Oil Pressure Sending Unit Question

[BILLF/TRF]

I replaced the original 80# oil pressure sending unit off my 59AB engine because it was leaking. I thought I was smart and found the Willys unit that has a 0 -50# scale and with the help of a brass fitting I screwed it into the engine, attached the wire only to find out on start up that the needle on my 1936 coupe dash panel guage (0-50#) went up and right past the top reading and out of sight! What do you guys suggest I do now? The cheap under dash mechanical guage shows a reading between 50 and 60#.

 

[41ford1]

Hmmm. It's interesting the Willys unit doesn't appear to work. I have a 59A-B in my pickup. When I bought the truck it had a switch in stead of a sensor. That lead to some very strange readings. 0 at idle and 50 going down the road. I replaced it with a Standard Motor Products # PS-60 sensor. The readings now match a mechanical guage I used for trouble shooting. As far as finding the PS -60 I took a gamble and asked the parts man for a sensor in a 1980 F100 with a 302. It's been in there for 2 years and still working fine.

 

[Bruce Lancaster]

I posted around 4 crossovers to this in Echlin and Standard on old Fordbarn a week or two ago...will try to diggemup again, as that info from the old barn will be inaccessible for a while.

 

[Dee]

Sounds like something is "grounded"? I have a similar Kaiser unit in my car and it works just fine. Either the sender is bad or perhaps the lead wire or capacitor is grounded?

 

[Mr 42]

The Ford Senders and gauge works by Bimetal strips that heats up in the sender "send" pulses to the Gauge that have its own bimetal strip that heats up bends and and move the needle.

Most other senders uses resistance, if you connect a resistance sender you will get the symptom you describe. So try to get a Ford sender, and you will be on track again.

 

[Bruce Lancaster]

Hit the catalogs again; these are ones that appear to be workable. No guarantee, your mileage may vary.

Standard: ps108 is direct replacement for 41A 80 pound sender. ps 60 (fat) and functional equiv ps 17 are said to work, later crossover. Remember the 12v Fords are actually 6 there...

NAPA/Echlin: op 6061 is the direct one, there are great bunches of later Frd ones that would likely work.

 

[BILLF/TRF]

I am not saying my Willys unit does not work, I wondering why my 1936 Coupe dash oil pressure guage only goes up to 50#? Did the later flathead engines (like my 59AB)run with higher oil pressure and therefore need the 80# sending unit? I don't know what the pressure range was in the '46-'48 dash oil pressure guages. Anyone know?

 

[Kube]

During WWII the pressure relief valve was modified to allow the engines higher oil pressure. At that time, the dash gauge was also changed to reflect a maximum of 80# (reading). prior to that gauges read a maximum of 50#.
Original sending units for your car had NO markings on the base. When Ford began to utilize the higher (80#) relief valves, the sending units began to be stamped either 50 or 80 on the base.
To get the proper reading the dash and engine gauges must match. that is, a 50# sender and a 50# dash gauge.
Hope this helps.
Mike

 

[GITCHIGUMI]

I think Dee may have your answer. I have a 41 Fordor. On start up the needle in the dash gauge would disappear to the right. I installed a mechanical gauge and noted that pressure would register 50lbs or so at startup and then settle in at 20 to 30 when warmed up. The gauge needle was still buried out of sight. A quick check to determine if the wire from the sender to the gauge is grounded is to turn on the ignition switch but don't start the engine. If the needle on the gauge moves, as mine did - way over to the right, the wire is grounded somewhere. I bypassed the harness wiring with a new wire and presto - I now have a gauge that reads like it should. Just did this yesterday.

Guitchi

 

[rickmass]

Mr Lancaster you said 12v fords are actually 6 volt,s.Ihave 12v gauge,s some one gave me ,so chould I use them on my 6 volt TRUCK.Rick

 

[TomO]

If you have the 80# oil pump and relief valve, you must use the 80# sending unit. Your mechanical gauge is showing 50-60# that is at the top of the scale fro the sending unit and the gauge.

Change to an 80# sending unit and your gauge will read near the middle of the range. With the 80# sending unit 40# is about half way. If you want to be more accurate,connect the sending unit up to your air compressor, connect wires to the gauge and ground and use the adjustable regulator to vary the pressure to the sending unit

 

[Walt Dupont--Me.]

I replaced the original 80# oil pressure sending unit off my 59AB engine because it was leaking. I thought I was smart and found the Willys unit that has a 0 -50# scale and with the help of a brass fitting I screwed it into the engine, attached the wire only to find out on start up that the needle on my 1936 coupe dash panel guage (0-50#) went up and right past the top reading and out of sight! What do you guys suggest I do now? The cheap under dash mechanical guage shows a reading between 50 and 60#.

So, you say the mechanical guage shows 50-60# cold and your electric guage show better than 50# cold. SO, what does it show after the engine warm up and the oil thins out? Walt

 

[35 5window]

The sending units are matched to the gauge so the 35-36 gauges need the 50# sending unit and the later cars where the pressure was higher need the 80# sending unit as well as the proper gauge to read it other wise the gauge wont read correctly in either case match the sending unit to the gauge regardless of how high the oil pressure Like the 35 and 36 rebuilt 21 stud engines use a higher relif setting in thre oil pump to achieve an 80 lb. pressure but when it gtets warm it comes down to around 20 or lower at Idle so use the 50# unit with the 36 gauge or 35 gauge If in doubt use a mechanical gauge like a Stewart Warner unit to calibrate or check out . The needle will go all the way to the top and beyond when cold and settle down to mid to lower reading while hot and running
These older gauges are just about as bad as idiot lights anyways. all they did was let you know
you were getting oil pressure to the mains and rods hopefully ! Use an undermount gauge that uses oil pressure to function if you want to be sure whats going on with your oil pressure. I dont know of any Ford gauges in those years that gave a pressure reading in pounds anyways just marks high medium and low

 

[Ian NZ]

I have tested the scale on a lot of 50 lb and 80 lb senders, and if you found one that read near enough you were lucky, most of them were a waste of time, I even received a new old stock one that was on Ebay, that one would not read at all, so I would not buy another one on Ebay unless it has been tested. I have found out even the normal piped pressure gauges read all over the place.

 

[Walt Dupont--Me.]

I replaced the original 80# oil pressure sending unit off my 59AB engine because it was leaking. I thought I was smart and found the Willys unit that has a 0 -50# scale and with the help of a brass fitting I screwed it into the engine, attached the wire only to find out on start up that the needle on my 1936 coupe dash panel guage (0-50#) went up and right past the top reading and out of sight! What do you guys suggest I do now? The cheap under dash mechanical guage shows a reading between 50 and 60#.

Chances are you 59AB engine has been rebuilt and uses the 8BA pump 80# pump. The 6 volt Willys 50# sender should work with your 50# guage. A good 59AB engine with an 8BA pump will have 55-60# cold. They will even run on the road at 2500rpm hot with 50-55#. they usually idel hot 15-20#. SO, when you engine wears out your gauge will probably be down where you can read it. Walt