Hi Ducks, It has been 40 years since I changed one.
This is the way I did it right or wrong:
1)Clean the pump and area around pump and blow with air gun.
2)Scribe line between pump and mounting on pump drive gear housing.
3)Remove front cover off pump drive gear cover.
4)Scribe a line on timing gear and pump drive gear. This line will be used during re-install of pump.
5)Disconnect all fuel and injector lines from pump and cover lines and port ends to prevent dirt contamination.
6) Loosen the 3 screws in the pump drive gear.
7) Remove 3 nuts from pump mounting bolts.
8) Remove 3 screws from pump drive gear.
9) Grab pump and wiggle and pull towards rear of tractor and pump should come out of drive gear. Be careful not to drop dowel pin into timing gear housing.
There is a paper gasket on the pump and the timing gear cover that should be replaced.
Re-install using reverse procedure and making sure scribe marks are aligned.
Here are some other posts from archives about BD-
154 and injection pump:
I also just rebuilt a BD154. I might note that the timing gear marks can be a bit deceiving due to the idler between the crank gear and the injection pump drive gear. Mine runs really nice. Fires right up after using the glow plugs when cold, but after she is warm, it takes right off.
Been a while since I've timed a CAV/Lucas injection pump, bear with me. If you pull the rectangular cover off the side of the pump (held on with 2 small bolts) you will see the side of the cam ring. It will have a scribe mark on it the you can see move in the window as you turn the pump driveshaft. When that scribe mark lines up with the square end of the snapring holding the cam ring in the pump body, the pump will be at start of injection. You need to know the static timing mark used for setting start of injection, usually either marked on the flywheel or front pulley, not sure on a 414, but on many engine it is right at TDC. Rotate the crankshaft in the direction of engine rotation, (to take up any lash in the timing gears) until the engine timing marks line up, with #1 cylinder on top of compression stroke. At that point match the marks in the pump and lock her down to the front plate. Turn the crankshaft back 45 degrees and bring it forward again and recheck both sets of marks. Readjust if needed, reinstall window cover plate and bleed pump. Guessing on fuel pump timing and getting too much advance can be fatal to the engine if it is expected to work hard. I refuse to use the external scribe marks on the pump and front front cover, seen them out by over 1/8 inch on a regular basis. Hope this helps.
Timing marks are on the flywheel and clutch-
housing cover. You have to take the dust shield off to see them. Set at TDC for #1 cylinder. If the CAV rotary pump is original - there is a scribe-line on the front mounting-flange that get lines up with mark on the engine. There is also a scribed line on the injection-pump rotor that you can't see unless you take of the timing window from the pump.
Pump has a 3 bolt drive hub with a pin in the drive gear that enters the drive hub groove for proper timing. Pump also has a scribe line on one flange ear that aligns with the scribe line on timing gear case. Don't need to time this one to remove and replace the pump. Only way to get it way off is if the gear is installed wrong.