Installation of MotorMeter

[Ron Zeraldo]

Hi, I am installing a Boyce MotoMeter into the MGTC Rad Cap & want to make sure that I have the black rubber seal (disc) in the correct position. Should it go between the Rad Cap & the MotoMeter or on the underside of the Rad Cap with the Brass Nut tighten up against it? (to me it makes sense to have it on top of the cap)....I have seen the rubber disc installed both ways! Also, which ‘face side’ of the meter should be toward the driver? There seems to be much controversy on this as well.



Thank you for your input!



Ron

MGTC5911

[Steve Simmons]

I'm not sure it matters which side the rubber is on, so long as it is held firmly in place by either the flange on the motometer body, or the washer under the nut. The system is under no pressure so it's only keeping splash and vapor from coming out.

The part that reads the temperature is supposed to face the driver. Turning it the other way would render the gauge useless.

[Ron Zeraldo]

Thanks for the reply Steve. Yes what you say makes sense...however, my new Motometer did not come with a washer so securing it on the underside of the rad cap with just the brass nut against the rubber seal wouldn't tighten it correctly, therefore figured it must go on top of the cap under the meter. As the temp rises I'm sure there will be pressure in the system (low) so a proper seal needs to be made...as coolant could travel up the threaded shaft & would get past the rubber seal if installed underneath the cap. This has all come out with various responses received & some additional legwork I did on other sites. As far as which side should face the driver...again much controversy, some are saying the temp. is read on both sides the small circular side is magnified & thus can be read from the driver's seat...the side with the graduated markings cannot be read & can only be seen when looking at from an angle! A simple thing with so much opinion! I have emailed Boyce Motometer for their thoughts! I will let the group know what I find out!

[Steve Simmons]

There will never be any pressure because the overflow tube is open to atmosphere.

As far as one side being magnified, etc., I'm sure there are peculiarities with each brand or model. But the bottom line is, whatever makes it easiest to read from 6 feet away would be the best way to mount!

[Ron Zeraldo]

Sorry, if the rad gets into a full over heating situation (boiling) the overflow tube will handle most the expanded fluid but there will still be some pressure on the underside of the cap...hence why bother with the rubber o-ring that seals the cap to the rad neck? I will let you know what Boyce has to say!

[Steve Simmons]

I think the pressure would be quite minimal considering the size of the overflow tube, but sure in a severe boiling situation I suppose there could be something there. The rubber o-ring prevents coolant from escaping even when temperatures are normal though. I had a situation once where the cap wasn't flush to the o-ring and ended up with drops of coolant coming out at speed.

[Ron Zeraldo]

Yes minimal pressure...but pressure will prevail! I know this question on the Motometer seems simple when compared to the array of more complex issues that can arise when restoring a TC....I have been there & spent endless hours understanding & educating myself, but I am very anal when it comes to getting things done right the first time! Thanks for your input as always your comments are more than welcome & I hope when my wife & I travel to So Cal to stay with friends that we will have the opportunity to meet.
Be Well!
Ron