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My mechanic buddy diagosed why the oil pressure light does not come on on my '52 Packard 200 with 288 engine, when the ignition is turned on. He said I need a new oil pressure sender, so I ordered one and it is in.

The service manual is silent on how to install it properly, and the torque specifications charts do not cover it either.

So, 3 questions:

1. What torque should it be torqued to? (I do have a torque wrench)

2. Are you supposed to use that white sealing tape on the thread? I ask because I assume this sender needs a ground connection (there appears to be only one wire to it), and wonder how it gets a good one if you use sealing tape.

3. If the engine is "off" (i.e. oil unpressurized),and cold, will you still get any oil leakage when you pull out the old switch?

Jim G

IIRC, it's a brass to brass thread fitting so there should be no need for the tape. You're right about the ground issue. Checked several different years for a torque spec & none found for unit, just the screw--I don't remember it taking too terribly much so just tighten snug being careful not to twist the brass off--you should be able to feel when its getting there. There will be no oil loss other than a possible drop or 2 unless some runs back from oil filter inlet pipe because it hadn't drained.

I think its just like any other tapered seat fitting, you just want to tighten it down till snug. If you wrench it down too tight, you will do more harm then good.

Thanks, guys!

Jim G

For anyone else making this replacement, pay close attentino to part numbers.

Max Merritt sent me a 439278, which is the sender for the 53-54 models, instead of the 416276 for the 51-52 models. JD there said it is interchangeable. Not quite so. The TERMINAL is different. The 438278 for the 53-54 models has a ring terminal, whereas the sender in my 52 right now has a spade temrinal. Changing the terminal is cheaper than the freight, so I'll change to a ring terminal, but it ticks me off having to do so, as I don't normally keep electrical terminations or the proper tools for them laying around. Fortunately, my pro mechanic freind does.

Jim G

That could have been a running part change. So in 1953 if you needed a new sender for your '52, Packard may have just given you the new style one. Happens all the time. Perhaps they found the spade style one was subject to coming loose, and changed to ring style. Or they just changed suppliers.

Not sure which terminal you refer to when you say spade but it sounds like something was replaced incorrectly before you got the car.

What we call spade in my industry is two prongs with a space of whatever stud size between so one doesn't have to remove the nut or screw as you would a ring but it fits exactly same.

If the spade you refer to is flat, and approx 1/4 in wide with a small slot that is pushed on a tab, then that is a more modern type we call a blade and never used by Packard to my knowledge.

They did use a push on that we call bullet type today which is round and approx 1/8 diameter but it would still fit on a stud (brake lite switch as example).

If you had a push on blade type before, then I think someone put an aftermarket sender on and maybe not the correct one for your car and might be why you're replacing it.

I recall that back in the day oil pressure sending units could be purchased with different settings that would give a low oil pressure indication. I believe the settings would range from around 5 lbs to around 10 lbs. Obviously, we always replaced a defective unit with one with the highest reading available. Just a thought.

Jim, I too live in Austin. I am in the Northwest part, off of Mesa.

JW: I am in Spicewood - 22 miles west of Bee Caves along Hwy 71 West, and 13 miles southeast of Marble Falls. Email me at JimGnitecki@msn.com or call at 830-693-6860. I'd love to meet and see your Packard. My Packard was owned at one point by Marvin James, who was the president of the Texas chapter of Packards International at the time. He is the one under whose ownership the engine was completely rebuilt and the interior redone. That was back in the 1980s. My Packard had only 4 owners before me, and was only unused once for a period of only maybe 7 years, when the original owner parked it before selling it to Marvin. I have substantial and impressive providence for it, including the original bill of sale. I even have the receipts for the first 20 or so years of registration.

HH565: even the wrong sender should have lighted up with the engine off, as zero psi will acitvate any sender, regardless of preset point. This particular sender that is in there is simply dead, as when my mechanic friend bypassed it, he did get the dash light did glow.

I think a sender with too high a psi activation point would drive you crazy, as it would come on anytime the engine is at idle!

Jim G

I installed the new sender this monring. My pro mechanic friend, Randy, told me that the white sealing tape IS a good idea, but that I should leave the first couple of threads of the sender that go into the car clear of the tape. He said this would keep the tape from getting into the bore of the oil passage, and would enable a satisfactory ground.

I tightened the sender only modestly (Randy warned me not to overtorque it and destroy the threads).

I installed a ring terminal on the wire from the chassis, and screwed it onto the sender terminal.

I turned on the ignition key, and the "low oil pressure" light did come ON! I started the engine, and the light did go out. Five minutes of idle, at first fast idle and then off the choke slow idle, brought no leaks from the sender (checked all around it with a dry paper towel), and absolutely NO oil pressure light flickering on even at slow idle. Looks like the sender now works properly AND my oil pressure is good even at idle.

Jim G