8BA really high oil pressure

37coop

Well-known member
Hello all , further to a previous thread from me ....rebuilt engine on my 51 F1 with new oil pump,o.k for 300 miles ,trip to USA for a month and on return when starting oil poured out of the oil filter can lid ,after much faffing about fitted an O ring and instead the oil squirted out of the pressure sender ,after advice from the barn I fitted a mechanical oil gauge (sunaco 100psi new )at tickover it sits at 40psi when pushing the throttle at standstill it shoots past the 100 and rests at the back of the needle stop,at 40mph it reads 80 and at 50 it reads 100,when switched off the needle sits at 10, I tried a different identical gauge and exactly the same result including sitting at 10 when swirtched off ,I guess its the pump at fault ,I cant use the old one as the bolt lug has broken ,apart from sending to the States for yet another pump any ideas? and would the truck be o.k to drive about as is ? still no leaks after a 50 mile drive . any advice would be appreciated as always , many thanks Jim.
 
Where did you get the new oil pump? What brand? Did you get a high volume pump or a std. pump?. I wouldn't drive it with that oil pressure, it's not good for the engine. Remove the pump and check the relief valve and spring, compare it with the valve and spring on your old pump. Walt
 
Where did you get the new oil pump? What brand? Did you get a high volume pump or a std. pump?. I wouldn't drive it with that oil pressure, it's not good for the engine. Remove the pump and check the relief valve and spring, compare it with the valve and spring on your old pump. Walt

Hello Walt ,I bought the pump with a rebuild kit ,pistons,rings bearings etc from Patricks when i was in the States and staying with an old V8 friend who uses him and reccomended him ,as it was part of the package i assume its a standard pump,cheers Jim .
 
Hello Walt ,I bought the pump with a rebuild kit ,pistons,rings bearings etc from Patricks when i was in the States and staying with an old V8 friend who uses him and reccomended him ,as it was part of the package i assume its a standard pump,cheers Jim .

I've used quite a few of Patrick's pumps, have had no problem with them. Pat has them made someplace, there just like the Mellings pump, they have a P on the cover instead of M. BUT, you still have a problem, You've got to remove that pump and check the relief valve and spring. Walt
 
The pump pressure spring and valve that control the rate of oil pumped maybe stuck open, or the valve that pushes against the pump body on the pump end of the spring could have some dirt or grit holding it open or stuck off centre.....
Check the pump you had used originaly to get an idea of what you're looking at.....
Or look at the Vanpelt Ford model ID site. It has a breakup of the pump showing the spring and valve.....
Oil pressure on my worked 8ba runs 35/40 psi 1000 rpm hot idle...65/70 psi normal driving...12yr's running...no problem........
 
The pump pressure spring and valve that control the rate of oil pumped maybe stuck open, or the valve that pushes against the pump body on the pump end of the spring could have some dirt or grit holding it open or stuck off centre.....
Check the pump you had used originaly to get an idea of what you're looking at.....
Or look at the Vanpelt Ford model ID site. It has a breakup of the pump showing the spring and valve.....
Oil pressure on my worked 8ba runs 35/40 psi 1000 rpm hot idle...65/70 psi normal driving...12yr's running...no problem........

The bypass spring in the valve valley is being pushed CLOSED by spring pressure and if there is a late oil pump with a bypass valve that is also being pushed CLOSED by a spring that is to strong or shims on the spring or springs. If there are two bypasses it's unlikely both would be to strong unless someone fooled with them, the weak one would still release the high pressure. I have tested a number of oil pumps out of the engine and all will put out 100 lbs which is controlled to the engine by the bypass spring. As stated numerous times I wouldn't put a new or used pump in with out testing it first. G.M.
 
The pump pressure spring and valve that control the rate of oil pumped maybe stuck open, or the valve that pushes against the pump body on the pump end of the spring could have some dirt or grit holding it open or stuck off centre.....
Check the pump you had used originaly to get an idea of what you're looking at.....
Or look at the Vanpelt Ford model ID site. It has a breakup of the pump showing the spring and valve.....
Oil pressure on my worked 8ba runs 35/40 psi 1000 rpm hot idle...65/70 psi normal driving...12yr's running...no problem........

