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10-27-2021, 07:09 PM
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#1
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Senior Member
City: Canadensis
Vessel Name: Last Hurrah
Vessel Model: Ta Chiao/CT35 Sun Deck
Join Date: Apr 2021
Posts: 208
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What is this on my Lehman?
Can anyone tell what function this serves?
This is a tap off the rear of the Lehman.
The hose runs to this pump. The pump has an on/off rocker switch to the left.
The pump then connects to these filters.
Thanks,
Bruce
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10-27-2021, 07:19 PM
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#2
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Guru
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 12,818
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I'm not a Lehman expert, but the 1st picture looks like the mechanical fuel pump. The other pump might be to prime the filters and / or be a backup to the mechanical fuel pump. Following the hoses should give you the fuel direction and path.
Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
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10-27-2021, 07:28 PM
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#3
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Senior Member
City: Canadensis
Vessel Name: Last Hurrah
Vessel Model: Ta Chiao/CT35 Sun Deck
Join Date: Apr 2021
Posts: 208
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The hose runs from the engine to the pump then to the filters. I had assumed that the direction of flow was from the engine.
Bruce
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10-27-2021, 07:55 PM
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#4
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Guru
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,119
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Ford Lehman mechanical (lift) fuel pump
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10-27-2021, 07:55 PM
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#5
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Guru
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 12,818
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Assuming the first picture is the fuel pump, where does the other hose go to? The injector pump?
Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
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10-27-2021, 08:04 PM
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#6
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Guru
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,119
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The little hose (maybe metal pipe) out the top foes to the secondary filters which are usually right above it.
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10-27-2021, 08:06 PM
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#7
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Guru
City: Fort Myers, FL... Summers in the Great Lakes
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 12,818
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Maybe someone mounted the secondary filters on the wall.
Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
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10-27-2021, 08:11 PM
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#8
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Senior Member
City: Canadensis
Vessel Name: Last Hurrah
Vessel Model: Ta Chiao/CT35 Sun Deck
Join Date: Apr 2021
Posts: 208
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Two votes for it being a fuel pump. Your picture shows a much more robust fuel hose then mine.
Is the mechanical fuel pump drawing fuel from the filters on the bulkhead and feeding the injectors? If so, what is the purpose of the switched pump on the bulkhead?
I have lot to learn about the fuel system on this boat. It has two fuel tanks and a "day" tank.
I appreciate the input.
Thanks,
Bruce
Quote:
Originally Posted by psneeld
Ford Lehman mechanical (lift) fuel pump
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10-27-2021, 08:19 PM
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#9
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Guru
City: Boston
Vessel Name: Adelante
Vessel Model: IG 30
Join Date: Nov 2016
Posts: 1,608
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The first picture is the mechanical fuel pump. The lower hose comes from the tank manifold. The upper hose originally went to the dual primary/secondary filters mounted on the engine. A previous owner has modified the filters and top hose probably goes to the Racor primary filter now mounted on the aft bulkhead. Then to the secondary filter, and finally to the high pressure injector pump.
PO has also installed a switched electric fuel pump that is apparently used to prime the primary/secondary filters but a wider view photo would be necessary to figure out what PO has done. As mentioned it could be also be used as a backup pump or as a fuel polisher depending upon valve settings and hose arrangement.
The mechanical fuel pump should last forever, it's a $25 part. Failure mode is typically a leaky diaphragm, a $5 part. Electric fuel pumps also last forever. Failure mode is typically corroded connections. Inspect every inch of hoses with LED light and mirror. Replace if tiny cracks are visible.
Fuel can come from one or both tanks depending upon valve setting. Make sure the return valve is set the same way.
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10-27-2021, 08:49 PM
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#10
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Senior Member
City: Canadensis
Vessel Name: Last Hurrah
Vessel Model: Ta Chiao/CT35 Sun Deck
Join Date: Apr 2021
Posts: 208
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There is also a set of filters mounted on the engine near the top of the block. Next time I visit the boat I will check to see if they are plumbed into the fuel system.
