Oil Pressure on 300 w/Pict

Va Gasman

Member
I have this new to me 300. I notice that the oil pressure raises slowly but goes 2/3 to 3/4 the way over on gauge after about 30-45 seconds. I also notice that when engine is shut off, it takes 15 seconds for the oil pressure to go back down. Is this a line and gauge issue? Be cause the engine runs quiet and I don't belive it is being shorted oil.
I changed the oil upon delivery and it was real black. The new oil has stayed clean after several hours of running.
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That is how my 300 works, it seems to take a while for the pressure to get to the gauge and to bleed off. I attributed it to the quite skinny line that the oil has to pass through to get to the gauge. It seems smaller than on other tractors with which I am familiar.
Zach
 
Get the oil out of the tubing. That small tubing needs to have air in it instead of oil or it will cause the problems you are seeing.
 
This is normal. The line and passages are a little dirty and the bearings a little worn. You have good oil pressure, so no worry.
 
You need to turn down the charge rate on the generator. If it stays that high, it'll overheat and throw the lead out of the armature.
 
Fritz,
This 300 has been converted to 12 volt. It has a nice little Alternator tucked away out of sight. I noticed that after it starts; in 3 seconds it has gone to full charge. How can I check to see if it's getting to much?
Thanks, randy
 
I see the same thing on my 350, especially when it is cold. The other day I fired it up when it was 25 degrees to move some round bales and it took probably 10 seconds for the oil pressure to begin registering and then it climbed very slowly. The pressure finally stabilizes about the same place as yours on the gauge. Sounds like we don't have too much to worry about, though.
 
Probably nothing wrong with the charge rate. Most all altenators charge more than the generator gages that came on those tractors.
 
X5 on the oil pressure thing. Nothing wrong there. It's fine.

If the ammeter settles back down to a lower charge rate after a few minutes, there is nothing wrong there either.

Do you have to crank the tractor a lot to get it started? That may explain the high charge rate.
 
To get the oil pressure gauge to respond quicker you need to get the oil out of the line between the engine and the gauge.
 
Check across the battery terminals when running at 1/2 throttle or more. It should be 14.2 to 14.8 volts. If more it has a bad regulator or is not correctly getting sense voltage. If it is a "one Wire" alternator It is the Internal voltage regulator. (I like and recommend 3 wire setups as they are similar to the way the alt was designed to be used.)
Contrary to others opinions, If there is nothing but oil in the oil pressure line, it will read almost instantly. Oil does not compress, it takes only a few cubic millimeters of oil to change the bourdon tube in the meter. If it was full of air, the tube would need to be run 60 % full of oil to move the needle to the correct mark. That delay with cold oil is why the meter reads slowly. Jim
 
seen several amp gauge's do that when there only 20 amp and the alternator is producing 45 had one or two that would hang up but didn't cause any problems still better than any 6 volt system
 
In cold weather what you are experiencing is normal I think. I have a Farmall 400 that does the same thing and it has a completely rebuilt engine and new gauges. In warm weather the oil pressure gauge registers pressure almost instantaneously once the engine starts.
 

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