Oil & Fuel Ford NAA oil pressure

[flyingcolors]

Rebuild 134 engine including new oil pump. initial start-up sounds great, but no pressure on the gauge. I removed the dist, and fashioned a long screwdriver to turn the oil pump with a drill, giving good volume flow out the filter port. New gauge and still no pressure. Is there a pressure regulating valve like on an 8N that might be stuck, or where could the oil be going? I'm sure the tube to carry oil to the rocker arm assembly is properly seated. Any suggestions appreciated. Thanks, Kelsey

 

[Jerry/MT]

Rebuild 134 engine including new oil pump. initial start-up sounds great, but no pressure on the gauge. I removed the dist, and fashioned a long screwdriver to turn the oil pump with a drill, giving good volume flow out the filter port. New gauge and still no pressure. Is there a pressure regulating valve like on an 8N that might be stuck, or where could the oil be going? I'm sure the tube to carry oil to the rocker arm assembly is properly seated. Any suggestions appreciated. Thanks, Kelsey

Did you check the main bearing clearances when you assembled the engine?
The oil circuit must have a relief valve but I'm not familiar with the engine systems to know where it's at. Usually it's built into the pump. Do you have a Shop Manual? Assuming you assembled the bearings with the correct clearances, the oil relief valve is a likely suspect. Could be stuck open or assembled without the control spring, etc.
By the way, congratualations on putting in a new oil pump. Most folks skimp on that part of the rebuild.

 

[flyingcolors]

Yes, all bearings were checked with plasti-gauge,and I followed the shop manual carefully. I also had ordered the DVD and found it useful for sequencing. It is so frustrating to have to undo steps to accomplish something that should have been earlier in sequence! I still have the old pump, and will examine it to locate the relief valve. Are there any internal oil journal plugs that may not have been replaced after the block boiling/cleaning process?
Thanks for your prompt reply, Kelsey

 

[jinman]

Rebuild 134 engine including new oil pump. initial start-up sounds great, but no pressure on the gauge. I removed the dist, and fashioned a long screwdriver to turn the oil pump with a drill, giving good volume flow out the filter port. New gauge and still no pressure. Is there a pressure regulating valve like on an 8N that might be stuck, or where could the oil be going? I'm sure the tube to carry oil to the rocker arm assembly is properly seated. Any suggestions appreciated. Thanks, Kelsey

There is a plug on the housing of the oil pump right above the gearcase. removing the plug gives access to the spring and plunger that regulates pressure. Since you said the pump was new, that spring and plunger could be missing or the wrong value. I think the spring compression is supposed to be something like 9.7 to 9.8 lb (EDIT: when compressed to 1.56"). I'd take the parts out of the old pump if you still have it. Of course, you'll have to drop the oil pan to get to the pump for this check.

 

[Jerry/MT]

Yes, all bearings were checked with plasti-gauge,and I followed the shop manual carefully. I also had ordered the DVD and found it useful for sequencing. It is so frustrating to have to undo steps to accomplish something that should have been earlier in sequence! I still have the old pump, and will examine it to locate the relief valve. Are there any internal oil journal plugs that may not have been replaced after the block boiling/cleaning process?
Thanks for your prompt reply, Kelsey

I suppose that some oil gallery plugs could have been left out in the cleaning process but I don't know much about your engine so If you have then on the engine, I certainly don't know where they are at. Youmight try looking on the New Holland web site at the parts drawings for the NAA. It may help you find something.

 

[tmajor]

Here is what I discovered about my NAA pump.

 

[Soundguy]

g-rotor pump or?

soundguy

 

[flyingcolors]

Yes, it is the rotor type pump. The relief valve is press sealed instead of accessed by a bolt.
There is enough pressure that the oil fills the tube to the gauge, about 10" above the rocker arm assembly, so there is volume being pumped, but minimal pressure.
When I get back home next week, I will try the simpler things first by removing the valve cover and pump with a drill through the distributor shaft port to see if there is a large leak up there. If not, Then remove the pan and pump from a bucket to see where the oil is going.
I appreciate all the help, Kelsey

 

[Soundguy]

i am at work and away from a manual.. but would think about a galley plug.. though with making volume.. oil must be going somewhere.. when you find it you will likely know what the issue is.

keep us posted!

soundguy

 

[flyingcolors]

Back after cataract surgery. It was really hard doing nothing for several days.

Yesterday I pulled the valve cover and drove the oil pump with a drill. No oil at the top end. Then pulled the pan and found lots of oil everywhere. Pulled the new pump and everything is snug and proper.
Then I removed the pressure gauge and blew air through the tube. Very free flowing air sound from the governor area. Removed the governor and front gear cover to find two 5/16 tapped holes behind the cam gear. I threaded a bolt into each and repeated the air pressure test to find no air noise up front and now getting air flow through the rocker arm overflow tube.
Can I just plug the tapped holes with a dome head screw with Locktite? There seems to be plenty of clearance between the block and the back of the cam gear.
Appreciate your help, Kelsey