flusher said:
Yep, got the ops, service and parts manuals.
The fuel filters and the high pressure fuel pump (the injection pump) are on the left side of the engine while the low pressure fuel pump (the primary pump) is on the right side. You have to loosen air-vent plugs on the filters and on the injection pump one at a time while operating the primary fuel pump with the manual lever on that pump.
Question: do you have to close the air-vent plugs while operating the manual lever to make fuel squirt out of the vents? If so, that makes the procedure a two-person job (or single-person job if you have arms like an orangutan). Or can you lever the pump until fuel squirts and then walk around to the left side of the tractor and close the air-vent plugs?
Just trying to gauge what kind of problems I might run into if I do this job by myself.
I've gone through that filter change/bleeding air scenario about 30 times over the years on my 150. It's relatively easy, but there can be times where it doesn't go quite "by the book".
Step 1. Shut off fuel petcock on bottom of fuel tank.
Step 2. Drain filters.
Step 3. Install new filters, leaving SLIGHTLY loose.
Step 4. Open fuel petcock. As fuel begins to leak around filter, tighten completely. (May need "persuasion" with lift pump to get fuel flow to filters)
Step 5. Open bleed screw on filter and bleed all the air bubbles using lift pump to force fuel to filters. When satisfied filters are bled, close bleed screw.
Step 6. Open (I REMOVE) LOWER CHAMBER bleed screw on injector pump. Work lift pump until good flow of fuel is running from that bleed point. Close and tighten that screw.
Step 7. Do same as step 6 with UPPER CHAMBER bleed screw.
Step 8. Crack open rear-most injector line fitting nearest to cylinder head.
start cranking over starter. Fuel should seep from that loosened fitting. At that point, you're close. Engine should fire. As soon as it does, tighten fitting.
At any point where proccess starts to "break down", go back and repeat. Any amount of air in the system will cause an "air lock" of sorts.
That's what always works for me. Your results may vary.