Temperature gauge question

[coW52Dodge]

My temp gauge's capillary tube was cut by the PO so I bought a instrument cluster for a 48 off ebay. The parts manual has the same part number for a 48 and 52 gauge so figure I can just swap it out. I received it yesterday and it seems to work when I stick it in hot water.

I'll have to figure out how to test the oil pressure gauge as well, since mine isn't working.

Is the thread for the temp sender part NPT or regular? It is hard to tell..

In other words, does I need to wrap Teflon tape around the threads before I install it?

If looks like I can just take the old one out and put this one in.

Is there anything I should be aware of, other that to be careful with the capillary tubing?

[Merle Coggins]

The port in the head is NPT, or pipe thread. The nut behind the temp bulb doesn't seal anything. The bulb seats into the adapter, which is screwed into the head, and the retainer nut assures a nice tight seal between the bulb and the adapter.

So, to answer your question, no sealant is needed on the retaining nut but would be needed for the adapter into the head.

And if you have a pressure regulator on your air compressor you could use regulated shop air into your oil pressure guage to test it.

Merle

[Reg Evans]

When you take the old bulb out of the block maybe get an ice pick and scrape any loose crud out. I'm not sure on the threads but a little pipe dope or Teflon tape couldn't hurt.

The 48-50 gauge faces are painted black with white lettering and the temp needle hangs down from the top. The 51-53 gauges are paint gray with white lettering and the needle comes up from the bottom so....... they don't look the same. They will probably interchange though.

[coW52Dodge]

Thanks, guys.

Does that converter need to come out for me to put this new on in or do I just loosen the nut behind the old bulb and put the new one in?

Do I have to drain a bit of the coolant?

Since the plug is towards the firewall, I was wondering if I could just tip the truck forward by putting the rear on stands so not too much will spill out of the plug. Is that right?

[Merle Coggins]

It wouldn't hurt to drain down some coolant. Even though it's high on the engine, the radiator is still taller than that. Drain it out to a level below the head and you'll be fine. You can leave the adapter in the head and just loosen/remove the outer nut. The bulb will come out and you can slide the new one in and tighten it down. Refill the coolant, check for leaks...

Merle

[coW52Dodge]

  Merle Coggins said:

..And if you have a pressure regulator on your air compressor you could use regulated shop air into your oil pressure guage to test it.

Merle

Thanks - tested it and found that the oil pressure gauge also works like a chimp. I am a very happy camper. Not bad for a $10 ebay find.

I will need to fix the scales because they are almost gone. I could probably cad a new scale up and print it on sticker stock, unless someone here has a better idea.