Fuel Pump Fail?

Jim Hardesty · June 15, 2025, 12:27:29 PM

QuoteAlso, no extension hose on my pickup. Do I need this?

Measure it. Should come to about 3/8 to 1/2 inch from bottom of the tank to the high point of the notch at the bottom of the pick up.
Jim

KWKloeber · June 15, 2025, 04:04:36 PM

Quote from: rjabara on June 12, 2025, 06:54:54 PMWell, fuel pump replaced but did not resolve the problem.

If any other thoughts, I'll take them

Hence, what I have said on here way, way too many times.

Do NOT play Whack-a-Mole and start replacing parts Willy-nilly.

It can get frustrating, waste valuable maintenance/repair/sailing time, unnecessarily consume boat bucks, diverts good beer (or other alcohol) money, and can lead to sleepless nights asking the question, "Was that the root cause, or a coincidence" (it is a boat after all.)

troubleshoot - Troubleshoot - TROUBLESHOOT.
Then, start replacing parts willy-nilly.

Isolate and test (or bypass) a suspected bad part if possible.

KWKloeber · June 15, 2025, 06:48:56 PM

QuoteI think M35 is self bleeding but I bled anyway.

I have opined many times that anyone with a Universal that doesn't have the knurled bleed knob (such as an M-25) should install it. And anyone who has the knob as OEM (such as an XP) should replumb the fuel flow (as I did) so that the knob does not return the bled fuel to the tank.

This makes troubleshooting more straightforward and allows viewing the fuel flow/condition while bleeding. The OEM setup prevents that, which, for Kubota to have done that, was, using a technical term, plain stupid.

If one wants to retain the option of returning fuel to the tank, that can also be accomplished.

rjabara · June 17, 2025, 08:33:15 PM

The good news is that I am back up and running. Thank you all for your input. The bad news is that I am not EXACTLY sure why, lol.

I started at the tank with the pickup, then to the Racor (changed to new), the pump (new), then to the secondary filter. When I pulled the hose and ran the pump, it dumped some debris in the container that I was using. I don't know how this got through the racor but there it was. I changed the secondary filter, reconnected everything, ran the pump for a bit to bleed and after a few tries, she started right up. Ran for 20 minutes at idle, at 2000, and in and out of gear. Sounded better than ever and started up faster than ever. Upon changing the secondary filter, I noticed that that bracket was completely broken (discussed at some length on this forum many times). In reading past forum entries, these brackets from Westebeke went from being free, to $22.00 to now $65 + shipping. That is some inflation.

Thanks again!

KWKloeber · June 18, 2025, 08:53:57 PM

Rich

Be aware that even the "new, improved" Westerbeke bracket can fail with a crack at the gentle radius rather than the sharp bend.

Ron Hill · June 19, 2025, 01:48:48 PM

Rich : With all that was said the junk was the stoppage!!

FYI the engine will run without the fuel pump because the fuel will gravity flow - fuel tank is higher than the engine!!

A thought

rjabara · June 19, 2025, 07:13:56 PM

Ron, it seems that way. I am getting better at troubleshooting with all of your help, but clearly a long way to go.

I just couldn't get through my head how that junk could get through my (new)racor 10 and end up clogging the end of the hose to secondary filter.

rjabara · July 28, 2025, 08:05:33 PM

Picking up on an old post of mine, I finally ordered and received the bracket as pictured by Ken above. I think it is the wrong bracket as my old one was not offset like this new one. I think I can still get it to work but I need to lengthen the fuel hose connecting the internal filter to the injector. Does anyone know the replacement spec of that hose and any issues I should be aware of when changing that out?

Also, how does the silencer open so that I can install the new air filter? I unscrewed the top but doesn't seem to want to open.

Thank you.

KWKloeber · July 28, 2025, 11:54:18 PM

There were two different silencers used.
Pictures, pictures, pictures.

rjabara · July 29, 2025, 06:41:54 AM

Here it is

Ron Hill · July 29, 2025, 02:40:05 PM

rja : If my fuel pump bracket had a crack - I would have taken it to a local welder for repair!!

A thought

dfloeter · July 30, 2025, 08:24:29 AM

A question for Ken on the fuel return or not comment. Mine does funnel the overflow to the tank and I did not know there was an option. Does the excess fuel stay before the high pressure pump and is used as necessary? This is a mystery. How is the alternative an improvement? I don't mean this as criticism and just wish to understand.

KWKloeber · July 30, 2025, 12:18:24 PM

Quote from: dfloeter on July 30, 2025, 08:24:29 AMA question for Ken on the fuel return or not comment. Mine does funnel the overflow to the tank and I did not know there was an option. Does the excess fuel stay before the high pressure pump and is used as necessary? This is a mystery. How is the alternative an improvement? I don't mean this as criticism and just wish to understand.

Dietrich

On the later engines, the barb on the bleed knob feeds a hose that runs to the Injector Banjos, and to the hose barb fitting that has the fuel return hose to the tank.

So the bled fuel "mingles with" the excess fuel that collects from the Injectors via the banjos and returns to the tank. The bled fuel doesn't remain before the injector pump because that would counteract against bleeding air out of the system if it remained in the supply to the pump.

I describe it here:
https://groups.io/g/Catalina30/message/105848

The benefit
https://groups.io/g/Catalina30/message/105848
is being to actually SEE the fuel condition and what's going when troubleshooting the system. We can't see any of that how Kubota instaoloed the fuel bleed knob on the D950 with bled fuel returned to the tank.

If one desires, a small brass inline valve could be added to allow either option.

(Ignore that the fuel hose is disconnected from my secondary filter housing) the bled fuel simply exits the barb on the bleed knob (into a plastic Solo cup.)

dfloeter · July 31, 2025, 02:06:24 PM

Thanks Ken for a very good diesel fuel system lesson and I think I get it now. The missing part for me was the disconnection of the bleeder tube as you have done and run it into a clean cup. Mystery solved.

KWKloeber · August 01, 2025, 12:24:20 PM

Dietrich

In your quest for understanding let me be precise about how this evolved. I didn't disconnect a hose — there never was one.

The early M-25s had a hex-head bleed bolt like the D850 engine below. Open the bolt like 1/2 turn and diesel shoots out a hole in the side of the hex head. So long as you're quick, have rags down, and a cup ready it was ok. Mess up, and you get a messy engine.

The knob w/ its hose barb simple replaced the hex bolt assembly. It's good that there was no hose because I would have left it as-is when adding the knob valve. AND never would have experienced (IMO) the joy when I see the bleed!

Late-model M-25s switched to the knob.