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MEP-803a, runs, but a couple quirks

mijoe

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Thanks, I've been running the house on it (post Irma) for about 4 hours now, and the temp has settled at just over 180 (indicated) and the oil pressure is about 23PSI and holding (verified with additional mechanical gauge). Seems like it will be fine for now...
 

CapePrep

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Was going to start a new thread on this, but this one seems relevant. Have had my 803 for a couple of months. The engine was supposedly a govt. rebuild with very few hours. Who knows the truth. On the gauge panel my oil pressure on cold start is 55PSI using Deere break in oil. As the engine gets to operating temp. the oil pressure slowly goes down to 20-25LB with a load on it. With an average load, this takes maybe 20 minutes or so. I was very concerned about what I considered low oil pressure. No lights, shut downs or anything like that. I wanted to verify gauge reading with a manual gauge. Hooked up a "T" yesterday to run the original sender and my analog. The analog gauge follows the electric gauge perfectly. So, I too have the same symptoms as other posters here. What are your thoughts on the reasons and cause of this? I considered putting in new bearings, but am wondering if this is just a design parameter. But, a 35PSI difference between cold and hot running seems extreme to me. Hope we can get a discussion going on this.
 

Light in the Dark

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David, have you done anything past a basic oil change, to flush the lubrication system? I know of numerous folks who have dumped their oil, and ran ATF for a short while, to do just that. Its a trick that I first saw Guyfang mention.... the ATF will scrub much nastiness out of the system. Might not hurt to see if your baseline numbers, could be more baseline. Worst case, you are out the cost of another round of oil, a filter, and a few bottles of ATF.

Do you run conventional, semi-syn, or full synthetic?
 

justacitizen

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Was going to start a new thread on this, but this one seems relevant. Have had my 803 for a couple of months. The engine was supposedly a govt. rebuild with very few hours. Who knows the truth. On the gauge panel my oil pressure on cold start is 55PSI using Deere break in oil. As the engine gets to operating temp. the oil pressure slowly goes down to 20-25LB with a load on it. With an average load, this takes maybe 20 minutes or so. I was very concerned about what I considered low oil pressure. No lights, shut downs or anything like that. I wanted to verify gauge reading with a manual gauge. Hooked up a "T" yesterday to run the original sender and my analog. The analog gauge follows the electric gauge perfectly. So, I too have the same symptoms as other posters here. What are your thoughts on the reasons and cause of this? I considered putting in new bearings, but am wondering if this is just a design parameter. But, a 35PSI difference between cold and hot running seems extreme to me. Hope we can get a discussion going on this.
if it were mine i would flush with ATF run until operating temp. then i would put straight weight 30 oil in it and run it,if the oil pressure will carry at 25 PSI and the safety doesn't trip during adding a load i wouldn't worry. you could always run straight 40 weight in it also. if heavy oil at cold temps concerns you just let the engine warm before you add a load.
 

CapePrep

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I still can't figure the da$% manuals out. Is this the "-12"???
ARMY TM 9-6115-642-24AIR FORCE TO 35C2-3-455-12
Not that I do this, but reading those things is like trying to find a specific quote in the bible!




David,

look up in the -12 manual what the normal oil pressure range is, and share it here with us, please.
 
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Light in the Dark

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David, lets break down the manuals to their major purposes

-10 is basically the operators manual. This should do this, for this reason, etc.
-12 is a lubrication order
-24 is the troubleshooting manual, and where the majority of your time should be spent absorbing.
-24P has all the exploded parts diagrams, and reference numbers (which can then be parlayed into sourcing of parts using the internet)

https://www.steelsoldiers.com/showthread.php?175591-MEP-803A-All-the-TM-s-you-need has all that are referenced above, plus some others (injector testing, trailer mount sets, etc).

When most jargon is thrown around, it is from -24 (IMO). There are also -24 and -24P for the engine only (also in that folder).
 
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CapePrep

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Rich, thank you for that break down! It really helps with the deciphering. Guy said to reference the -12, yet your post shows it came from the -10. My confusion continues.....
David, lets break down the manuals to their major purposes

-10 is basically the operators manual. This should do this, for this reason, etc.
-12 is a lubrication order
-24 is the troubleshooting manual, and where the majority of your time should be sent absorbing.
-24P has all the exploded parts diagrams, and reference numbers (which can then be parlayed into sourcing of parts using the internet)

https://www.steelsoldiers.com/showthread.php?175591-MEP-803A-All-the-TM-s-you-need has all that are referenced above, plus some others (injector testing, trailer mount sets, etc).

When most jargon is thrown around, it is from -24 (IMO). There are also -24 and -24P for the engine only (also in that folder).
 

Daybreak

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Howdy,

STOP! Do not do the ATF flush.

Some folks need to read and understand what your situation is first.

