February 12, 2016

Yanmar 3GM30F Fuel Injection Pump removal - a boring technical post

Because I had a bit trouble with this job, I thought I'd write up all the steps required to pull the Fuel Injection Pump. It's also a useful reference if I ever have to do it again!

1.                  Remove air filter and cover. This uses 2 over-center clamps

2.                  Remove air filter base plate from intake manifold (3 bolts, 10mm socket)
(this step is to make removal of the aft most fuel injector fuel line possible)

3.                  Remove alternator from bracket and set aside. Leave wires connected. I figure most people reading this can find the alternator.

4.                  Remove the cooling water high temp switch wire (unscrew the ring terminal from sender at front of thermostat housing, on top of fresh water pump, on top of front of engine)

5.                  Yanmar seems to have made this engine first as a sea water cooled engine, so this step wasn't required because the engine didn't have a fresh water pump. Otherwise why make it so hard to remove the injection pump without removing the fresh water pump?

The fresh water cooling system will leak water all over the engine, so drain the fresh water system using the small valves at the aft end of the heat exchanger near the exhaust elbow and on the side of the block.

            Anyway, remove the fresh water pump. There are 3 hoses connecting the fresh water pump so loosen the hose clamps for each of these. (If these hoses are old and swollen, consider replacing them as preventative maintenance.) There are 4 bolts, 12mm wrench holding the pump in place. Do not loosen the smaller 10mm head bolt. These bolts are behind the water pump pulley so you cannot use a socket wrench and you will only loosen the bolts, not remove them.

6.                  Remove throttle lever nut and remove throttle lever (where the throttle cable connects). 12mm socket. But do not disconnect the throttle cable from lever.

7.                  Remove the small access plate from stbd. side of injection pump (right in front of the throttle lever). (3 bolts, 10mm socket). This will also remove the throttle stop screw on a separate plate marked in red.

8.                  Remove the fuel line connecting the engine mounted fuel filter to the injection pump (14mm wrench). There is an additional engine mounted bracket that requires removal (12mm socket) on my engine. Yanmar parts books shows several different types of fuel lines so just remove the one supplying the injection pump.

9.                  Getting closer now. Wipe up any dirt or debris around the fuel injection pump. Remove the 3 high pressure fuel lines from the pump and the fuel injectors. Loosen the forward most cylinder line / forward most connection on the pump and then proceed aft in turn. Use a 17mm wrench.

10.              After all high pressure lines are loose, remove the two clamp fittings (shown in blue above) holding the lines together and to the engine (10mm socket, 4 bolts total)

11.              Loosen the nuts holding the fuel injector pump to the engine block. The pump will be loose but still held in place.12mm socket with extension. You might need to break the seal between pump and mounting flange by prying gently with a screwdriver at first.

12.              Put a finger into the side access hole you uncovered in step 7. Feel for the throttle lever that pulls the fuel injection pump rack pin forward and back. You need to slide that lever backward or forward until it pulls free of the rack pin as you lift the pump slightly.

Now lift the pump while moving the rack pin forward or aft. There is a opening in the mounting flange shown on left picture below that the pin needs to pass through. Pull the pump up while simultaneously moving the pin forward and aft and the pump should come free. You do not need to force the pump if it is free of the flange. I repeat - don't force the pump. If comes free very easily if you have the rack pin lined up with the notch in the flange.
13.            Do not lose the thin shims between the pump and mounting flange. You will need these for reinstallation. Mine had 3 shims.

            When reinstalling the injection pump Yanmar specifies “Screw Lock Super 203M” between the shims. I think it’s pretty close to a blue Loctite 242 so that’s what I used. Remember that the thickness of these is critical to injection timing – so don’t use a thick silicone gasket sealer when re-installing. The governor case below is only splash lubricated with lubricating oil so it won’t take much to seal the pump to the mounting flange.

- Evan


Amy said...

Can't sleep? Body rhythm still messed up from traveling?

Diane, Evan, Maia and Charlie the cat said...

Yup = but getting better

Sherry said...

Dave wants to know WHY you are removing your fuel injection pump.

Diane, Evan, Maia and Charlie the cat said...

I pulled the pump because one of the delivery valves (where the high pressure lines connect) was leaking very badly. Maia's berth is right over the engine and smelly diesel in the bilge underneath was a headache.

James said...

Really helpful with removing the pump from my 2GM20. Thanks!

Unknown said...

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Unknown said...

Hi there,
My name is Gerard, I live in the west part of France. I loved your article about the fuel injection pump removal. I am confronted to the need too. I was just wondering the reason for step 7 (remove the small access plate...) My problem is the pump will not get out of its housing and I suspact it may have to do with incorrect position of the governor system.
Hope this is not bothering you too much.
Kind regards,

Anonymous said...

