Bukh DV20 lift pump

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frderek

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This is going to sound really stupid, but here goes.

I'm changing the filters etc. on my Bukh DV20 engine.

I have:

1. Done the RYA Diesel course
2. Bought Paul Manley's Simple Boat Maintenance
3. Searched the web extensively

but am still stuck.

AIUI after I change the fine fuel filter I need to manually activate the lift pump to bleed the fuel through.

Problem: I can't seem to find a lever to do that. Granted the pump is pretty hard up against the side of the engine-bay but given an inspection lamp, a mirror and a lot of feeling around, I STILL CAN'T FIND ANYTHING RESEMBLING A LEVER TO ACTUATE THE PUMP. Help!

many tia

Derek
 
Try turning the engine over, decompressed, a quarter turn or so with the starting handle. Then have another feel for the lever. You put your fingers underneath it and lift it vertically.
 
I have changed the engine-mounted fuel filter quite a few times and have never needed to prime using the lift-pump lever. My tank position is such that the fuel will usually gravity feed anyway. Operating the lift pump manually (to bleed the fuel filter) is only likely to be necessary if your fuel tank is below the level of the engine.
 
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This is a photo of a BUKH lift pump, viewed from aft.

The lever on then left is the priming lever.

http://www.boatpartsandspares.co.uk...ages/bukh-dv10-fuel-lift-pump-dv20-2170-p.jpg

The photo shows an early type of pump, which can be dismantled for cleaning and repair (if you can get the parts). Later models are sealed units but they still have the priming lever in the same place.

If you find the lever and it doesn't seem to do anything, that will be because the lever on the right of the picture (which you won't see because it is operated by a cam inside the engine) has been lifted by the cam. In that case, as James Calvert says, turn the engine over a quarter turn so that the internal lever is no longer being lifted by the cam, and try again. When you lift the priming lever you should feel some resistance when you lift it as it pumps the fuel. On my boat you can hear excess fuel being pumped back into the tank.
 
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Thanks for all the replies. Been back to the boat today and can report that my lift pump looks nothing like the photos. Definitely a completely different pump and I still can't find a manual actuator :)
 
frderek said:
This is going to sound really stupid, but here goes.

I'm changing the filters etc. on my Bukh DV20 engine.

I have:

1. Done the RYA Diesel course
2. Bought Paul Manley's Simple Boat Maintenance
3. Searched the web extensively

but am still stuck.

AIUI after I change the fine fuel filter I need to manually activate the lift pump to bleed the fuel through.

Problem: I can't seem to find a lever to do that. Granted the pump is pretty hard up against the side of the engine-bay but given an inspection lamp, a mirror and a lot of feeling around, I STILL CAN'T FIND ANYTHING RESEMBLING A LEVER TO ACTUATE THE PUMP. Help!

many tia

Derek
Click to expand...

Hope you cleaned the wee nylon filter inside the lift pump. If neglected it can create obscure problems ;-)
 
frderek said:
Thanks for all the replies. Been back to the boat today and can report that my lift pump looks nothing like the photos. Definitely a completely different pump and I still can't find a manual actuator :)
Click to expand...

Well I did say that my photo shows an early type of lift pump. Of course, there's always the possibility (unlikely) that the lever on your pump has been removed or fallen off.

Best thing to do might be to take the pump off (it's only held on with couple of nuts (13mm a/f I think)) photograph it and post the photo on here.

Or you could phone Al Pearson at BUKH Diesel Ltd and ask him.

Or you could prime the system by turning the engine over with the starting handle and the decompressor engaged (not forgetting to shut the cooling water seacock while you do it).
 
parsifal said:
Well I did say that my photo shows an early type of lift pump. Of course, there's always the possibility (unlikely) that the lever on your pump has been removed or fallen off.

Best thing to do might be to take the pump off (it's only held on with couple of nuts (13mm a/f I think)) photograph it and post the photo on here.

Or you could phone Al Pearson at BUKH Diesel Ltd and ask him.

Or you could prime the system by turning the engine over with the starting handle and the decompressor engaged (not forgetting to shut the cooling water seacock while you do it).
Click to expand...

I'm beginning to think the removed/fallen off scenario is very likely! Problem is that it's very inaccessible. Next time I'll take the camera and try to get a look that way.
As the tank is well above the engine I'm hoping that I can bleed it without pumping. Failing that, winding with the starting handle should work - the boat's on the quay so no worries about the sea-cock. Thanks :)
 
Thanks for those recommendations.

Was at a fitting-out supper with the previous owner last night. Turns out there never has been a manual actuator on the pump! Mark, too, spend a while scratching his head about it before ringing Bukh for a definitive answer. At least it means I can forget about it and carry on bleeding by gravity. Ah well....
 
Rhumlady, did Bukh really advise throwing away the filter in the top of the lift pump? Perhaps that's something I could try. My lift pump is sweating ever so slightly, and I suspect the top plate and filter beneath to be part of the problem.

Would appreciate your thoughts?

Paul
 
Pmason said:
Rhumlady, did Bukh really advise throwing away the filter in the top of the lift pump? Perhaps that's something I could try. My lift pump is sweating ever so slightly, and I suspect the top plate and filter beneath to be part of the problem.

Would appreciate your thoughts?

Paul
Click to expand...
Sorry to butt in - but I had similar slight weeping from my Bukh lift pump - and this after I had bought it a refurb kit. After a lot of investigation and additional (not needed) replacements I found the leaking was my own fault. I had overtightened the screws holding the pump chamber to the body with the diaphragm in between. I had distorted the flanges so that they wouldn't seal properly. I had to dismantle the pump and carefully grind the mating flanges flat again and then reassemble, using only enough torque to achieve a seal. You haven't been tightening up those screws, have you?
 
Hello Neil:
Your butting in is most welcome! As a matter of fact a couple of years ago I did remove the top and rinse out the filter as per the manual. It’s perfectly possible that I overtightened it. I’ll investigate that.
So, when I do, should I remove the filter altogether?
Paul
 
Pmason said:
Hello Neil:
Your butting in is most welcome! As a matter of fact a couple of years ago I did remove the top and rinse out the filter as per the manual. It’s perfectly possible that I overtightened it. I’ll investigate that.
So, when I do, should I remove the filter altogether?
Paul
Click to expand...
I don't know your configuration but throwing away a filter is rarely a good idea. Assuming that the pump is between the primary and secondary filters (and the mesh is relatively coarse) then it shouldn't have any material blocking it anyway. If there is crud passing through the primary filter and blocking the mesh then clean the mesh and fix the source of the crud, if you have no primary filter then fit one. Throwing the mesh away means one less unit of protection for the (expensive) fuel pump.
 
I reassembled my lift pump with all it's components and after repairing the flanges it has not given any more trouble. Indeed - I have fitted a CAV fuel filter with a 10 micron element near the fuel tank and now do not interfere with any of the fuel components on the engine at all. Seems to me that not tampering is the best way to keep the system clean!
 
My pre-lift pump filter is 2 microns. I presume that if Bukh did indeed suggest removing the diaphragm inside the lift pump to someone, it would be because 1) It isn't doing anything useful and 2) It does potentially cause a problem with the seal when you reassemble the pump. I would not have reefed down on those screws, but I do recall some minor difficulty getting the diaphragm to fit back in properly. I will check it carefully. Thanks everyone for your input.

BTW I have also looked into replacing the pump with a newer version, and that newer version does not appear to have a diaphragm - at least not one that is accessible for cleaning.

Paul
 
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