DRMO Reset unit, low hours. The oil pressure is fine. To understand what is happening, your engine has not been broke in yet. The John Deere Break in oil is also a lighter weight oil, and is non-detergent. You do not want to flush with ATF. You DO want the build up during break-in. The entire engine assembly needs to finishing mating surfaces. The break-in process is good loading 60-100% at all times. The break-in period is so critical to the life of a engine. Everything which happens during the break-in period could show later in life. That is also why some units have severe blow-by at 500 hours and are shot.

The oil pressure is fine. Run and good load on it, and also keep the oil filled. A break-in period uses oil sometimes. After around 100 hours, change your oil to a good diesel 15w-40 oil, and oil filter.
 

Guyfang

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Howdy,

STOP! Do not do the ATF flush.

Some folks need to read and understand what your situation is first.

DRMO Reset unit, low hours. The oil pressure is fine. To understand what is happening, your engine has not been broke in yet. The John Deere Break in oil is also a lighter weight oil, and is non-detergent. You do not want to flush with ATF. You DO want the build up during break-in. The entire engine assembly needs to finishing mating surfaces. The break-in process is good loading 60-100% at all times. The break-in period is so critical to the life of a engine. Everything which happens during the break-in period could show later in life. That is also why some units have severe blow-by at 500 hours and are shot.

The oil pressure is fine. Run and good load on it, and also keep the oil filled. A break-in period uses oil sometimes. After around 100 hours, change your oil to a good diesel 15w-40 oil, and oil filter.

First off, let me say I made a mistake by writing -12, when I ment, (and you all corrected me) the -10 manual. Oh well, once again my moth eaten brain fails me!!

The reason I wanted David to look, was to get him to use the books, and to see, that his oil pressure is not too low. We come back to that wise saying, "If it ain't broke, don't fix it". To know when something is wrong, you need to know what's right. Hence, RTFB. I don't know about anyone else, but when I read it, it tends to stick in my head, rather then someone telling me. So that's why I push people to read the books. In any case, "we good" now.
 

Daybreak

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First off, let me say I made a mistake by writing -12, when I ment, (and you all corrected me) the -10 manual. Oh well, once again my moth eaten brain fails me!!

The reason I wanted David to look, was to get him to use the books, and to see, that his oil pressure is not too low. We come back to that wise saying, "If it ain't broke, don't fix it". To know when something is wrong, you need to know what's right. Hence, RTFB. I don't know about anyone else, but when I read it, it tends to stick in my head, rather then someone telling me. So that's why I push people to read the books. In any case, "we good" now.
Howdy Guy,

You never made a mistake. It just shows the users need to do some reading.

hehe, you got dragged in by the ATF flush. Works great for old used and abused engines, which has its place. Just not with a reset unit.

Capeprep has a reset unit with low hours and Deere break-in oil.

All users should download and review all TM's for their unit. RTFM
 

DieselAddict

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That is the reason why I tend to ask the person the with question if they have looked at the manual. Its not to be coy or a jerk. Those manuals are VERY valuable and have a tremendous amount of great info. These machines are not disposable like what you get a your local big box store. To me they are more like a part of the family. Of course I may be a bit of a weirdo. ;)
 

justacitizen

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Howdy Guy,

You never made a mistake. It just shows the users need to do some reading.

hehe, you got dragged in by the ATF flush. Works great for old used and abused engines, which has its place. Just not with a reset unit.

Capeprep has a reset unit with low hours and Deere break-in oil.

All users should download and review all TM's for their unit. RTFM

do all reset units have new or rebuilt engines?
 

CapePrep

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All good stuff here guys! These are great conversations and I learn something new every day here. But, to the point of "low" oil pressure. I have built many engines and have never seen a 35PSI pressure drop from cold to hot. Agreed that the JD oil is like 10/30, but a "new" engine's clearances should be tight enough to handle that thin of an oil. But, I will follow the advice here, run it a while and change over to 15/40 at some point. I will say that when I did run it during our storm last month, oil pressure went to 25PSI and just stayed there the whole 24+hrs.
 

dav5

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All good stuff here guys! These are great conversations and I learn something new every day here. But, to the point of "low" oil pressure. I have built many engines and have never seen a 35PSI pressure drop from cold to hot. Agreed that the JD oil is like 10/30, but a "new" engine's clearances should be tight enough to handle that thin of an oil. But, I will follow the advice here, run it a while and change over to 15/40 at some point. I will say that when I did run it during our storm last month, oil pressure went to 25PSI and just stayed there the whole 24+hrs.
I won an 803a with 15 original hours and my pressure readings are identical to yours. I have JD break in oil in it as Daybreak suggested. I don't mind taking advice from Weird people. It has served me very well in the past.
 

Daybreak

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Howdy,

Here are some of my oil pressure readings during some load bank runs.

Acquired a Military surplus load bank for a MEP-802A and MEP-803A.

They all start high and drop down during hard loading. Hot oil thins out some. They go back up too when cooling.
 
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