Minnimec Delivery Valve Seal Leak - Lehman 120hp

[Scurvy_Dan]

I was unable to find any information on how to repair a diesel fuel leak on my 120hp Ford Lehman. My thirty six year old engine began to leak at the base of Delivery Valve Holders on cylinder #5 and #6. I consider any fuel leak to be a show stopper and was worried this would be the end of our boating season until repairs were made. I did some research and discovered that the service manual states the Delivery Valves can be serviced without removing the Fuel Injection Pump. I called American Diesel to find out if they sold the special tool to remove the Delivery Valve Holders as shown in the service manual. I was told they do not sell the tool and that they do not recommend owners making this repair. I was given the name of some Diesel Injection Pump Repair Shops and started calling around for a price quote on this repair. Every shop I called wanted me to remove the entire pump and send it to them. One shop even told me that they would not repair my leaking pump without also rebuilding my injectors. I was looking at a minimum price quote of $2,000 for a pump rebuild and $100 per injector rebuild - OUCH!!

There are many websites that show people how to make this repair on a leaking Mercedes Benz but nothing on a Minnimec Pump. I knew this was not a complicated repair and would not require my pump to be re-timed or calibrated. I just need to stop the leaking seals. I was able to find an online store that sold the special socket and a rebuild kit for the Minnimec Pump. Believe it or not, they are in France - autodiesel13.com/en - and they ship parts internationally! I was able to purchase the socket (ED0422) for $70 and the gaskets and seals (ED1109111) for $14 and shipping to the US was $35. Everything arrived in less than one week and I was ready to begin fixing the fuel leaks.

Before I began to make this repair I made sure the work area was clean and I added a mat underneath the pump to catch any pieces that may try to run away. I loosened/removed the fuel lines from the injection pump to the injectors just enough to access the Delivery Valve Holders on #5 and #6 (back of the pump). Once the lines were out of the way I placed the caps that were provided in the seal kit on top of each Delivery Valve Holder.

Now it was time to remove the Delivery Valve Guide. Once the guide was out i simply removed the rest of the components in order. If your pump is like mine you will have seven pieces when you are said and done. Do one Delivery Valve at a time and NEVER mix parts! Take great care to keep everything in the exact order it came out so that you put it back together correctly. Here are the photos of my pump during the removal of these seven components.

If you look at the last picture above it has all the components laid out on a mat. From left to right the parts are:

1. O-Ring
2. Delivery Valve Guide
3. Steel Crush Washer
4. Delivery Valve
5. Spring
6. Volume Reducer
7. Delivery Valve Holder

You need to replace #1 and #3 with new components from the gasket and seal kit. Make sure you use the Steel Crush Washers and not the Brass Crush Washers that are in the kit. After you have swapped out these two parts you simply need to reverse the removal process taking care to put everything back together the way you found it. I placed the O-Ring in first followed by the Delivery Valve Guide and the Delivery Valve. After these components were in I placed the Steel Crush Washer in place making sure to keep it centered as best as possible. Then the Spring and Volume Reducer went back in and I re-installed the Delivery Valve Holder. Using a torque wrench each Delivery Valve Holder was torqued to 26 ft/lb.

I repeated the process for the #5 cylinder and re-installed my fuel lines. The Delivery Valve Guide on #5 did have some corrosion were the Steel Crush Washer met it's top surface. I used 320 grit and paper and cleaned it up before reassembly. The entire job took less than two hours but I would plan on 4-6 hours if you were doing all six cylinders. Before I fired up my engine I drained one of my primary fuel filters and filled it up with Hot Shots Diesel Extreme Fuel Detergent & Booster. This may have been unnecessary but since the one shop I called recommended rebuilding my injectors I figured why not? I fired up the engine and after it warmed up I ran it hard for 20 minutes. NO MORE LEAKS!!

A $2,600 dollar repair for $119. Where will I spend the other $2,481? Oops - I forgot the injector cleaner was $10 so there is only $2,471 left. Darn!!

Hope this helps!

 

[Bob Cofer]

This needs to be a sticky.

 

[psneeld]

Nice post...mine have been leaking for the last 2 trips to Florida...maybe a bit more on the last legs home...being a pretty new fuel pump...was waiting for rebuild as most say that's the way to go.


Now I see that it isn't as big a job as some have alluded to.

 

[Scurvy_Dan]

Thank you for the nice replies. This job was not that tough at all. I was expecting to have springs flying every which way but that was not the case. Nothing is under tension after you unscrew the Delivery Valve Guide a few turns.

