How To Change Fuel Filters and Bleed Yanmar 3JH2E Marine Diesel

Change Primary Filter

These instructions are appropriate for the Parker Racor 500 series primary filter system. The details may differ for your situation, but the general principles apply.

  1. Primary filter is Parker Racor 2010SM-OR 2 micron.
Parker Racor 2010SM-OR 2 micron primary fuel filter.
  1. Wear nitrile gloves. Prepare a plastic bag in which to discard items.
  2. CLOSE fuel valve (valve handle should be vertical).
Close the fuel valve.
  1. Place oil pads under primary filter housing.
  2. Open top of primary filter housing by removing the vacuum gauge assembly with a 3/4″ wrench.
  3. Remove rubber o-ring from primary filter housing lid.
  4. Find handles on fuel filter and lift out of the housing. Use a screwdriver if necessary to help access the handles.
  5. Clean out bottom of filter housing?
  6. Open new filter package. Set aside the additional parts from the package.
  7. Place new fuel filter into the housing.
  8. Install new o-ring into the housing lid. Make sure the o-ring is installed without twists.
  9. Replace the o-ring on the vacuum gauge assembly screw.
  10. Screw the vacuum gauge assembly back into top of the filter housing. Tighten with wrench but do not overtighten – overtightening can crack the lid.
  11. OPEN fuel valve (valve handle should be horizontal).

Change Secondary Filter

  1. Secondary filter is Yanmar part number 129470-55810.
Yanmar fuel oil filter 129470-55810 for 3JH2E
  1. There will be a lot of fuel in the filter—prepare a jar in which to pour the fuel out of the old filter.
  2. Place oil pads around and under the filter.
  3. PULL engine stop cable (stops fuel flow).
  4. Use oil filter wrench to remove to old filter. The old filter will be full of fuel—try to avoid spilling.
Location of secondary fuel filter.
The secondary fuel filter.
  1. Pour excess fuel out of filter and into a jar. Discard filter.
  2. Never put fuel into the secondary filter before installing it! Doing so increases the risk of getting contaminated fuel into the system. Install it dry and prime via the lift pump.
  3. Lubricate gasket at top of filter with some diesel fuel.
  4. Screw new filter into place. Stop when you just start to feel resistance. Then use the oil filter wrench to tighten one more full turn.
  5. DISENGAGE (push in) engine stop cable (permits fuel flow).

Bleed Fuel Lines

Diagrams and a description of the bleeding process can be found in section 6-3 “Air bleeding” (page 29) of the JH(2) Series Diesel Engine Operation Manual.

  1. Make sure engine stop cable is DISENGAGED (pushed in).
  2. Make sure fuel valve is OPEN (valve handle should be horizontal).

3. Set throttle to 50% (not in gear).

  1. Slightly open secondary fuel filter output bolt (the middle one) on top of the secondary fuel filter housing with a 17 mm socket wrench.
Fuel filter output bolt.
  1. Find the lever on the fuel pump.
Location of fuel pump.
Fuel pump lever detail.
  1. Note, when initially depressing the lever handle, it may get caught on the pump body. If this is the case, gently push the lever below where it gets stuck. It is below this point where depressing the lever actually results in pumping.
  2. Pump the lever until fuel streams out of the secondary fuel filter output. (This could take a while—200 or more pumps of the lever—if you’ve just replaced the secondary fuel filter.) Tighten the bolt while gently pumping so the the bolt is tightened as fuel is flowing.

8. Loosen the injector pump input bolt with 17 mm socket wrench. Pump the lever until fuel streams out. Tighten the bolt while gently pumping so the the bolt is tightened as fuel is flowing.

Injector pump input bolt.
  1. Loosen the fuel return input bolt (the right-most one when facing the front of the engine) on top of the secondary fuel filter housing with a 12 mm socket wrench.
Fuel filter return bolt.
  1. Pump the lever until fuel dribbles out. Fuel will not stream out as before, since the fuel return line is also connected here.
  2. Tighten the bolt while fuel is dribbling out. Watch for when the fuel rises and spills out a bit before going down the return line. Try to tighten the bolt while the fuel is rising.
  3. Clean up any spilled / dribbled fuel.
  4. Double-check and tighten bleed point bolts.
  5. Loosen all three injector nuts one full turn with a 17 mm wrench.
Injector nuts.
  1. Tug gently upward on each injector line, to unseat it a bit from the injector.
  2. Wrap each injector nut with a bit of paper towel.
  3. Ensure raw water intake seacock is CLOSED. Otherwise, engine may back flood with salt water while cranking which would likely destroy the engine!
  4. Crank the engine for 10 seconds.
  5. Check the paper towels around the injectors. They should all have a roughly equivalent amount of fuel on them, maybe about 1.5″ diameter blot on the towels.
  6. If this is not the case, replace with fresh paper towels around the injectors, wait 60 seconds, then repeat from the cranking step.
  7. Tighten all three injector nuts to torque specified in manual.
  8. Ensure raw water intake seacock is OPEN.
  9. Return throttle control to the IDLE position.
  10. Start the engine. It may be a little rough in the first minute of operation.
  11. Test in neutral at 2,000 rpm and under load (forward gear) at 1,500 rpm. Engine should run smoothly.
  12. Check for leaks at fuel lines, filters, and bleed points.
  13. Grab a beer and relax.

8 replies on “How To Change Fuel Filters and Bleed Yanmar 3JH2E Marine Diesel”

A second thank you! I have a 4JH3E and everything looks remarkably similar. The bleeding instructions in the Yanmar manual are clear enough, but none of the referenced parts are diagrammed or labeled. Yours is very well documented and labelled. Just what I needed. Again, thanks!

THANKS so much for this! I just bought Reverie, a 1983 Tayana 37, and these instructions and photos are SO much better than what is in the owners manual for the 3JH2E.

Thanks very much for your Yanmar 3JH2E filter change/bleeding instructions and photos. I have a Yanmar 4JH2-TE in 1991 Hunter 42 Passage that is very similar. Your bleeding procedure was perfect and helped greatly to get my engine running, after it sat idle for many years. Much appreciated!!!

Thanks mate,
this was a great help to do it on a
Very helpful and much appreciate it

Best regards
S/Y Legolas (Meridian 31)

Chuck. Good work here, thanks. Question is, in the case of a fuel tank cleaning wherein all fuel is emptied, tank is wiped down and new fuel added, can you foresee any additional steps required beyond what is outlined here to bleed the system (given the air gap is more pronounced)? My thoughts are that no extra steps are required other than additional pumping of the lift pump lever. I’d value your thoughts. Thank you. Curt

Hey there Curt, thanks for stopping by! I did that exact thing several years ago, and while I don’t recall specifically what I did then, I’d just say keep an eye on the primary fuel filter housing. It might make sense to top it off with clean diesel, if for no other reason than to minimize the amount of manual finger pumping that would otherwise be needed to fill it via the fuel pump lever. (It’s about two hundred presses of the little lever as it is!) It may even be necessary; there shouldn’t be any air in there at the top. Other than that, no, I can’t think of anything additional that’d be needed. Hope that helps and let us all know how it goes for you.

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