M929 oil pressure

[Noah]

Hi all,

I am new here and newer to the world of military metal. I just bought my first last week, a M929a1 from Indiana. Yes... I am hooked, and am very happy with the truck.

So my question: I have been reading the operators manual an I see it says the oil pressure should be 15 psi when at idle, and 55-75 when operating. My trucks gauge jumps to 90 psi as soon as it is started and stays there during operation. I am hoping for some advice on this... sensor or pump?

 

[doghead]

That would be the minimum acceptable , at idle.

Your fine.

 

[Noah]

Well that makes me feel better. I was afraid 90 was to high.

I believe it just had service done in May... would you say go ahead and change all the fluids just to be sure? Or is there a good chance transmission fluid and gear oil is going to be fine?

 

[spartan_185]

Your sending unit and gauge may be on the fritz. I had a very nice M925 that did the same thing and would even drop to 0 psi at idle. It was the sending unit. I just replaced the gauge and sending unit with a manual automotive gauge with the tubing that runs down to where the old sending unit screws in. It has worked perfectly ever since, and the gauge even fit in the old hole in the instrument panel.

 

[Stoner63]

Funny about this post. I have been looking at M900 series trucks on GL. They sometimes have good photos of the gauges and the other day I saw a shot of a M923A2 at idle at 650 RPM and the Oil Pressure guage was at zero. That would scare the heck out of me.

 

[spartan_185]

Funny about this post. I have been looking at M900 series trucks on GL. They sometimes have good photos of the gauges and the other day I saw a shot of a M923A2 at idle at 650 RPM and the Oil Pressure guage was at zero. That would scare the heck out of me.

I would think that they wouldn't idle or run long with no oil pressure.

 

[Stoner63]

That's what I think. The guage was bad I would think or the guy who took the photo did not pay any attention to it. That scares me more.

 

[Suprman]

My a2's show very little pressure at idle then go up to around 45psi or so when driving. This appears normal and several other a2 owners have discussed it. I believe 10psi per 1k rpms is just fine.