Thanks guys ,I will take all advice and indeed if I get stuck I will give Jim a ring ,I know he is "proper"
I have just sent off to Oniell over here for a set of sump(oil pan) gaskets and now up to the garage , over the pit and the tedious job of removing the oil pan ,can really do without keep going backwards on this truck .
thanks again Jim .
 
I,m ready to change the oil but have been running 15/40.
would I be able to remove the pump with taking out the removable circular plate around the oil plug or is it the full oil pan needs to be removed ?
 
You have to drop the whole pan out, but that's relatively easy to do on the trucks. Jack it up by the frame (not axle) to give clearance to the axle and connecting link, pull the starter, and drop it out.
 
I,m ready to change the oil but have been running 15/40.
would I be able to remove the pump with taking out the removable circular plate around the oil plug or is it the full oil pan needs to be removed ?

All you require is 10w30 oil. Do that first and report back.

R
 
I just got the 280 running again and I have 10 lbs at idle and 40 at 2k with the engine up to temp. Running 5-20 oil, I tink this is perfect.
 
Thanks guys ,I will take all advice and indeed if I get stuck I will give Jim a ring ,I know he is "proper"
I have just sent off to Oniell over here for a set of sump(oil pan) gaskets and now up to the garage , over the pit and the tedious job of removing the oil pan ,can really do without keep going backwards on this truck .
thanks again Jim .

Why don't you pull the intake manifold and check the bypass in the front of the valley. You can spin the engine with the plugs out with 12 volts to the starter. The oil pressure on the mechanical gauge will be the same as driving at 50 MPH. Even if the pump has a bypass that's not opening the one up in front will relieve your excessive pressure if it's working. G.M.
 
37coop, as I follow the archives you were breaking-in your motor in Sep '14 then had the filter canister start leaking Dec '14. Upon fixing that, the filter hose at the block suddenly started leaking. I don't think this is coincidence. It really does seem your pump's relief valve is stuck closed and trying to send full volume and resulting pressure through the motor.

Lonnie
 
The bypass spring in the valve valley is being pushed CLOSED by spring pressure and if there is a late oil pump with a bypass valve that is also being pushed CLOSED by a spring that is to strong or shims on the spring or springs. If there are two bypasses it's unlikely both would be to strong unless someone fooled with them, the weak one would still release the high pressure. I have tested a number of oil pumps out of the engine and all will put out 100 lbs which is controlled to the engine by the bypass spring. As stated numerous times I wouldn't put a new or used pump in with out testing it first. G.M.

probably sounds silly but how do you test it out of the engine ? do you use an air line for pressure ,going up the garage right now to make a start on taking off the starter motor then the oil pan ,how about if I swop the new (faulty?) spring unit for the same off the old one , thanks .
 
There are several possible problems. It is even possible the pump body has not been properly drilled for the bypass to function. Only a careful examination can give you the answers. If all the casting and drilling is correct and if the correct spring is in place the relief valve spool might be difficult to remove. If 100+ lbs of oil pressure doesn't move it what can you do with your fingers???

Testing, external to the engine, is done with a specially designed and constructed fixture and a bucket of oil. The fixture includes a ball valve(or similar device) for controlling the pump output flow, and a pressure gauge. The flow is observed while the pump is being driven by a HD 1/2" drill motor. As the ball valve provides restricted flow the pressure and relief valve opening point are observed.
 
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JWL you got my attention; maybe a pic of this fixture (I don't care about the valving)
I know about that. So I'm thinking machining this fixture from Alum. Do I need
"0" rings or not? This is a perfect shop tool we can really use.. My mind has a picture
of this, but I would like to see what you have...

thanks Sam
 
I cut up an old block to make this test rig. Gotta love the sawzall.
 

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