Need help with oil pump

[Anonymous-0]

Hi there,
I bought my NAA with a redone engine. The oil pressure was always really high (80lbs +), so after I read about high oil pressure on the forum, I decided to take a look at the oil pump relief valve spring. So, I took it out and measured the tension to be about 15lbs at 1.5inches vs the 9.8 that the shop manual says it should be. I ordered a new spring from the New Holland dealer, but it turned out to be the same spring. I then found in a forum that the correct spring is a C0ME-6670-A. I went to the New Holland dealer and this part number subbed up to part number 86608463. When I got the spring, it was different than the old spring. It is shorter (2.3" vs the 2.84") and diameter is larger (.415" vs .372"). Because of the larger diameter, it won't even fit, but the tension appears correct. So, now I am stuck. Anyone have any suggestions? Maybe someone could sell me a good used one? I am in Ontario. Thanks for any help you can give. It is getting frustratin, this has been going on for a few months now.

 

[ZANE]

The high pressure is probably not because of the spring. It is more likely that the relief valve plunger has developed a defect from wear patterns that is causing it to stick closed. Put the plunger in a drill and with emeroy paper take the defect off the plunger. It may sacrifice a few pounds of pressure but will still do it's job and not make the pressure so high. I've run into this several times over the last 60 years of fixing Ford tractors.

Zane

 

[TheOldHokie]

(quoted from post at 09:16:30 03/18/14) Hi there,
I bought my NAA with a redone engine. The oil pressure was always really high (80lbs +), so after I read about high oil pressure on the forum, I decided to take a look at the oil pump relief valve spring. So, I took it out and measured the tension to be about 15lbs at 1.5inches vs the 9.8 that the shop manual says it should be. I ordered a new spring from the New Holland dealer, but it turned out to be the same spring. I then found in a forum that the correct spring is a C0ME-6670-A. I went to the New Holland dealer and this part number subbed up to part number 86608463. When I got the spring, it was different than the old spring. It is shorter (2.3" vs the 2.84") and diameter is larger (.415" vs .372"). Because of the larger diameter, it won't even fit, but the tension appears correct. So, now I am stuck. Anyone have any suggestions? Maybe someone could sell me a good used one? I am in Ontario. Thanks for any help you can give. It is getting frustratin, this has been going on for a few months now.

McMaster Carr sells a 20" long length of .375 x .041 stainless steel compression spring for $5. It has a rate constant of 10#/inch. Assuming the fitted length in the tractor is 1.5" cut a 2.5" long piece off and you should be good to go.

TOH