Block coolant drain threads

Does anyone know the thread size and pitch of the drivers side coolant to oil cooler threads. I am replacing the failed oil to water cooler with a air to oil cooler. There is no need for the lower hose anymore as I intend to reroute the throttle body coolant lines directly back to the thermostat area where it joins flow with this oil water cooler line. They really tucked that fitting away up in there. I suspect its metric pipe thread but just wondered if anyone really knows the tread pitch.

 

What type of failure did you have prior to your new idea?

Per your question: Maybe take the opposite end to nuts/bolts store to figure it out in person.

 

I had trace amounts of oil getting into coolant. But no coolant seeping back into oil. Proof after bypassing the oil cooler the trace oils never came back. Tested transmission cooler same way. Some folks were suggesting cylinder head gaskets. Way more work and was not the problem in this case. Another person on internet posted the piece but the wrong part number.

 

Part number should be 90404-53070 for the threaded straight connection union into the block from the oil cooler hose. Picture right part number wrong. The part number beside the part image is for a "Y" type hose union.

 

That nipple looks like the union I ordered and used at my rear diff for the breather extension. The part number seems like it from memory. It does have a British Pipe Thread.

 

That is what I was trying to determine before I remove it. Not many metric pipe plugs around here. Worst case I take it out and tap a 1/4" NPT inside it. Still if it's easy to get the right thread on a plug first I would go that way. Photo shows it as coming with thread sealant pre applied but the threads look straight not tapered. Still a mystery yet to be solved. It's in such an easy place to access...lol most likely have to remove the AC compressor just to get at it.

 

I’m 99% sure this is the union I used to screw into the rear diff. I remember talk of it being British Pipe Thread. Not sure of size though.

 

Mine didn’t have the thread sealant on it. It was about $11 and was a Toyota part.

 

I used this pn for the rear diff PHM,

 

Okay, but the differential one is smaller overall. This one is connected to 5/8" heater hose. The molded hose part from Toyota is $38 and three weeks away... The part number in the photo is most likely right according to local Toyota dealer. It still unfortunately, is in California. I suspected metric "straight threads" by the photo. It does not look tapered. Hence the pre sealant pipe goo. I really appreciate the info shared. Once I get it all re assembled I will post some good photos of the parts. The parts I specified should be a serious upgrade. Derale thermostatic fluid control valve 1/2" NPT ported to mate with the Derale 1/2" NPT ported block sandwich adapter. Some 5/8" single steel braided fuel line kits with AN 10 connectors. Never again shall my oil and coolant swap places...lol

 

This is what we got.

 

It is in fact 3/8" BSPT 19 TPI.
Photo of 18 TPI and 20TPI and 1.5MP.
None match so by default and measurements.
What we have in this Canadian 2004 4.7 litre V8 Tundra in Canada is a Japanese engine with British threads. Now to try to find a plug. Lots of fun.

 

It's back together. The only filter bas adapter I found with true 1/2" ports was Hayden 15735 coupled to a Derale 1/2" port thermostatic valve then plumbing lines are with Russell branded AN 90 deg fittings, Evil Energy straights and 45 degree and one Aeroquip 90 degree fiiting. I did a complete review of the differences in those three brands of reusable hose ends on Amazon. Evil Energy are a value leader good quality fitting. The aeroquip is very difficult to install as it pushes onto the hose. The others use a left hand thread to aid putting the hose nut on the hose. The oil to air cooler is an Evil Energy 10 row. Caution on drilling mounting bolts for new cooler. The radiator is very close. The fi al model was to remove all the un necessary hoses and piping from the Toyota oil water cooler. It required a 1/4" NPT fitting on the return line from the throttle body coolant passages to the thermostat housing. It works very well. Pay close attention to the Hayden and Derale flow direction the temp control valve especially as the new model has been altered. I had to remount it after I discovered that. In the pic uploaded it is incorrect. The hot oil must enter at the bulb cavity to regulate properly. This is not a typical home brew installation as there are some very difficult to access component areas.