I just inherited a 1956 Mercury Monterey from a family member, been in the family since my great-grandad bought it almost new in 1958.  

It starts & runs, brakes work, however, I'm getting zero on the oil pressure gauge so I dare not drive it.  It's definitely not low on oil.  I was told the motor is in pretty good shape but I also know it hasn't been driven much more than up and down from a trailer in the past 5-10 years.

As far as I can tell, looks like this is an electronic gauge?  I'm an old Mopar person and the Y-block is definitely new territory for me.  Definitely need to get my hands on a service manual but I thought I'd ask here first.

If it's definitely not low on oil, then the next thing to try is a known good pressure gauge.  Mechanical gauges are cheap and easy to setup for quick tests.

The gauge probably is the reason.  The motor would not last long if it really had 0 psi.


Lawrenceville, GA

Thanks.  I have a handheld mechanical gauge but I'm not even sure where the sending unit is.  I see what looks like the sending unit on the driver side of the block, has one wire going into it but the wire is spliced and also attached to what looks like a capacitor or resister of some sort, almost looks like a distributor condenser.

Left Side of Block near Oil Filter. My Bet is the existing Gauge is not working.

  

There is a  post on here from 6 yrs ago on this .  I think you have found your sending unit.  There was also just post on here about removing the oil pressure unit.  It is headlined 56 Mercury oil pressure sending unit.......To find the thread on here, Click on Explore, then Tags, and look down thru to find it.  If you cannot, just google it & will see it on Y-blocks Forever.   Good luck !! 

One of the first things to get before working on your Merc is to get a Shop Manual.  This tells all (well almost all)

The posts above tells where the sender is.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

It is really simple. Put a drain pan under the sender and then disconnect/unscrew it. Check the size of adapter to use a mechanical gauge. Match it up and connect the mechanical gauge. Start the engine and check the gauge. If it shows pressure it is surely the sender. Is the dash gauge the stock one? I've never seen a oil sender connected with anything more than a single wire so I wonder if someone has tried to adapt another voltage gauge to work. With a mechanical gauge there is little that can go wrong. Oh, and if you install one permantly use a copper line. If the plastic line melts or breaks you have a major oil leak under pressure. A real mess.

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Found a factory service manual buried in the trunk!  Mechanical gauge reads fine so definitely has pressure.  Service manual makes no mention of this condenser thing attached but it looks factory.

The sending unit installed looks like this one (link here) which matches the picture from the service manual but I think might be the sending unit for the idiot light rather than a gauge.  When I turn the ignition on, the oil pressure gauge pegs out at 80psi, as soon as I start the motor, it eases back down to zero, which would indicate the on/off function of the idiot light sending unit.

What are some good source for parts on these Y-blocks?  Mine I believe is 210hp version of the 312, year 1956 with red valve covers and air cleaner.

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That sender is for a Light. The correct One for a Gauge is a big "Bell" shaped One. I will see if I can find a Listing for U to look at. The correct Ford # for the Sender You need is B6A-9278-A. Its a specific fit for Mercury. The Fords use the small Idiot Light Sender. Another good source for Engine and Mercury Parts is Macs Antique Auto. Request a Catalog. Interesting reading about what's available.  There's One B6A-9278-A on Ebay.  Also go's by Part # SW-380.

  

There are several shops. Try searching for 1956 Ford parts on a good search engine. https://goo.gl/aYWqyT
Also check out the link page off the home page of this site. There are many people here that have a lot of knowledge and experience with the Y-Blocks not to mention speed parts. Check John Mummert's site for a great technical section for identifying engines and other parts.






Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire