TR2/3/3A temp gauge - panel removal TR3A

[NutmegCT]

I'm about to repaint the instrument panel (wrinkle black). Nice and warm outside.

I've got all the gauges, switches, lights, etc. out except the temp gauge.

How should that be removed? After removing the bracket, do I somehow unscrew something at the tube entrance on the gauge? Or remove the entire capillary tube at the engine and pull the entire thing through the panel? or ....?

I don't want to "remove" that tube and/or gauge incorrectly and find I've destroyed something.

thanks.
Tom

 

[Bugeye58]

Tom, the capillary tube must be removed at the engine and snaked through everything. Just be careful not to kink it.
Jeff

 

[AweMan]

Yep remove it from the engine, DON`t break the capalary line, if you do you are looking at well over $150.00 to get it replaced. Not to mention the turn around time. There is an article on the forum about how to replace the capalary line yourself If need be.

 

[TR3driver]

Be sure to disconnect the battery while you're at it.

 

[Andrew Mace]

Yep remove it from the engine, DON`t break the capalary line, if you do you are looking at well over $150.00 to get it replaced....

And consider the fact that this might be the first time the bulb end has ever been removed from the engine, so it probably won't come off without a fight.

Unless you're planning to powdercoat the dash panel, I'd consider removing all the other gauges and switches, loosen the temp gauge and pull it as far away from the panel as the tubing will allow, support the panel as best you can, mask everything in sight, and repaint it essentially "in situ." I don't know if that's really possible, but it might be worth a try?

If nothing else, use some sort of penetrating oil copiously and frequently well before you actually try to remove the sender....

 

[MGTF1250Dave]

Aloha Tom,

Andrew's suggestion might be the least likely to damage the temp gauge capillary tube. Particularly if removing the bulb holding nut is difficult or impossible.

Check the fitting that holds the bulb in the thermostat housing and see if it can be loosened. IMO a flare nut wrench would be the best tool to use when loosening the nut. If it seems to be frozen fast, removing the thermostat housing will let you see what the inside of the threaded hole looks like. You may have some scale build up and gently scrapping it away will expose the threads. Applying a good penetrating oil, like PB Blaster at both ends of the bulb retaining nut might eventually get it to come loose. If it has been in place for about fifty years, it may be fused in place.

 

[Geo Hahn]

I have painted it in situ as Andy suggests... but wrinkle finish can be a trial & error process so much easier to do off the car... also easier if you can lay the panel flat.

Of course if you have it off you can have it powder-coated with wrinkle finish.

My sender was stubborn but with several soakings with PBlaster and a heat gun applied to the tstat housing it came loose for the first time in a long time (at least 20 years I know of).

Here's a pic of the tube routing in case you need to know:

Oh, and when I reassemble that connection I use teflon tape, not for sealing it but just for ease of disassmbly (since I usually find it easier to change the tstat, etc with the housing removed.

 

[martx-5]

One other thing about the wrinkle finish paint. Most of them require heat to get a good wrinkle. Doing it in situ might be a possiblility with a heat gun, but it would be much easier to do in the oven. That's what I used. IIRC, you will also need to get the panel horizontal to get enough paint on there. The instructions on my can say two or three heavy coats at five minute intervals. Then some heat. Read the directions on your stuff, and see if it's practical to do it in the car...I don't think so.

 

[NutmegCT]

Gentlemen - there is NO WAY I would have attempted this without your help.

Fortunately my temp tube was relatively easy to remove from the radiator head, altho' the nut looks like it was bludgeoned at sometime in its past. However ... look at the first picture (tube routing - very "creative"), and the second picture (doubled over U-shape bend under the heater coil).

I couldn't risk cracking that tube trying to straighten it at that under-heater bend, so I pulled the temp gauge about five inches out, covered it up, then masked off the dash.

Third picture is about ten minutes ago - the result of following the Plasti-kote Wrinkle Paint instructions. Sand surface smooth, wash with solvent, wipe off, paint "heavy", wait 10 minutes, repeat the "paint/wait" two more times. After each coat I held a hair dryer about five inches from the panel surface and slowly moved it around the panel.

Not great, but way better than before I tackled it (last picture). I'll wait 'til tomorrow to make a final evaluation. Also used this time to clean every gauge dial and glass cover. Man, what crud can build up during a measly 50 years.

Tom

 

[TR3driver]

IMO a flare nut wrench would be the best tool to use when loosening the nut.

/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif

If it seems to be frozen fast, removing the thermostat housing will let you see what the inside of the threaded hole looks like.

Unfortunately, I don't think so. The threaded part of the hole is larger than the opening into the interior, because the bulb seats into a taper below the threads. On the ones I've had, at least, the straight part of the bulb is a fairly snug fit into the smaller part of the opening.

