Installed Mechanical Oil Pressure Gauge on MEP-803A

[csheath]

Curiosity got the better of me on the oil pressure gauge accuracy.

I've been wanting to flush and change oil and decided to add a mechanical oil pressure gauge. I drained the unit, refilled with ATF, and ran it up to temp with no load. Drained again and refilled with Motorcraft 15W40 Diesel oil. I think it traps about a quart of oil the way the drain tube is positioned so I think I ended up with some ATF mixed in. Next time I will use a transfer pump and pump the oil out from the fill hole.

I purchased a 1/8" NPT brass street tee to add into the existing oil pressure line. Not sure of quality or accuracy but I selected a Made in USA, Marshall oil pressure gauge.





Cold I was reading right at 50 PSI on both gauges.





I ran it up to about 160 degrees with no load then added 20 amps for 30 minutes then another 20 amps for an hour. The gauge on the control panel was reading right at 20 PSI where it usually does when fully warmed and loaded. The mechanical gauge was at 18 PSI. The machine runs perfectly smooth and quiet and has never shut down with any faults. The unit has a 180 degree thermostat but never quite gets there. It stays just under 180 even after an 8 hour run and tests with a IR gun indicates it's pretty accurate.

 

[Light in the Dark]

Excellent post. Thank you.

When I get around to it, this sounds like a worthwhile mod to my 802. If for nothing else than to scratch my mechanical redundancy itch.

 

[kloppk]

I assume you saw your Freq gauge was at 55 Hz.

 

[csheath]

I assume you saw your Freq gauge was at 55 Hz.

Yes it doesn't work. I replaced my power and voltage gauges with digital meters. The new digital voltage meter has a frequency and hour meter Incorporated in it.

 

[justacitizen]

it will run for years with 18 psi. it would be interesting to see what the psi would be on the next oil change with a different brand of oil and without atf mixed in too.

 

[Light in the Dark]

Model number on the gauge used?

 

[csheath]

Model number on the gauge used?

Marshall Instruments

CW00100 / Press Gauge with 1/8" NPT Connection

Bought from StreetRays for $18.74

 

[csheath]

it will run for years with 18 psi. it would be interesting to see what the psi would be on the next oil change with a different brand of oil and without atf mixed in too.

I would have liked to see it a little higher. It was over filled with Shell Rotella 15W40 before and the machine gauge settled into the exact same level after a long run under load. I may pour some STP or something in to see if it makes any difference but I'm not overly concerned about it. I have had good results with Motorcraft products in my Ford vehicles. I even used a Motorcraft FL910S filter on it. I don't think a different brand oil in the same weight would make any difference. The only reason I used the Shell in it before was I had a jug someone gave me.

 

[DieselAddict]

I Don't recommend STP in anything.

 

[maniatopoulosg]

I Don't recommend STP in anything.

I know it’s probably better to do more frequent oil changes then buy more expensive synthetics and other oils but what is the best oil for 803a


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[DieselAddict]

I personally use the 10w-30 Rotella T (Now marketed as T4) in mine. I've gotten good service from it.

 

[Daybreak]

I know it’s probably better to do more frequent oil changes then buy more expensive synthetics and other oils but what is the best oil for 803a Sent from my iPhone using Tapatalk

Howdy,

A good commercial 15w-40 diesel oil. Most folks will change the oil based on time in unit than hours used. Unless you hit a no power streak for weeks. Since the MEP-803A does not use like 8 gallons... (MEP-803A capacity 5.9 qts) It's not hundreds of $$$$ to change oil.

 

[Demoh]

Whats interesting is I have the exact mechanical gauge for oil pressure set up on my 802a and 803a that I kept for myself.... great minds think alike?

As for the synthetic talk and stuff, my $.02 is if it was used for prime power then sure, but the oil degrades faster from time (condensation, etc..) than it does from hours on the oil when used in a standby application. Thats why I like to get my break-ins done quick because I really dont trust oil past 12 months, especially if its not a unit where I know the weather and where its been at.

 

[csheath]

Whats interesting is I have the exact mechanical gauge for oil pressure set up on my 802a and 803a that I kept for myself.... great minds think alike?

As for the synthetic talk and stuff, my $.02 is if it was used for prime power then sure, but the oil degrades faster from time (condensation, etc..) than it does from hours on the oil when used in a standby application. Thats why I like to get my break-ins done quick because I really dont trust oil past 12 months, especially if its not a unit where I know the weather and where its been at.

What does your 803 run for pressure when warm and loaded?

 

[Demoh]

What does your 803 run for pressure when warm and loaded?

This is all going off of memory so take it as that.
Out of the 10 or so 802s and 803s I have all of the low hour units hover around in the 40s, some maybe down to 35. Not all of these are with the mechanical gauge though. This is with fresh deere 10w30 break-in oil. All of the high hour units (like 2500+ hours) hover around 20psi. I havent seen it lower than 18ish. The oil has varied and I dont have many high hour units, but from my memory of the units, having 10w30 in produces lower PSI than a 15w40 when fully heated and loaded in SOME cases. not sure which cases have tolerances that are bad enough where oil weight matters or if the oil pressure regulator doodad is playing a role.

Basically if the engine is new, there is plenty of oil pressure and the oil pressure regulator doodad bleeds so the oil pressure is rather constant. If the engine is old and tired, I havent been able to confirm or deny if the regulator is opening up at all. I dont really want to load 3 different oils into multiple old engines, load them for an hour to take readings because thats a LOT of wasted oil.

 

[dav5]

My 500 hr 803A had constant oil pressure at 28, with 15w40 oil. My 15 hour unit also had constant pressure at 28 after warm up, with 10 w30 JD break in oil.

 

[justicelee26]

I have a lead on a mep generator with a broken fuel gauge. Is that easy to replace with something aftermarket? Also does it affect the aux fuel pump?

 

[Light in the Dark]

It could be a bad gauge, it could be a loose connection... it could be a bad sender. All easy stuff. Don't let the gas gauge worry you too much. The aux fuel pump is actuated by a separate float.

 

[maniatopoulosg]

I know it’s probably better to do more frequent oil changes then buy more expensive synthetics and other oils but what is the best oil for 803a


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I used the mobil1 diesel version but oil pressure dropped ivy almost 10 pounds what do you guys think ?

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[DieselAddict]

I personally wouldn't use a 5w oil in these machines. I use 10w for winter and 15w for summer.

Edit - In Florida you should be OK using a 15w year round.