What was the cause of the leak? I never feel good as a mechanic unless I know the cause of the problem. The answer (at least in my case) - the steel crush rings had corroded enough to let the diesel fuel (under a lot of pressure) leak out and up the thread fittings. With all the vibration I guess it is only a matter of time. Some mechanics suggest using red loctite on the Delivery Valve Guides during re-assembly. I did not do this but it may not be a bad idea.

I was ready to send this pump out to have it rebuilt. When I called around to get some quotes I told the shops it was a Minnimec pump from an Industrial Ford Diesel. When one shop found out it was from a boat they doubled the price and even wanted to know if I was a transient! Guess they wanted to double the price again? That was the final straw for me. I found the parts and did it myself!

Fair Winds,

Captain Dan

 

[psneeld]

Mine for the most part has slowed or stopped once warmed up so I am in no rush...but your post inspired me to go ahead and at least buy the socket.

 

[ddalme]

red locktite?? Hate to have to remove them again. The crush ring should do just find. Nice write up Captain Dan!

 

[Scurvy_Dan]

red locktite?? Hate to have to remove them again.

That is exactly why I did not use it.

;-)

 

[RT Firefly]

Greetings,
Mr. SD. That's a helluva first or second post. Welcome aboard and well done. Thanks.

 

[CPseudonym]

Epic first post and I agree with Bob, this needs to be a sticky thread

 

[Peter B]

Point taken suh..! Totally agree...
Great post.
Now I'm going to have to have a jaundiced look at mine...delivery valve holders, that is. I didn't even know I had some...

 

[Trawler Sandpiper]

Great write up

 

[Martin J]

Great article, Well done..

 

[hmason]

What an inspiration. I'll bet there are many projects that can be done if you just have the nerve to dig in and give it a go. Thanks!

 

[High Wire]

Were the steel crush washers and the brass crush washers in the same kit? If so, what are the brass ones for?
Excellent post!

 

[Forkliftt]

I was unable to find any information on how to repair a diesel fuel leak on my 120hp Ford Lehman. My thirty six year old engine began to leak at the base of Delivery Valve Holders on cylinder #5 and #6. I consider any fuel leak to be a show stopper and was worried this would be the end of our boating season until repairs were made. I did some research and discovered that the service manual states the Delivery Valves can be serviced without removing the Fuel Injection Pump. I called American Diesel to find out if they sold the special tool to remove the Delivery Valve Holders as shown in the service manual. I was told they do not sell the tool and that they do not recommend owners making this repair. I was given the name of some Diesel Injection Pump Repair Shops and started calling around for a price quote on this repair. Every shop I called wanted me to remove the entire pump and send it to them. One shop even told me that they would not repair my leaking pump without also rebuilding my injectors. I was looking at a minimum price quote of $2,000 for a pump rebuild and $100 per injector rebuild - OUCH!!



There are many websites that show people how to make this repair on a leaking Mercedes Benz but nothing on a Minnimec Pump. I knew this was not a complicated repair and would not require my pump to be re-timed or calibrated. I just need to stop the leaking seals. I was able to find an online store that sold the special socket and a rebuild kit for the Minnimec Pump. Believe it or not, they are in France - autodiesel13.com/en - and they ship parts internationally! I was able to purchase the socket (ED0422) for $70 and the gaskets and seals (ED1109111) for $14 and shipping to the US was $35. Everything arrived in less than one week and I was ready to begin fixing the fuel leaks.



Before I began to make this repair I made sure the work area was clean and I added a mat underneath the pump to catch any pieces that may try to run away. I loosened/removed the fuel lines from the injection pump to the injectors just enough to access the Delivery Valve Holders on #5 and #6 (back of the pump). Once the lines were out of the way I placed the caps that were provided in the seal kit on top of each Delivery Valve Holder.

Now it was time to remove the Delivery Valve Guide. Once the guide was out i simply removed the rest of the components in order. If your pump is like mine you will have seven pieces when you are said and done. Do one Delivery Valve at a time and NEVER mix parts! Take great care to keep everything in the exact order it came out so that you put it back together correctly. Here are the photos of my pump during the removal of these seven components.

If you look at the last picture above it has all the components laid out on a mat. From left to right the parts are:

1. O-Ring
   
2. Delivery Valve Guide
   
3. Steel Crush Washer
   
4. Delivery Valve
   
5. Spring
   
6. Volume Reducer
   
7. Delivery Valve Holder
   

You need to replace #1 and #3 with new components from the gasket and seal kit. Make sure you use the Steel Crush Washers and not the Brass Crush Washers that are in the kit. After you have swapped out these two parts you simply need to reverse the removal process taking care to put everything back together the way you found it. I placed the O-Ring in first followed by the Delivery Valve Guide and the Delivery Valve. After these components were in I placed the Steel Crush Washer in place making sure to keep it centered as best as possible. Then the Spring and Volume Reducer went back in and I re-installed the Delivery Valve Holder. Using a torque wrench each Delivery Valve Holder was torqued to 26 ft/lb.



