Fuel pump assy - A few questions.....

spenny_b

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Morning chaps,

Well, a strong smell of fuel the other day has led me to another "while I'm at it" project. A leaking black "out" QR coupling, that could've probably been easily solved with a couple of Viton o-ring swaps, has turned into me stripping down the fuel pump assembly to install new CPC metal coupling from Tom Parker. Helpful folks there (as everyone says) but I think I may need to be testing their helpfulness one more time on Monday. They don't stock the NPT thread sockets that install into the pump plate, only BSPT, so they suggested some NPT>BSPT adapters. This adds stack height, and now I've assembled them, I struggle to believe it'll clear the engine. Won't know for sure until pump is back in the tank, we'll see...

Anyway, that wasn't the reason for posting.

What I've found along the way is that there was no pre-pump filter; the baffle for the pump is circlipped in place, and the pump has the full rubber sleeve. When I pulled the pump from the housing, nothing is there below it. The "separator hose" was just dangling, whereas it should be attached to the pre-filter.

I received the kit of bits this morning, and when trying to mate filter to pump, there's no obvious engagement; I can see where it sits in the metal housing, there's a recess for the separator hose nipple....but my best guess suggests the pump just butts up against it, when pushed into the metal housing, using the rubber sleeve to kind of seal to the filter...is this correct?

IMG_2423 2.jpg
IMG_2424 2.jpg
IMG_2425 2.jpg


Second question/observation......when draining the tank and letting it dry, there was a "desert beige" coating on the bottom....and also on the entire fuel pump assembly. Even gentle handling of the pump was wiping it off, so I can't believe it was meant to be there (i.e., a sprayed on protective coating).....same goes for the tank, gently wiping it and it's just falling off....now looks like bloody sand in the tank!!

IMG_2421.jpg
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So, clearly a thorough clean up is going to be done, hoover it all out and use a selection of brushes to get every nook and cranny. The curved surface of the tank has a satin black finish, but the base will now be bare metal.

Question, was this some kind of factory coating that's now failed, or have I really got a load of shite in the tank (and with no pre-pump filter installed.....er.....). Next question....do I now need to use some kind of tank sealant to protect the bare metal, or is it zinc plated (for example)?

Thanks in advance chaps, appreciate the guidance as always.

S
 

West Cork Paul

Elite Member
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Firstly, the beige sand - its fuel sludge deposits, not a lining in the tank, so just clean them out. The tank should be sprayed black inside, there’s no need IMO for you to re-coat it.

Re the pre-filter, the photo below is from the pump on my 998, so identical design, it doesn’t have the massive rubber washer yours does. Sorry it’s a bit blurry. Can you remove the rubber washer and then see if the pre-filter fits?
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072A214F-9E99-4492-A3E3-75BA432F90FF.jpeg
 

Markduc

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That's exactly what my tank internals look like .....

Not wanting to hijack the thread here , but that plug thingy ( right in the middle of the flange ) has baffled me for years .

Does anyone know what the hell it is there for ?
Summation to do with the Pressure relief valve ?
 

spenny_b

Member
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That's exactly what my tank internals look like .....

Not wanting to hijack the thread here , but that plug thingy ( right in the middle of the flange ) has baffled me for years .

Does anyone know what the hell it is there for ?
Yep, as Markduc says, it's part of the machining for the feed to the fuel pressure regulator valve. That hex screw unscrews easily enough and allows you to clean it out (which I did), then reseal with a copper washer and threadlock.
ive bought 1/4 npt QR from them in both straight and 90 degree female to male...
Yes, I have to confess I was slightly scratching-of-head when he said (very confidently) that they didn't sell the NPT versions. Perhaps it's a discontinued line?

I checked the setup I have with the adapters, and f***ing typical, it doesn't clear.....just....the fuel feed at the front clears nicely, but the return feed just nibs the top of the cam cover. Although the tank does screw down correctly, you can just hear a metal>metal knock, and a blutak check confirms.

Two choices now, buy two more fekking sockets (thanks for the 'grab Andy) or do I buy a 1/4" NPT die and machine down the taper on the adapter, and get it sitting closer to the pump plate.....(another) £50 for more fittings or £7.40 for a die from the 'Bay + some machining effort (which I'm more than ok with doing)....I hear a beer calling....

