BearKiller

Does anyone have some pictures of options for mounting the engine end of a mechanical water-temperature gauge??

I would like to keep the factory dash gauge functional.

Is it not a good thing to simply mount a TEE fitting in the sender location for both units??

Thanks.

jrussell

If your truck is a 5spd (without the tranny heat exchanger) then there should be a port available just underneath the thermostat housing. Mine was used for the tranny heat exchanger, so I used the port located directly on top of the thermostat housing. With a long mechanical probe in that top port you will definitely need to space it out some with an extra pipe thread piece. I just changed mine to an electrical gauge yesterday and the new probe was much smaller so I could screw it directly in just using the supplied reducer. If you go too far into that hole it will hit part of the thermostat (I think).

BearKiller

Try as I might, that plug on top of the thermostat housing is in there for good.

I considered sticking an impact wrench in it; but, I am a little afraid that I might bust something that I don't want busted.

Should I try the impact; or, should I try another hole??

The truck is 5-speed.

I will look behind the alternator and see if I can find that other hole.

Thanks.

jrussell

Time to whip out the ol BFH!

I used a 1/2 ratched with an extension and a breaker bar. It sure was tight, but once you crack it loose it comes out easy.

bgilbert

You must not of been tryin hard enough to bust that 1/2" plug open. Work at it again, impact, hammer whatever. That top plug next to the t-stat housing is the best place. You want to measure the water temp there because you will know exactly when the t-stat opens.

Not my truck, but this is exactly the way I did mine: http://www.turbodieselregister.com/u...d=5198&width=0

BearKiller

Thanks for that picture.

I got serious with that plug, and was just expecting the breaker-bar to break, when she give her milk.

I used a brass nipple and straight coupler to space the probe away from the thermostat, just like in the picture.

Poured the coolant back in, cranked her up, and no leaks.

The gauge finally got up to 140* (not much hotter than the thermometer on the porch).

Before installing it in the engine, I placed the probe in a pot of water.

As the water heated, the gauge went up.

When the water started a rolling boil, the gauge held at 212*.

Thanks.

JimmieD

I'm not familiar with this particular installation but in some cases it's necessary to 'bleed' the fitting/sender at install. Get it all together and leave sender loose and refill your water if any leaked out, then when water seeps out the sender's new location tighten it down. An air bubble can be nearly permanent under certain circumstances and can cause faulty readings on the gauge. This may not apply here, but if gauge is inaccurate give it a try?

jrussell

Jimmie is right. It sounds like your gauge is not working if it only got to 140* (unless that was just idling and not driving?). Due to the way the probe is installed an air bubble can easily get trapped in there causing goofy readings. I would do as Jimmie said and crack the probe loose and start it up to "bleed" the air out.

Another issue that could cause false readings is the probe being spaced too far out. This was the problem I had with my mechanical gauge. When I changed it to the electrical type the probe was half the size and didn't require any spacing. I posted this pic in the other water temp gauge thread, but I'll post it here again so people can see what I mean.

charliex25

I dont have a pic but above the t-stat there is a port for this use.

BearKiller

Engine was just sitting, idling, and it takes most of a day for it to get hot enough to open the thermostat, probably due to the massive Ford radiator.

The air-pocket makes sense, though, and I will bleed it, just to be sure.

Thanks.

BearKiller

Okay, I have loosened my sender, and bled off the air, three times.

After bleeding the air, the gauge functions as I think it should; then, in a day or so, it quits, and I have to bleed again.

My truck has two-inch body-lift, so the radiator tank is considerably higher than the engine, and full of coolant.

How are these air-pockets finding their way to my gauge-sender; and, what can I do to eliminate them??

I used a one-inch long nipple and a female coupler to get the sender up off the thermostat.

Should I try trimming the nipple and coupler to a shorter length??

Thanks.

JimmieD

I don't hav4 a 6BT here too study, but I would say you would do well to do whatever you can to get that sender as far into the waterway as possible without messing up anything else. There's a dizzying variety of plumbing fittings so maybe re-thinking the parts you're using might get you closer? Sorry, no better answer under the circumstances....

Micaiahfied

bear, i used the fitting that came with the mech gauge and put it in about the t-stat. i was changing the stat at the same time so i was able to look for clearence. i first time i wrenched it in was too low... so i took it out and put a little extra of the yellow (for gas) tephlon and got it nice and snug, it sat just high enough to clear the stat. also instead of going crazy in the hardware isle. if it is an autometer or autogauge gauge they make an extended fitting since they know thier mech probe is so long. i didn't use it for the water temp but it worked awesome with my tranny temp gauge. hope this helps. (oh also not leaks they way i did it... it is still plenty tight. over 2500miles on it this ways and the stat definately cycles correctly.)

Morsel

what size square socket goes in that plug? Looks like 3/8" not sure and I don't have that in my stash

BearKiller

Without me actually looking/trying, I am fairly certain no "socket" is required; as best I remember, the square end of a 1/2" breaker bar fits.
Someone please correct me if I am wrong.