I repeated the process for the #5 cylinder and re-installed my fuel lines. The Delivery Valve Guide on #5 did have some corrosion were the Steel Crush Washer met it's top surface. I used 320 grit and paper and cleaned it up before reassembly. The entire job took less than two hours but I would plan on 4-6 hours if you were doing all six cylinders. Before I fired up my engine I drained one of my primary fuel filters and filled it up with Hot Shots Diesel Extreme Fuel Detergent & Booster. This may have been unnecessary but since the one shop I called recommended rebuilding my injectors I figured why not? I fired up the engine and after it warmed up I ran it hard for 20 minutes. NO MORE LEAKS!!



A $2,600 dollar repair for $119. Where will I spend the other $2,481? Oops - I forgot the injector cleaner was $10 so there is only $2,471 left. Darn!!



Hope this helps!

Scurvey_Dan, that is some priceless information for all running the engine. What a great article! I bet the mods would love to get this accessible to all somewhere it can be located easily.
Welcome aboard!
You might want to consider joining boatdiesel.com too. They are looking for information like this and would probably love to get you to put an article together. Nice job !!


1983 Present 42 Sundeck
Twin Lehman 135's

 

[Scurvy_Dan]

Thanks again to everyone for your kind reviews. I love my Ford Lehman and have searched the internet for information on this repair and others. There is not a lot of organized information out there and that is frustrating. I hope this posts helps my fellow boaters keep their Lehman's running without the fire risk associated with a fuel leak. Before I make any more posts I will introduce myself in the 'Welcome Mat'.

Fair Winds,

Captain Dan

 

[Doug H]

I am seeing fuel around the injector tube where it exits the top of one of the nuts on my Minimec pump. I assumed that it was just a loose nut -- tightened it somewhat but am lacking a flare nut wrench for a good job. Am I mistaken -- is the problem really the delivery valve holder? Seems like that would show up lower down, below the nut.

Your post is very helpful and well done!

 

[psneeld]

I am seeing fuel around the injector tube where it exits the top of one of the nuts on my Minimec pump. I assumed that it was just a loose nut -- tightened it somewhat but am lacking a flare nut wrench for a good job. Am I mistaken -- is the problem really the delivery valve holder? Seems like that would show up lower down, below the nut.

Your post is very helpful and well done!

I had one where tgere was a crack the tube right at the top of the nut.

Weeped for 100 hours or so then one day looked like arterial bleeding. Short stopped the day and replaced the pipe.

Eezy peezy as I had an extra pipe and was easy to see the crack.

 

[Scurvy_Dan]

Doug H and psneeld,

On our fuel leak, diesel was weaping out from where the Delivery Valve Holder threaded into the Injection Pump. Originally I thought it may have been the pipe or the fitting that had cracked or had come loose.

I would run the engine slightly above idle (increase the fuel pressure) and clean away any leaking fuel until you can verified the source of the leak.

Fair Winds,

Captain Dan

 

[R_p_ryan]

Well done! This is the kind of information that allows those with technical skill to participate in the type of boating that was reserved for those with money to burn.

 

[catalinajack]

$100 for a rebuild of an injector line?! My goodness, one may purchase brand new lines from American Diesel for $90. Brian could have them shipped to you probably in less time than to have one rebuilt. I know cuz I bought one last year to replace the spare I used to replace the cracked line that I experienced underway in the St. John's River. Sprayed fuel all of the engine. A nice mess to clean up. Fortunately, we had six spare lines aboard.

 

[Xsbank]

Just remember that if you are messing with hydraulic leaks with the engine running that the pressure is high enough to inject you with fuel too. Very hazardous, be careful.

 

[edwmama]

Hello Cal sailors

My original cal cruising 46 hull no 5 came with a Perkins 4.236 engine

For years I could only do max of 14 to 1600 RPM on cruising (6-7 knots)

After much trouble turns out the injectors where clogged or partially clogged

And the marine growth build up in the heatexchanger impeded cruising at higher RPM

cuz of over Heating


NOW that I've got all that resolved, the boat wants to fly

Now I can do 2200 to 2400 RPM in a heartbeat and cruise at 8.5 to 8.7 knots

And water gushes out in the back exhaust like Niagara Falls

What I have discovered now is,

After a 4 hrs trip to Catalina island, (from Marina del Rey ) a mere 28 nautical

Miles away, my engine oil is LOW and requires a top off 1 to 1.5 quarts of oil!