If you do manage to get it out, smear some PTFE pipe paste on the bulb, both where it seats into the housing and where the nut seats against it. Then more paste (or antiseize) on the nut threads.

I've seen replacement housings as cheap as $10-15 on eBay (especially the TR4 housings which are slightly different but will fit fine), so if all else fails, it may actually be more economical to cut the housing away from the bulb.

BTW, I had Fred Thomas powder coat my panel some years ago, and it still looks beautiful.

 

[Andrew Mace]

... look at the first picture (tube routing - very "creative"), and the second picture (doubled over U-shape bend under the heater coil).

Wow...creative is not the word. I'm amazed that it has survived intact with such an exposed route!

Not great, but way better than before I tackled it (last picture). I'll wait 'til tomorrow to make a final evaluation....

Fingers crossed here, Tom, that it comes out well.

BTW, what's up with the fuel gauge? Doesn't look very healthy. Do you have a better one?

 

[NutmegCT]

Andrew - that fuel gauge is in the *before* picture. I did a bit of r&r on it a few weeks ago (below); fab'd a needle, cleaned and calibrated, etc. Now all the gauges are spiffy (and glass covered ...).

Would you advise I try to bend that temp tube back into the correct configuration (per GeoHahn's diagram)? It's creating the small "spirals" near the firewall that worries me.

Tom

 

[Geo Hahn]

Are you the guy who made a new fuel gauge needle using an old hand off a clock? If so then I'm prepared to think you can do almost anything.

My temp gauge was in the wrong spot in that center panel... put up with it for years but finally decided to move it. I straightened out the whole capillary tube -- that sucker is loooong, about 6' I think -- then routed it per the diagram. Nervous work at first but I finally got confidence the thing wasn't about to break.

For that series of loops at the firewall I wrapped it around a juice can to get tight loops without kinking.

 

[Andrew Mace]

Andrew - that fuel gauge is in the *before* picture. I did a bit of r&r on it a few weeks ago (below); fab'd a needle, cleaned and calibrated, etc. Now all the gauges are spiffy (and glass covered ...).

Whew; I feel MUCH better now! Seriously, it looks great!

Would you advise I try to bend that temp tube back into the correct configuration (per GeoHahn's diagram)? It's creating the small "spirals" near the firewall that worries me.

I'm not sure how brittle it might be after all these years. Assuming it's not really that brittle, I'd be tempted to shape it much as I tend to shape new brake lines...by bending it around whatever's handy and about the right diameter as a "mandrel" rather than bending it freehand!

 

[TR3driver]

Generally I agree with Andy; however in this case I would leave well enough alone. The spirals in particular do nothing (IMO) for the longevity of the capillary tube; and every time it bends, it comes that much closer to breaking and ruining the gauge.

Try to anchor it so that there aren't large unsupported sections to vibrate and break; otherwise I wouldn't worry about getting the routing "just right" unless you want to please a concours judge.

 

[mrv8q]

so if all else fails, it may actually be more economical to cut the housing away from the bulb.

This is what I had to do w/ mine.... consider yourself <u>very</u> lucky you could get it out w/o a pitched battle!

Just so you know, the capillary line is attached along the fuel line, alongside the head; TRF sells those.... If you need a pic, let me know.

You were brave to paint the panel in situ; I hope it turns out well for you. It wasn't until I painted my panel for the 3rd time that I figured out the old hair-dryer trick, and I'm happy w/ my results. Now's a good time to replace the O rings behind the gauges, if you don't already have them....

Don't forget, too, a new rubber grommet at the firewall for the temp gauge....

 

[NutmegCT]

quote: "I'm not sure how brittle it might be after all these years. Assuming it's not really that brittle, I'd be tempted to shape it much as I tend to shape new brake lines."

That tight bend ("kink") under the dash is what discouraged me from pulling the whole thing through the firewall; I'd have to un-kink from a tight 180 degree turn, and was/am afraid I'd break it.

That's the kicker. How brittle can those tubes get? Anyone know what they're made of ... and how "bendable" they are after 50 years? I can imagine trying the "around a juice can" technique (good idea, by the way), but feeling it suddenly go limp in my hand as I work with a previously straight (or tightly bent) length. They're not exactly available at every drugstore. Argh.

Tom

 

[TR3driver]

The material appears to be mild steel, which work hardens according to how much it has been flexed. Mine have almost always broken either right at the gauge, or right at the sender, where they tend to flex the most.

Even the ones that didn't break were wildly inaccurate; the one I took out still reads about 1/4 scale sitting on my shelf. I finally gave up and installed a 270 degree sweep gauge from Sunpro. About $25 at Pep Boys, and fit perfectly. Ran a wire for the light; now it's the only gauge I can read at night /bcforum/images/%%GRAEMLIN_URL%%/smile.gif