Temperature Sending Unit

[ccriders]

I'm going to replace the water temperature guage and sending on my Atomic Four. What is the best product to presoak the sending unit for a clean removal and what is the best product to treat the threads when installing the new sending unit?
I find that PB Blaster is not particularly effective for stainless steel screws in aluminum, but have not used it on brass to iron fittings.
I appreciate any advice you might have.
Thanks

[tommays]

PB is pretty good

Raw SS and aluminum is one of natures better locktites and right there with red

I really have not had a real bad time with senders as they are brass and only have a few threads in the block

Just be sure to go at it with a 6 point tool as once you round it off you kind of screwed

[billyruffn]

Here's an easier, cheaper solution I used for several years after the temperature sensor packed up: buy an inexpensive, digital hot tub thermometer -- they come with the sensor at the end of a 5 ft (or so) insulated wire. Attach a small fishing weight to the sensor end of the wire and drop it down a cockpit drain. You don't need water temp all the time -- normally, only when you're thinking of going swimming or wanting to detect entry or exit from an ocean current (like the Gulf Stream). The hot tub thermometer works well for this purpose and when not needed it fits easily in a drawer/locker (the read out unit is really small 2 x 2x 1 inch.)

I have since replaced the speed paddle assembly and now have a proper temp sensor installed. The hot tub thermometer now serves as a battery temperature read out when I'm putting a big charge in the batteries on a hot day. I wedge the sensor between the cases of two batteries and set the display unit where I can see it easily.

[Faster]

Originally Posted by billyruffn

Here's an easier, cheaper solution I used for several years after the temperature sensor packed up: buy an inexpensive, digital hot tub thermometer --

... ummm.... BR, he's trying to change his A4's coolant temperature setup.. I think the sea temp might cause some confusion!

Neat idea, though...

[bwindrope]

You do not want to put anything on the threads of the sender as it needs electrical contact with the motor block to ground the unit. I've replaced and removed mine several times and it really shouldn't be too tough. I've always found a crescent wrench to work fine, and they are not the best for anything really stuck. You may be surprised with the ease of removal. And PB is great, but likely not that helpful in this situation.

[RobGallagher]

Kroil

[billyruffn]

Originally Posted by Faster

... ummm.... BR, he's trying to change his A4's coolant temperature setup.. I think the sea temp might cause some confusion!

Neat idea, though...

Ahhhhhh, now I see what he's up to....I was ignorant of exactly what an Atomic Four was. Must be an engine. In which case my little Radio Shack hot tub thermometer can be employed thusly:

Drill a small hole in the radiator cap and insert the sensor end of the probe. Then.....oh, yea....that won't work....forgot about the pressure involved. Well don't drill the hole, just attach the sensor to the fill cap with a big glob of silicone. Very seamanlike, eh?

[dorymate1]

The scary part is someone might actually try that silicone bloop idea. lots a luck with that one

[billyruffn]

Originally Posted by dorymate1

The scary part is someone might actually try that silicone bloop idea. lots a luck with that one

Hey! What you got against silicone? When the temperature gauge on your engine craps out I'm gonna bet you'd love to have a hot tub thermo and some silicone.

[dorymate1]

Not being a pool guy don't realy know what a hot tub thermometer is. But would most likely hose. Clamp. It wire tie itor safety wire it before silicone. Not heat resistant enough unless RTV that works when mechanically squeezed. Engine parts are also to greasy for silicone. Leave the silicone in the drawer for this one.