulic Control Valve, Blade Lifting Cylinder, Ripper Cylinder |
| Electrical System | 321-348 | Electric Diagram, Fuses, Instrument Panel, Monitor Senders, Display, Relay Group |
| Air Conditioning Unit | 349-373 | Operating Instructions, Technical Data, Service Precautions, Refrigerant Charging, Leak Inspection, Troubleshooting |
| Electrical Schematic | 374-375 | Fuses, Relays, Diode Boxes, Diverter Box, Connectors, Starter Motor |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Operating pressure | 31.5 to 35.0 bar (456.9 to 507.6 psi) | p. 35 |
| Transmission pressure (at flow of 10 lt/min, 2.6 gpm) | 13.75 ± 0.5 bar (3.6 ± 0.1 psi) | p. 26 |
| Transmission pressure (at flow of 70 lt/min, 18.5 gpm) | 17.0 ± 0.5 bar (4.5 ± 0.1 psi) | p. 26 |
| Maximum pressure (equipment/steering) | 190/350 bar (2755.7/5076.3 psi) | p. 35 |
| Delivery filter replacement interval | 500 hours | p. 165 |
| Delivery filter nominal rating | 30 µ | p. 165 |
| Transmission/torque converter oil filter tightening torque | 4 daNm (29.5 ft lb) | p. 128 |
| Transmission/torque converter oil filter by-pass valve setting | 2.5 bar (36.25 psi) | p. 128 |
| Securing screws, front bearing stop | 4.1 to 4.9 daNm (30.24 to 36.14 ft lb) | p. 119 |
| Securing screws, shaft hub stop | 4.1 to 4.9 daNm (30.24 to 36.14 ft lb) | p. 119 |
| Machine Services Link Fuse | 50 Amp | p. 328 |
| Alternator Link Fuse | 80 Amp | p. 328 |
New Holland DC150.B Common Problems This Manual Covers
New Holland DC150.B transmission lube oil low pressure indicator light comes on with engine running
Check transmission oil level on the dipstick and top up to the prescribed level. If the oil is foaming, hunt for an outer crack letting air into the pump. Clean the torque converter pump suction filter, change or clean the suction pipe or defective hose, and drain and refill if the wrong oil type is in it, following page 68.
Manual Section: Transmission Troubleshooting p. 68Transmission pressure normal in neutral but low with speeds engaged, machine starts hard in one direction
Measure forward and reverse clutch pressure against 16.5 to 17.5 bar per page 299. Before loosening any fitting, lower the equipment to the ground, stop the engine, cycle the levers without load and loosen the tank cap. Wash the transmission pump suction mesh filter, eliminate any leak drawing air, then clean the direction modulating valve plunger orifice and free a seized plunger (page 69).
Manual Section: Transmission Troubleshooting p. 69During normal dozing work the transmission oil temperature climbs and stays too high
Check the transmission oil level on the dipstick and top up with prescribed oil. Run the engine only with proper ventilation (page 72), then measure the temperature differential between the heat exchanger inlet and outlet. A marginal difference means a clogged exchanger is holding the safety valve open. Clean or replace the heat exchanger following page 70.
Manual Section: Transmission Troubleshooting p. 70Instrument display showing E with a three digit failure code on gear or steering solenoids
Read the 3rd, 4th and 5th display fields and match the code in table 1 on page 174: 001 left proportional valve, 002 right, 004 forward, 008 reverse, 016 1st gear, 032 3rd gear, 064/128 steering levers. Combined codes add up, so 024 means reverse plus 1st gear. Before inspecting that solenoid circuit, disconnect the battery ground cable as page 323 requires.
Manual Section: Electrical System Diagnosis p. 174Track chain adjusted too tight, machine pulls right or left and lacks pushing power
Check track chain tension on both sides; the tighter chain makes the machine turn and cuts traction and pushing capacity, per page 263. Recheck often when dirt packs between chain and tensioner, since it raises tension. Adjust at adjusting valve VR following page 264, but never relieve tension by loosening pressure relief valve VS or removing the grease fitting: fluid is under pressure.
Manual Section: Undercarriage Troubleshooting p. 263Cab air conditioner gives insufficient cooling although air flow and compressor operation are normal
Check the sightglass and compare low and high pressure sides per page 366. Bubbles or a cloudy flow with little temperature difference means low charge: repair leaks and recharge to the correct level. High pressure on the high side with no bubbles means overcharge: bleed off a small quantity into the R134a recovery unit (page 359) until bubbles appear periodically. Wear safety glasses and gloves; refrigerant causes frostbite (page 356).
Manual Section: Air Conditioning Troubleshooting p. 366Frequently Asked Questions
What are the tightening torque specifications for the engine support bolts on a New Holland DC150.B?
The tightening torque for the engine support screws (M24x2x80) is 41 to 45 daNm (302.38 to 331.88 ft lb). The screws (M16x1.5x50) have a tightening torque of 32.5 to 35.5 daNm (239.69 to 261.81 ft lb). p. 59
How do I calibrate the steering levers on a New Holland DC150.B using the BB3 instrument?
To calibrate using the BB3 instrument, connect the cable to the machine, set the starter key to 'ON', and move the switch to 'CAL'. Press 'F1' on the BB3, then 'ENTER' to set 0. When prompted, move the steering levers to stroke-end and press 'ENTER' again. The display will show 'ADJUSTED' when complete. p. 181
What are the replacement specifications for the transmission oil filters on a New Holland DC150.B?
The transmission delivery filter is a paper-filtering element that must be replaced every 500 hours of operation. It has a nominal tightening torque of 4 daNm (29.5 ft lb) and a by-pass valve set at 2.5 bar (36.25 psi). p. 128
What is the correct valve clearance for the engine on a New Holland DC150.B?
The intake valve clearance is 0.25 mm (0.009 in), and the exhaust valve clearance is 0.50 mm (0.020 in). p. 51
What is the procedure for checking the tightness of the front seals on the track rollers?
Connect a tool to the lubrication duct and inject compressed air at a pressure of 2 to 3 bar (29 to 43.5 psi). If the seals are efficient and correctly installed, no pressure drops should occur for about 15 seconds. p. 278
What format is this New Holland DC150.B manual in?
A 375-page Service Manual in searchable PDF format, available the moment you complete checkout. View on computer, tablet, or phone, with no shipping wait.
Is printing allowed for this New Holland DC150.B Service Manual?
Yes. Many mechanics print the section they need for their own shop and bring it to the bench.
