temp gauge instalation

[ampster63]

I am trying to install a new temp gauge on my 1972 MF 135 but when I screw the new temp gauge into the block it leaks. It appears to be the same as the old threads. Any suggestions?????

 

[Georgia MF]

(quoted from post at 21:41:33 06/06/11) I am trying to install a new temp gauge on my 1972 MF 135 but when I screw the new temp gauge into the block it leaks. It appears to be the same as the old threads. Any suggestions?????

Did you use any thread lubricant or sealer? Teflon tape generally works fine, but Rectorseal #5 is what I use when the threads are suspect. Be sure to let it set up for a bit before pressurizing. Most of all, don't over tighten or you can strip the threads. (Of course, this is assuming it's leaking through the threads.)

 

[ampster63]

IT APPEARS TO BE LEAKING FROM THE INTERIOR, WHERE THE TEMP BULB RUNS THROUGH THE THREADED PLUG

 

[Georgia MF]

I don't remember exactly how the bushing fits and seals around the bulb. But, if it's leaking between the two, and you can't pull the bulb off the bushing to look for burrs or gouges, you might want to exchange it for another one.

 

[samn40]

I find slipping a rubber 'O' ring over the bulb so the nut tightens
against it helps in many cases.
Sam

 

[supergrumpy]

had same problem, the hollow threaded piece bottomed out before the bulb was cinched down inside the bore

I made a spacer by cutting off the front piece of the old hollow tube, slit it so it would go over the capilary tube

 

[ampster63]

thanks for all the tips. Would I be safe to assume that cutting the capilllary tube and slipping the new threaded fitting off and putting the old threaded fitting on would not be a good idea? what is inside the capillatry tube?

 

[supergrumpy]

I hope you are joking

capilary tube carries just the right amount of some sort of magic fluid/gas/something from the bulb up to the Bardon tube inside the gauge, when bulb gets hot this magic stuff expands and the gauge then indicates this expansion

cutting the tube would disturb this calibration

 

[Bob]

"what is inside the capillatry tube"

Typically, ether.
Mech temp gauge

 

[MF135Detroit]

Get a universal heat gauge from Advance Auto or some auto supply. I had same problem on 72 MF 135. Drove me nuts. 2" Universal gauge from Advance Auto fit perfectly on same model with Continental engine on 135. The stem was the problem...would not allow the threads to seat. Works fine for over a year.

 

[ampster63]

Thanks for the help