Quote:
Originally Posted by SoWhat
The first picture is the mechanical fuel pump. The lower hose comes from the tank manifold. The upper hose originally went to the dual primary/secondary filters mounted on the engine. A previous owner has modified the filters and top hose probably goes to the Racor primary filter now mounted on the aft bulkhead. Then to the secondary filter, and finally to the high pressure injector pump.
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What area should i photo?
Quote:
Originally Posted by SoWhat
but a wider view photo would be necessary to figure out what PO has done.
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Thanks,
Bruce
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10-28-2021, 07:21 AM
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#11
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Guru
City: Edgewater, MD
Vessel Name: Catalina Jack
Vessel Model: Defever 44
Join Date: Nov 2011
Posts: 3,585
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Quote:
Originally Posted by SoWhat
The first picture is the mechanical fuel pump. The lower hose comes from the tank manifold. The upper hose originally went to the dual primary/secondary filters mounted on the engine. A previous owner has modified the filters and top hose probably goes to the Racor primary filter now mounted on the aft bulkhead. Then to the secondary filter, and finally to the high pressure injector pump.
PO has also installed a switched electric fuel pump that is apparently used to prime the primary/secondary filters but a wider view photo would be necessary to figure out what PO has done. As mentioned it could be also be used as a backup pump or as a fuel polisher depending upon valve settings and hose arrangement.
The mechanical fuel pump should last forever, it's a $25 part. Failure mode is typically a leaky diaphragm, a $5 part. Electric fuel pumps also last forever. Failure mode is typically corroded connections. Inspect every inch of hoses with LED light and mirror. Replace if tiny cracks are visible.
Fuel can come from one or both tanks depending upon valve setting. Make sure the return valve is set the same way.
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Yes, the mechanical pumps do last a long time but when that diaphragm fractures, the risk is an oil sump filled with diesel fuel which will wipe the bearings in short order. That is a risk I was not willing to take. I installed a Walbro electric pump, rated for 18,000 hours of use, and removed the mechanical pump. The port in the block can be covered with a Big Block Chevy block-off plate, on-line for about $8.
Side benefit - priming on-engine filters with ease.
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10-28-2021, 08:03 AM
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#12
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Guru
City: Owings, Md
Vessel Name: Graceland
Vessel Model: Mainship 34 MK1
Join Date: Jan 2016
Posts: 1,380
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On some old school mechanical engines (non-common rail), the engines idle smoother when an electric fuel pump is plumbed into the system, providing a more consistent pressure to the injector pump. To my knowledge, most of these pumps will allow fuel to pass through them just fine when not energized, so you don't have to use them all the time, they can be reserved only for priming the filters or whenever you see fit. Someone fitted one to my perkins that is controlled by the oil pressure sensor, this turns it off when the engine isn't running, otherwise it might keep pumping if the key is left on.
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10-28-2021, 09:19 AM
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#13
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Guru
City: Gulf Islands, BC Canada
Vessel Name: Sea Sanctuary
Vessel Model: Bayliner 4588
Join Date: Jul 2019
Posts: 4,993
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Quote:
Originally Posted by catalinajack
Yes, the mechanical pumps do last a long time but when that diaphragm fractures, the risk is an oil sump filled with diesel fuel which will wipe the bearings in short order. That is a risk I was not willing to take. I installed a Walbro electric pump, rated for 18,000 hours of use, and removed the mechanical pump. The port in the block can be covered with a Big Block Chevy block-off plate, on-line for about $8.
Side benefit - priming on-engine filters with ease.
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Since the pump failed how does the sump fill with diesel. Siphoning from the tank if fuel is above pump. did not think membrane failure opens it to spill into block. I thought there was a weep hole at bottom to indicate failure.
__________________
SteveK
You only need one working engine. That is why I have two.
Sea Sanctuary-new to me 1992 Bayliner 4588
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10-28-2021, 11:54 AM
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#14
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Guru
City: Gibsons, B.C., Canada
Vessel Name: Island Pride
Vessel Model: Palmer 32'
Join Date: Oct 2007
Posts: 4,409
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Weep hole or not they can dump fuel into the oil sump.