From what I understand. Its so you can put your finger into the hole and push back or forward on the throttle lever while pulling on the pump. This is to get it to disengage.

Unknown said...

Thanks. Actually, my pump was stuck badly enough so that the rack would not move to a position where the main lever lets the pump away up. So, yes, for this case, it was useful to remove the plate. But later, I have had to remove the pump several times for the timing adjustment and it is not necessary to remove the plate because the lever drives the rack and you can see the notch from outside before reinserting the pump. All in all, a fun game.

Gungemyster said...
This comment has been removed by the author.
Gungemyster said...

Great advise in this blog. Can you tell me how much movement there should be on the rack pin as I think mine has seized. It made it so difficulty to remove the pump!!
Mine moves about 1mm

Unknown said...

Omg! What a world we live in! Bloody knuckles and despair setting in that I overstepped my mechanical knowledge when I could not get my injector pump to release! So I turn to Mr Google and say “somebody help me!’ And......... up pops an annotated version of the yanmar manual. 20 seconds later my pump was free and I just thought..... that was close to miraculous! Can’t say how much I appreciate your post!

Bill from Bainbridge Island

Anonymous said...

I also have found this wonderful and extremely helpful write up. I linked here through Sailing Anarchy (Thank you Zonker). I have a small fuel leak at the high pressure fuel pump, it sounds like the same issue that you had, I can see it leaking very slowly at the base of the 19mm hex nut(what you refer to as the delivery valve) under the rear fuel-to-injector line. My question: Did you have to remove the whole pump assembly, to fix the leak? I'm hoping I can just modify a wrench and torque the 19mm nut a bit more, or that failing, remove the delivery valve and put new sealant(?) on it and reinstall, but without troubling to remove the whole pump assembly...can you tell me if doing it this way is possible? Thanks (aelxon@gmail.com)

P.S stinky diesel on a hot engine in a confined space is never any good, I smell it all through my boat. Enough is getting into the bilge that it puts a sheen on the water when I pump it out...gotta resolve this.

Anonymous said...

Note: You do not have to remove the fuel injection pump, to fix this common leaking problem. I found this website helpful regardless(and will use it as a reference if I ever do have to remove my injection pump), and would like to share my experience with repairing the same leak at the Delivery Valve Retainer, that seems to be somewhat common. I am currently cruising and was very motivated to find a way to resolve the leak without potentially crippling my engine for any length of time, and I found it was possible..below is what I did(written in reply to same issue on Cruisers Forum).

I have a Yanmar 3GM30F, and all you have to do to fix the leak that many experience from the top of the high pressure injector fuel pump, is to change out a rubber O-ring. Check out figure #43 on page 52 of this document https://j109.org/docs/Yanmar-3GM30-parts-catalog.pdf

Part #13 is called the "Delivery valve O-ring", it is the only part you need to change. Yanmar part #124550-51370. Or just go match it at a hardware store like I did. The Delivery valve retainer (part #12 on the document I linked to) needs to be cleaned after you get the old, brittle O-ring off, and mine had mild corrosion where the O-ring seats. You can see that there is a bit of design defect here, which causes this leaking problem...just looking at the top of your injection pump, where the leak is coming from, you can see that some of the fuel pools in the recessed area right below the Delivery valve retainer...I think that saltwater spray that got on my engine pooled here, eventually caused the corrosion that made the brittle O-ring not seat so well. But that's a novice theory.

What I can say for sure, is that all you need to do is change the rubber O-ring, no need to mess with the copper gaskets. I was able to replace all 3 O-rings by starting at the forward Delivery valve retainer, removing it, and working my way back. I removed a soft coolant pipe that was in my way of getting the back/last Delivery valve retainer. Obviously, remove all the cooling hoses, clean the area well(spray bottle of soap followed by fresh water rinse, repeat a few times. Dry everything.) Then start removing the delivery valve retainers. I had 2 17mm wrenches and 2 19mm wrenches, and the minor differences in the brand/manufacture of each wrench gives you a few more options to slip a wrench on when you don't have much room/angle to torque with. Keep everything super clean as you remove parts. Pinch off the fuel inlet and outlet soft lines before starting. The springs won't "spring" out at you as you remove the delivery valve retainers, but make sure not to drop them in the bilge. The copper washer and the spring basically seat themselves as you reinstall the Delivery valve retainer, don't worry to much about that. KEEP EVERYTHING CLEAN. Dab the O-ring with diesel before reinstalling the Delivery Valve retainer. There are torque specs I saw online somewhere, mine were on pretty tight and I reinstalled them pretty tight. I cleaned the hell out of the delivery valve retainers, on the portion that the O-ring seats. Everything is back together and the engine runs fine and I have no leaks.