ITS BURNING OIL at much higher rpm

The engine runs smoothly, no overheating no black or blue smoke, good sound

I do see a slight white fog coming out of the exhaust but that may

Be from the coldness of the water and the fact the exhaust spends 1/3 of time

Underwater while cruising

But this oil loss is really annoying and worrisome

The engines runs so well though

The engine hours barely reads 1250 hrs

Had the injector pump and injectors rebuilt last year

The oil and antifreeze is clean, no cross contamination, no visible leak anywhere

Any advise?

I have not tried running at just 15-1600 to see if this persists

Would appreciate any thoughts




Edwin
Cal Cruising 46
MdR

 

[kremek]

Great info!!
No leaks now but with 2 and they are now 39yrs old will keep in a file for use if and when a leak develops.

 

[bgillroy]

Unsure of your plumbing but if you have oil cooler, oil side tube leak sends oil into the shell side water which oil then gets shipped out exhaust with the water.

 

[Paula T]

Very useful article! Especially with the part/order numbers and link. I have the Marlin Ford Lees Marine with same pump. Regarding the steel and copper washer, why are both included in the kit and why did you use the steel ones rather than the copper please? Thanks

 

[ronobrien]

Delivery valves

Nice post Dan. I thought some other background might be of interest. I was a mechanic for Mack Truck years ago, and Mack had 2 mechanical injection pump styles. The American Bosch & the Robert Bosch (German). The Americans you could service the delivery valves on the engine, but there were no crush washers, you had lap the valves in on a lap block to get them to seal. The Robert Bosch could not be done on the engine as removing the delivery valve altered the internal pump timing. These could only be done off the engine so that they could be re-calibrated on a calibration stand. That was unless you had the very special alignment jig that was installed on the valve before removal. The RB pumps were supposed to be better, but we all thought they were a pain in the butt. I just closed on a 1973 GB 36 with twin Lehman 120's, so I am always interested in information regarding them. Again, nice post, thanks for the info. PS anyone know about the pump oil change interval and oil type? Thanks

 

[catalinajack]

The early advice from American Diesel was to change the pump oil every 50 hours. Bob Smith later changed his advice to as many as 150 hours. I spilt the difference and change at 100 hours.

You should also consider retorquing the cylinder heads and then adjusting the valves. The valves on a FL120 should not be adjusted without first doing the heads. Brian Smith recommends adjusting the valves at no more than 1,000 hours.

Nice post Dan. I thought some other background might be of interest. I was a mechanic for Mack Truck years ago, and Mack had 2 mechanical injection pump styles. The American Bosch & the Robert Bosch (German). The Americans you could service the delivery valves on the engine, but there were no crush washers, you had lap the valves in on a lap block to get them to seal. The Robert Bosch could not be done on the engine as removing the delivery valve altered the internal pump timing. These could only be done off the engine so that they could be re-calibrated on a calibration stand. That was unless you had the very special alignment jig that was installed on the valve before removal. The RB pumps were supposed to be better, but we all thought they were a pain in the butt. I just closed on a 1973 GB 36 with twin Lehman 120's, so I am always interested in information regarding them. Again, nice post, thanks for the info. PS anyone know about the pump oil change interval and oil type? Thanks

 

[Comodave]

In the last seminar that Bob Smith gave before he passed, he said to start at 50 hours and see if the oil is diluted. If not then extend it a bit more and see if it is diluted. He said every engine is different and you need to find the sweet spot for your engine. One member in the seminar said he had 2 120s. One had to be changed at 50:hours and the other one could go 100 hours. So I would look at the oil at 50 and if it isn’t diluted then try 60 and so on. Good luck with your new boat. Have fun!

 

[catalinajack]

Dave, good point. I measure the volume of oil drained from the pumps. Even at 150 hours I have never seen oil in volumes in excess of the initial fill. So, doesn't that mean fuel dilution is really not very much? I once talked with a FL120 owner who did not become aware of the oil change requirement for FOURTEEN years. He did find that there was a lot of fuel dilution when he changed the oil but with no apparent damage to the pump because he had continued to use that pump for several more years and was continuing to do so. This was not a lightly used vessel. I have a sense that there has never been a real test of how long these pumps would last with infrequent oil changes. Still, I will continue to change my oil every 150 hours. Easy enough to do and not costly.

In the last seminar that Bob Smith gave before he passed, he said to start at 50 hours and see if the oil is diluted. If not then extend it a bit more and see if it is diluted. He said every engine is different and you need to find the sweet spot for your engine. One member in the seminar said he had 2 120s. One had to be changed at 50:hours and the other one could go 100 hours. So I would look at the oil at 50 and if it isn’t diluted then try 60 and so on. Good luck with your new boat. Have fun!