Answer
Mar 15, 2025 - 02:41 AM
Ah yeah, classic Massey problem. After swapping the fuel filter on your 4225, you’ll definitely want to bleed the system — these older Perkins engines don’t always self-prime well and air-locks can keep it from starting.
Start by filling the new filter with clean diesel if you haven’t already. Then, there should be a little manual primer pump — usually on the lift pump itself. Crack open the bleeder screw on top of the filter housing and start pumping until fuel comes out steady with no bubbles. Once that’s done, tighten it up.
Next, move down to the injection pump. You’ll see one or two more bleed screws there. Crack the first one, pump again until clean fuel comes out, then tighten it. Do the same for the second one if there is one.
After that, you should be good, but sometimes you’ll need to slightly crack one or two injector lines at the top of the injectors, crank the engine until fuel spits out, then tighten them back down—only do this if it still won’t start after the bleeding steps.
Once it’s bled properly, it should fire up after a few turns. Just keep cranking in short bursts so you don’t overheat the starter.
