M920 Oil Pressure sending unit PN source

[jamboly]

The oil pressure on my 920 gauge has been reading about 20-22 lbs, which would be to low. Today I hooked up a non electrical gauge and it read 35-40lbs, which should be about right. So in true shot gunning troubleshooting form, I have decided to replace the pressure sending unit, since I already have it out. However, the old unit was over sprayed when the engine was painted, and in the process of trying to remove the paint, I also removed the label and all it's markings. TM of search of 920 and engine parts manuals has not helped. Anyone know what the sending unit part number is and where I can get one.

 

[Castle Bravo]

The -24P TM says its a Stewart Warner 353-BY sending unit.

 

[jamboly]

Thanks for the reply. However, this is where the TM is not much help comment comes in. The 353 BY is actually a switch that activates at 15psi. I suspect it is the low oil pressure switch, even though the -24P TM lists item no. 6 (pn 2901-21) as a low engine oil pressure switch, which closes at 16psi and opens at 3psi. I thought it might be item no 1, which it lists as a 334AD, transmitter pressure, but in reality, the 334AD is a temperature sending unit. All that being said I have decided to do a little more troubleshooting before just replacing the sender or the gauge. I measured the voltage at the back of the gauge with the engine running. I get 6.3 volts across the terminals and the gauge reads 21psi. I was hoping that someone else that has one of these beast would take a voltage reading on their gauge and let me know the voltage and psi reading they get. This should at least tell me whether the gauge is working right.

 

[doghead]

http://www.eriksmilitarysurplus.com/gaseun.html

 

[jamboly]

I looked at gauges you provided the link for. They are the standard (MSXXXX) military gauges and sending units. The M920 does not have the standard military gauges and sending units. It appears to be Stewart Warner type commercial gauges.

 

[doghead]

http://www.parttarget.com/5930-01-107-6474_5930011076474_5965573.html

 

[jamboly]

doghead; the parttarget link is for the 353-BY, which is not the sending unit for the oil pressure gauge.

 

[doghead]

I linked it to show the other part numbers listed.

Sorry, I didn't realize it was the wrong part. (yes, I did read the previous posts)

 

[jamboly]

I hooked up a non electric gauge and it reads about 40psi. In order to determine if it is the sending unit or the gauge I could use some help. I was wondering if someone that has this class of truck would take a voltage measurement on the back of the gauge and tell me the voltage and the corresponding pressure reading. I can compare that to what I am getting to hopefully point me in the right direction.

 

[NDT]

Sender p/n's are 0-80 PSI is a Stewart Warner 279A. 0-100 PSI is 279B-F. I believe the sender is what is drifting off calibration. My 915 reads low too.

 

[glassk]

markings on flats


stewart warner 411 J
5930-01-107-6474

http://www.parttarget.com/5930-01-107-6474_5930011076474_5965573.html

353-BY also under Mfg numbers

 

[jamboly]

I got another M920 that had a leaking oil pressure gauge sending unit. In looking for a replacement, I ran across this post that I started several years ago. In looking back through the various replies to my post, I found that it had some good info as well as some very wrong info (some of which I posted myself). Rather than critiquing the posts, if you need a sending unit, get a Stewart Warner 279A. For the gauge, get a Stewart Warner 460R. Both are still available by doing an internet search. PS: you need a short 1/2in wrench to get the sending unit off and on the engine.

 

[Artisan]

I got another M920 that had a leaking oil pressure gauge sending unit. In looking for a replacement, I ran across this post that I started several years ago. In looking back through the various replies to my post, I found that it had some good info as well as some very wrong info (some of which I posted myself). Rather than critiquing the posts, if you need a sending unit, get a Stewart Warner 279A. For the gauge, get a Stewart Warner 460R. Both are still available by doing an internet search. PS: you need a short 1/2in wrench to get the sending unit off and on the engine.

jomboly So did you determine the 279A is a direct replacement for the 411-J ?