Westerbeke 4-91 Injection Pump Leaking

[sanibel sailor]

Are the bolts thru the housing the only thing retaining the throttle and kill shafts? Looks simple now that it is apart.

[marvinjansen50]

yes, the bolts are the only thing holding the two shafts in. The shafts have a groove all the way around that rotate around the bolt. I bought the whole rebuild kit for $38 but only used 2 o rings, 2 bolt rubber washers, and the gasket, but guess it was worth it. If yours is leaking you could replace these parts yourself. If I was going on a long trip I would have the whole pump rebuilt, but for now this is good for me to make this repair and use it close in Mobile Bay and the intercostal. Would be nice to make it down to Sanibel Island someday, and back home to the St. Pete area too.

[sanibel sailor]

I have the kit but was hesitant to pull the shafts as I did not see how it went together. I learned something new from this. I will probably do this as I have the O-rings from my kit

[marvinjansen50]

Running good now, no leaks!

[sanibel sailor]

congrats

[sanibel sailor]

Just did mine, sure was easy. Mine is slightly different with 2 O-rings on the throttle shaft as well as an extra groove without an O-ring. Did not find matching O-rings in my kit, but I had some on hand that matched. Just need to reinstall.

[marvinjansen50]

John, That is great you got your shaft sealed. I went ahead and put an o ring on the fuel shut off shaft too since it was apart. My seal on the throttle shaft was definitely worn and brittle but the one on the shut off shaft was in good shape, guess got less use. Mine is still doing good and no leaks, just ran it today.

[sanibel sailor]

I did both as well, left the "throttle plunger" in place, so as to not get it out of place and cause a runaway (although my concerns of that are minimal.)

[MDR_Sailing]

Looks like I'm having the same issue on the Westerbeke 30 in my 1978 Cal 34.

Is the general consensus that this can be done while the pump is still attached to the block?

Also, does anyone know of an online retailer to purchase the rebuild kit/appropriate o-rings for this project?

Any help is appreciated!

[marvinjansen50]

If I had to do it again I would pull the shafts out and go to an auto parts store to get orings to match the ones taken out. I would also need some washers for the 2 bolts if the existing ones were not suitable for reuse. Guess some orings would work on the bolts too, I'd try some. I got my complete parts kit from a local fuel injector shop (Test Calibration Company in Mobile, AL, 251-471-3777) for about $40. You can try Ebay for a kit also. I also would probable leave the fuel shut off shaft alone as mine was not leaking and the oring was in good shape. So, all you probable need to do is remove one bolt, slide out the throttle shaft, replace the oring, and put the shaft back in. Keep it simple. Good luck.

[sanibel sailor]

Originally Posted by marvinjansen50

If I had to do it again I would pull the shafts out and go to an auto parts store to get orings to match the ones taken out. I would also need some washers for the 2 bolts if the existing ones were not suitable for reuse. Guess some orings would work on the bolts too, I'd try some. I got my complete parts kit from a local fuel injector shop (Test Calibration Company in Mobile, AL, 251-471-3777) for about $40. You can try Ebay for a kit also. I also would probable leave the fuel shut off shaft alone as mine was not leaking and the oring was in good shape. So, all you probable need to do is remove one bolt, slide out the throttle shaft, replace the oring, and put the shaft back in. Keep it simple. Good luck.

Simple is not a bad way to go, but I would get the whole deal on eBay $17 shipped in case you want to do something else then or later. Plus, it sure is nice to be able to fix it all at the same time while I am slithered down into the hole.

CAV part number is 7135-110, key elements are 4 cylinder rotary pump. The kits I have bought have a whole lot of extra bits, always nice to have, and I know the O rings are meant for diesel.

7135 110 Ford Massey Ferguson CAV DPA Injector Pump Repair Kit 4000 7600 | eBay

[MDR_Sailing]

Thanks for the link John, I went ahead and purchased that kit, just in case I come across anything else that need replacing along the way.

Do either of you have a photo of where the throttle shaft is located on the pump itself (while installed)?

I am having a hard time locating it while contorted under the sink!

I will try to get photos of my pump next time I am down at the boat too.

[marvinjansen50]

Have someone move the throttle from slow to fast and look where the linkage is attached to the pump and you will have it. Are you sure it is leaking? May have a pic somewhere if you still need it.

[sanibel sailor]

Looking at the engine, the throttle housing sits on top of the pump with the throttle to the left and the stop cable to the right.

[MDR_Sailing]

Thanks gentlemen, it looks like I've located it in the photos below. I'm pretty sure that is where the leak is originating, I'm getting a drop of diesel every 10 or so seconds at the lowest point of the pump. All the other fittings/hoses seem dry.

It looks like I have the 12pt bolts instead of the hex head bolts. Do you know which socket I'll need for removal here? I think you mentioned it being a little difficult to find.

Is the o-ring that will need replacing pretty easy to locate once I remove the two bolts and pull the throttle shaft?