TR4/4A TR4 Oil Pressure Gauge

[MikeH]

Hi All, It seems that my oil pressure guage stays at highest pressure that has been sensed. Will not return to zero whwn the engine is off, or change with RPM's when engine is warmed up. May have messed up installation of oil pressure line, but that seemed straight foward. any thoughts appreciated. Thanks, Mike

63 TR4 Surrey Top

 

[TR4]

Have you tried rapping on the dash beside the gauge? That worked for my Amp gauge when the needle got stuck on one side.

 

[piman]

Hello Mike,

firstly undo the oil line and see if that 'frees' the needle, preferably from the gauge end.
I suspect that the mechanism has jammed however, which will entail stripping the gauge. I don't know if it's possible to dismantle that gauge without removing the needle as if you do it probably will need re-calibration.

Alec

 

[dklawson]

If you don't want to open your gauge up and the above methods don't help... search eBay Motors for Smiths pressure gauges. They routinely for sale at reasonable prices. Find one that looks like yours (focusing on the face). You can always swap the chrome bezel from your current gauge if you don't find a new one that matches exactly.

 

[Geo Hahn]

Shoot, just parted with one on eBay for small money awhile back. As noted they usually go cheap. I would suspect (or hope for) a bit of debris in the line. I have never opened one of these but I think it is not easily servicable.

 

[Marvin Gruber]

Mike,

let me know if you need one, have several.

Marvin

 

[sp53]

Hello yes you should be able to get a good gauge on eBay for 30 bucks or so, or you can send yours to I think it is MOMO or something. They are in New Mexico and Moss has their address in the catalog; I have found them very cool. In addition, I have taken many apart and most the time they just need cleaning up. However, I did have one in which the needle would come lose and then kinda work sometimes that really messed with my head because oil pressure is something, you know, pretty serious.
They come apart kinda weird so be careful. First turn the class off the front then on the back of the gauge can is a nut that holds the guts and needle in place. This nut sits on the feed line and also holds the needle assembly in place. The trick is to back the nut off without letting the feed line wobble because when the feed line wobbles the needle moves and can bend, break, and ect. You need to leave the needle on because it is woven in behind the face indicator. With the nut lose(not off) and the face indicator lose you can slide the face indicator off weaving it through the slot in the indicator face. You can set the mechanical guts on a pencil and slide the can off. I use a fine small soft brush to clean the painted face to remove dirt then clean the metal can. Even if you break one of them it is worth the education to see how the mechanism works.

Sp53

 

[Adrio]

Before jumping to the conclution that the gauge needs to be repaired, I would confirm that the line is OK. I have has a similar "one way" situation with a clutch line. I think the inside of the line gets poor and swells up. The pressure from the engine is strong enough to push past the "flap" but the guage has no pressure (or volume) to speak of to push back past the flap.

Just a thought but this sounds like a hart valve in your oil line /ubbthreads/images/graemlins/smile.gif