Firstly, the beige sand - its fuel sludge deposits, not a lining in the tank, so just clean them out. The tank should be sprayed black inside, there’s no need IMO for you to re-coat it.

Re the pre-filter, the photo below is from the pump on my 998, so identical design, it doesn’t have the massive rubber washer yours does. Sorry it’s a bit blurry. Can you remove the rubber washer and then see if the pre-filter fits?
View attachment 24523View attachment 24524

Thanks Paul, very reassuring about the tank and fuel deposits. I'll give a right old going-over with tooth brushes etc before reassembly.

Re the pump sleeve, the thick rubber "washer" at the bottom of my sleeve - I think - is integrated with the whole thing. Not to say it can't be cut off though. I'll check the parts diagrams and see if the 2001 748R used a different pump/sleeve.

Will keep you posted!

Thanks again everyone, really helpful.
 

spenny_b

Member
Subscriber
I wonder if the answer I got from Tom Palmer yesterday was to do with them not selling a Viton sealed NPT socket? Looking at the part you screen-grabbed for me, CPC have used Buna N as the seal material, not Viton.

However.....a quick Google on Buna N shows that it's resistant to petroleum based fuels as well....


....so I'm not sure whether this Viton requirement is actually a red herring, and Buna N is just fine?
 

Noobie

Elite Member
Subscriber
These are from the states, would they do?

Ducati Chrome Plated Brass Metal Gas Tank Fuel Pump Quick Release NPT Disconnect Set: 748-998, MV Agusta F4 750/1000, Triumph 58840091A 58840101A 58840111A 58840121A


 

West Cork Paul

Elite Member
Subscriber
I wonder if the answer I got from Tom Palmer yesterday was to do with them not selling a Viton sealed NPT socket? Looking at the part you screen-grabbed for me, CPC have used Buna N as the seal material, not Viton.

However.....a quick Google on Buna N shows that it's resistant to petroleum based fuels as well....


....so I'm not sure whether this Viton requirement is actually a red herring, and Buna N is just fine?
Viton is a trademark of DuPont. Buna-n is a nitrile compound (as is Viton) they are both oil and petroleum resistant 👍
 

West Cork Paul

Elite Member
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I'll check the parts diagrams and see if the 2001 748R used a different pump/sleeve.
Just checked, there’s no rubber washer there

61460B30-284D-408B-884E-C31A2BCF5F7F.png

2002 748R

Tbh there’s no reason why the assembly for the 748R would be any different from any other bike in that range - the R bits are in engine, chassis and suspension.
 

spenny_b

Member
Subscriber
Cheers Paul,

Just been back out in the workshop and had another play (was a bit rushed this morning). Sussed it....For anyone else searching this in future and doing it for the first time like me.....slide the boot right down the pump, past the baffle, then pop the filter onto (what I thought was) the washer-type-thing, with the correct orientation of outlet pipe and semi-circular cutout, and the gap in the boot vs the notch in the baffle. Washer-type-thing sat in the ID of the filter nicely, then slide both pieces back up the pump. Happy days....

IMG_2428.jpg


....then re-install back into the assembly and connect the separator hose....

IMG_2429.jpg


New inline filter installed as well, and she's ready to go back in.

The date stamp on the inline filter is Feb 2020, so it was done by the Ducati dealer relatively close to me as part of the fuel line replacement (before I bought the bike). Clearly refitting a pre-pump filter didn't interest them, along with mis-installing the injection bodies into the rubber sleeves (so that they popped out mid ride, leaving me with a very rough running bike to limp back home. The vertical cylinder trumpet wasn't pushed "home" into the indent of the rubber sleeve, so when the jubilee clip was done up, all it did was squeeze the taper and pop it out under vibration....FFS). Think I'll be giving these guys a miss when it comes to the valve clearance checks, I'll make the effort and van it to Moto Rapido or Ducati Coventry I think [tut].
 