My BIL had this very problem.
It may well have been a siphon but regardless the source of the fuel was a failed mechanical pump. A new pump stopped the fuel entry.
This is not a new problem for these engines.
There are other sources such as a cracked or loose fuel return line under the valve cover.
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10-28-2021, 11:59 AM
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#15
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Guru
City: Gulf Islands, BC Canada
Vessel Name: Sea Sanctuary
Vessel Model: Bayliner 4588
Join Date: Jul 2019
Posts: 4,993
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Quote:
Originally Posted by C lectric
Weep hole or not they can dump fuel into the oil sump.
My BIL had this very problem.
It may well have been a siphon but regardless the source of the fuel was a failed mechanical pump. A new pump stopped the fuel entry.
This is not a new problem for these engines.
There are other sources such as a cracked or loose fuel return line under the valve cover.
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This is a concern I have not had...... Until now. Thanks
__________________
SteveK
You only need one working engine. That is why I have two.
Sea Sanctuary-new to me 1992 Bayliner 4588
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10-28-2021, 01:03 PM
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#16
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TF Site Team
City: Saltspring Island
Vessel Name: Retreat
Vessel Model: C&L 44
Join Date: Nov 2007
Posts: 5,656
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Quote:
Originally Posted by PennBruce
Your picture shows a much more robust fuel hose then mine.
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I bought fuel hose from a hose store. the only 1/4" ID diesel hose they had was fat like that on the outside. I asked for something a little slimmer (less expensive) and learned that they only sell the fat stuff, as it is fire rated.
__________________
Keith
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10-28-2021, 01:49 PM
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#17
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Guru
Join Date: Jun 2008
Posts: 5,034
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Electric fuel pump for priming, fuel polishing, or as a backup to the mechanical pump.
I only used mine for priming but it was ready for the other tasks if need be.
__________________
Jay Leonard
Ex boats: 1983 40 Albin trunk cabin, 1978 Mainship 34 Model 1
New Port Richey, Fl
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10-28-2021, 02:50 PM
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#18
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Guru
City: Cape May, NJ
Vessel Name: Irish Lady
Vessel Model: Monk 36
Join Date: Dec 2007
Posts: 4,947
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Looks like fuel comes from the fuel tank (assumption), through a large single Racor, then over to the engine mechanical fuel pump, then through the bulkhead mounted black electric fuel pump in series with the mechanical pump, then over to dual secondary Racor filters with metal bowls, then back to the engine.
Then again there are a lot of valves over by the dual Racors that need to be traced out. Start at the tanks and follow the path to the injection pump. There are some labels hanging off the hoses.
__________________
Archie
Irish Lady
1984 Monk 36 Hull #46
Currently in Cape May, NJ
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10-29-2021, 06:48 AM
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#19
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Guru
City: Edgewater, MD
Vessel Name: Catalina Jack
Vessel Model: Defever 44
Join Date: Nov 2011
Posts: 3,585
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Quote:
Originally Posted by Soo-Valley
Since the pump failed how does the sump fill with diesel. Siphoning from the tank if fuel is above pump. did not think membrane failure opens it to spill into block. I thought there was a weep hole at bottom to indicate failure.
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Because a partial tear can continue to supply enough fuel to keep the engine running while still putting fuel into the oil sump.
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11-01-2021, 02:00 PM
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#20
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Member
Join Date: Mar 2010
Posts: 7
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Fuel polishing?
Quote:
Originally Posted by PennBruce
Can anyone tell what function this serves?
This is a tap off the rear of the Lehman.
Attachment 122503
The hose runs to this pump. The pump has an on/off rocker switch to the left.
Attachment 122500
The pump then connects to these filters.
Attachment 122501
Thanks,
Bruce
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Looks like it may be a homemade fuel polishing system system. The other purpose could be a fuel bleeding system that uses the rlectric pump rather than the mechanical lift pump.
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