mechanical oil pressure guage adapter thread size

[Mark Mathews Creek]

Howdy
question, as I purchase a mechanical guage to check my inconsistent dash guage on my 83 FJ60, can anyone tell me what the high pressure threaded adapter would be? I know most come with 1/4 or 1/8 inch threads. Also, where exactly does it screw into? Does the sending unit come out and the guage go in there?

thanks.

 

[Cruisergreg]

The only place I can think of on the 2F is where the stock sender is. That hole has some kind of funky fine thread that's not NPT like most of the parts store mechanical senders. Not sure if you would get the right adapter in the mechanical kit or not. Someone else will possibly chime in.

 

[Mark Mathews Creek]

additionally, the current sending unit in my 83 has a center contact and a male prong on the outer edge. I have been told that the male prong is a ground. I have ordered the "older" unit without the ground. Does it matter which unit I use and if I use the grounded unit, do I need to ground it out or can I leave it alone?

thanks

 

[Cruisergreg]

If you don't use some sort of sealant on the threads (like Permatex or teflon tape) you don't need the second ground, although the sender might provide a better signal.

 

[swank60]

When you hook up the mechanical guage, you have to pull off the entire sending unit. It's a pretty large unit that is situated under and is threaded in below your oil filter. If you want to keep the OEM oil pressure guage working, you have to rig up some sort of T fitting, otherwise, just thread in the fitting for the new guage and go from there.

As for the fitting, the guage I bought (sunpro) had a metric fitting adapter that came with the unit. I bought it from AutoZone - they also had for sale a metric adapter kit that had several different sized fittings in it. When you go to purchase the guage, just talk to someone and get them to set you up with an adapter kit (just in case your guage doesn't come with the adapter already)

 

[Mr. Toad]

Mark Mathews Creek asked "can anyone tell me what the high pressure threaded adapter would be? I know most come with 1/4 or 1/8 inch threads.

OEM threading is 1/8" BSPT, whereas the mech gauge kits use 1/8" NPT. Very close, but not quite the same. Some people run a NPT tap in the hole to make threads for the mech gauge to screw into. Others just jam on the NPT into the BSPT hole; it kinda works, but I wouldn't do it. Adapters are available, and some kits even come with the adapters (See Swank60, above)

Also, where exactly does it screw into? Does the sending unit come out and the guage go in there?

The sender comes out completely, and the adapter for the mech gauge goes in its place. If you want to keep using the OEM sender (so your instrument cluster makes an oil pressure reading), you can install a T fitting (Branch Tee, I think) into the hole where the sender is currently installed. You'll then have two "outlets" for oil pressure senders.

 

[Mark Mathews Creek]

what a great forum and so very helpful. I thank all those with so much knowledge! After further inspection, the assembly under the oil filter seems to have another possible connection point and I'm hoping someone knows what it is. as you look down towards the sending unit and right under the filter there is a bolt pointed forward on the filter housing. If I remove that bolt, is it threaded and a place to put a mech. oil pressure guage?

 

[Cruisergreg]

as you look down towards the sending unit and right under the filter there is a bolt pointed forward on the filter housing. If I remove that bolt, is it threaded and a place to put a mech. oil pressure guage?

Hmmm...My last 2F is long gone so I can't run out and check. I don't recall such an obvious location for a sender but its possible (GM motors often have such a sender location). Feeling adventurous? Remove the bolt and see if oil runs out - if it does install your sender. If coolant runs out you've tapped into the oil cooler circuit.

 

[Mark Mathews Creek]

I purchased a new sending unit, I was told on a 83 2F engine that I only needed the one with the center contact and not one with a side ground. Is this correct? Anyway, my guage didn't move so I thought it might be the guage. I put the old one on with the wire to the guage on the ground and nothing on the center contact and it works again. Why is that? It reads 2/3 when started and then slowly goes down to between 1/3 and nothing and nothing but always runs well. Why would it register off the ground and should I try another sending unit. If it is not knocking, is it safe to assume that I have adequate oil pressure?

Mark

 

[Godwin]

If you attach the oil gauge wire to the ground tab on the oil sending unit you will fry your gauge. I learned this the hard way.

 

[Mark Mathews Creek]

then that is probably why I am having 2/3 oil pressure and its dropping throughout the day. I will have to check with a mechanical guage am buying tomoorow.

thanks

 

[Cruisergreg]

I was told on a 83 2F engine that I only needed the one with the center contact and not one with a side ground. Is this correct?

Beware what you are being "told". In an earlier life I worked auto parts retail and I can assure you that much of what comes out of parts geek's mouths is on the spot BS.

My 86 had the ground pole but nothing connected to it; only one wire into the rubber cover and that was to the center pole. I doubt it makes any difference unless you are not getting good ground signal through the threaded portion. FWIW, my 86 sender lives happily on working with my 350. No ground wire.

 

[richj11]

Beware what you are being "told". In an earlier life I worked auto parts retail and I can assure you that much of what comes out of parts geek's mouths is on the spot BS.

My 86 had the ground pole but nothing connected to it; only one wire into the rubber cover and that was to the center pole. I doubt it makes any difference unless you are not getting good ground signal through the threaded portion. FWIW, my 86 sender lives happily on working with my 350. No ground wire.

I purchased a new sending unit, I was told on a 83 2F engine that I only needed the one with the center contact and not one with a side ground. Is this correct? Anyway, my guage didn't move so I thought it might be the guage. I put the old one on with the wire to the guage on the ground and nothing on the center contact and it works again. Why is that? It reads 2/3 when started and then slowly goes down to between 1/3 and nothing and nothing but always runs well. Why would it register off the ground and should I try another sending unit. If it is not knocking, is it safe to assume that I have adequate oil pressure?

Mark

Hey guys,

I was searching for some info on the oil pressure sender on my 1991 FJ80 and ran across this thread.

My gauge wasn't working at all. I found a wire loose on the sender. After reading this thread, I hooked it up to the center terminal. Nada! But when I hook the white wire to the outer terminal, the "ground" quoted here, I get a reading.

It sounds like what Mark was stating above. Maybe it is a non-OEM sender?

Mark, did you get that mechanical guage installed and figure out anything more about this?

Rich J

 

[WckedMidas]

i just did this with the pressure guage. We took a thread file and alterd the thread on the screw in piece from the sunproguage kit i bought. love the guages now that i have them.

 

[Mark Mathews Creek]

mechanical guage

I never bothered fixing the sending unit or looking for a potential bad guage. After confirming good pressure with the mechanical, I started to sleep well and just drove it.

thanks

 

[cruiserbrett]

I was at kragen and they had a guage install kit, that consisted of a bunch of brass fittings, one of which is the needed fitting to put a 1/8" NPT gauge in the 1/8" BSPT hole.

BTW, with two working senders, my old FJ62 registered near zero oil pressure on the dash gauge, but had 60 psi on a mech gauge. Toyota gauges flat out SUCK.

 

[loeky]

i just came across this thread while shopping for a new mechanical gauge myself. using the info above, i found what i'm pretty sure is the proper metric adapter for the stock 2F to mechanical gauge. i like autometer, so here it is @ $12:

http://tinyurl.com/bydvy

now i'm off to order me a gauge!