West Cork Paul

Elite Member
Subscriber
Cheers Paul,

Just been back out in the workshop and had another play (was a bit rushed this morning). Sussed it....For anyone else searching this in future and doing it for the first time like me.....slide the boot right down the pump, past the baffle, then pop the filter onto (what I thought was) the washer-type-thing, with the correct orientation of outlet pipe and semi-circular cutout, and the gap in the boot vs the notch in the baffle. Washer-type-thing sat in the ID of the filter nicely, then slide both pieces back up the pump. Happy days....

View attachment 24561

....then re-install back into the assembly and connect the separator hose....

View attachment 24562

New inline filter installed as well, and she's ready to go back in.

The date stamp on the inline filter is Feb 2020, so it was done by the Ducati dealer relatively close to me as part of the fuel line replacement (before I bought the bike). Clearly refitting a pre-pump filter didn't interest them, along with mis-installing the injection bodies into the rubber sleeves (so that they popped out mid ride, leaving me with a very rough running bike to limp back home. The vertical cylinder trumpet wasn't pushed "home" into the indent of the rubber sleeve, so when the jubilee clip was done up, all it did was squeeze the taper and pop it out under vibration....FFS). Think I'll be giving these guys a miss when it comes to the valve clearance checks, I'll make the effort and van it to Moto Rapido or Ducati Coventry I think [tut].
Glad you got it sorted and useful to know how it’s assembled as that big ‘washer’ doesn’t appear in the parts diagram. Tbh every time I’ve done a fuel filter change I’ve never had reason to separate the prefilter from the pump, merely pulled the pump and checked there’s no gunge on the pre-filter.
 

spenny_b

Member
Subscriber
Just an update on this little project-ette. All back together; annoyingly, I cocked up the installing of the pump assy back into the tank, despite using the retaining screws to pull it in evenly, I clearly hadn't checked that the large o-ring was seated correctly - it must've "jumped" out of the channel it should sit in. I thought something was up when a sudden pop noise happened - that actually turned out to be the o-ring being sliced; a nice 1" long slither being shaved off of it. Arse. A few days later when the second o-ring turned up and I got it installed without any dramas.

I also did buy the correct NPT threaded sockets for the tank side of the fittings, rather than faff about with the adapters I'd bought. End result is that it installs just like factory, but the metal QR fittings are so much nicer, really nice positive engagement.

Finally, after 1200 mile (wet) touring around Wales on the GS over the weekend, I came back to the garage to find absolutely no smell of fuel. Huzzah. A nice 30 mile evening ride out actually revealed something that I read elsewhere - my bike did used to have a significant dead spot lower down the rev range when winding on. Generally more noticeable when the engines warming up....it's now gone, pulls far cleaner now that everything's been cleaned out, and both filters replaced. Even though the inline filter was relatively new, it ain't no good fitting a new filter if you don't first clear out the shite in the tank! (another reason to not use the dealer who did the work before me buying the bike)
 

West Cork Paul

Elite Member
Subscriber
Just an update on this little project-ette. All back together; annoyingly, I cocked up the installing of the pump assy back into the tank, despite using the retaining screws to pull it in evenly, I clearly hadn't checked that the large o-ring was seated correctly - it must've "jumped" out of the channel it should sit in. I thought something was up when a sudden pop noise happened - that actually turned out to be the o-ring being sliced; a nice 1" long slither being shaved off of it. Arse. A few days later when the second o-ring turned up and I got it installed without any dramas.

I also did buy the correct NPT threaded sockets for the tank side of the fittings, rather than faff about with the adapters I'd bought. End result is that it installs just like factory, but the metal QR fittings are so much nicer, really nice positive engagement.

Finally, after 1200 mile (wet) touring around Wales on the GS over the weekend, I came back to the garage to find absolutely no smell of fuel. Huzzah. A nice 30 mile evening ride out actually revealed something that I read elsewhere - my bike did used to have a significant dead spot lower down the rev range when winding on. Generally more noticeable when the engines warming up....it's now gone, pulls far cleaner now that everything's been cleaned out, and both filters replaced. Even though the inline filter was relatively new, it ain't no good fitting a new filter if you don't first clear out the shite in the tank! (another reason to not use the dealer who did the work before me buying the bike)
Good to hear that ?

The exact same thing happened to me with the o-ring the first time so now, whenever I need one I order two, just in case. I’m probably ok for them now as I’ve 2 or 3 spares in the drawer. 😕
 
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