# 7040 allis chalmers dummy light question



## showard8908 (Sep 2, 2011)

I just picked of an ac 7040 to run my discbine and it has been doing a great job. No complaints except there are 6 dummy light ( charging system, oil pressure, trans temp, engine temp, transmission pressure above 1800 rpm, and hydro filter) and the transmission pressure above 1800 rpm light comes on with the tractor up to temp and the engine at lower rpms. I don't know the exact rpm since the tach doesn't work. What does that light mean and should it be on until it's above 1800 rpm?


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## showard8908 (Sep 2, 2011)

I guess I forgot to mention it is a powerdirector trans and it is an early tractor (maroon belly).


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## slowzuki (Mar 8, 2011)

Ask on allis forums, I would guess it's related to the tach being broken.


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## Farmerbrown2 (Sep 25, 2018)

I'm no Allis guy but on John Deere's filter change and correct oil and filter sometimes fixes that problem.


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## HayMike (Mar 22, 2011)

Its OK for that light to come on below 1800 rpm, also when you clutch or shift the PD. I run my discbine w/ a 7045. The tach drives from the alternator AC side. If that output is bad, the tach won't work.

Mike


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## showard8908 (Sep 2, 2011)

Thank you hay mike I'm not concerned with the tach I know when the mower is runNing at speed the light just bothered me not knowing what it's for. Do you know the specific function of the light or just that it is been ok on your tractor like that?


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## bauerd44 (Sep 23, 2014)

Here is the address for the Allis Chalmers Forum. There are knowledgeable people that can get you an answer.

http://www.allischalmers.com/forum/default.asp

Hope you can get some help.


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## HayMike (Mar 22, 2011)

It is the transmission pressure warning light. It is indexed to pressure at working speeds, so if it lights above 1800 RPM, there is a problem. Older tractors are interesting sometimes.

Mike


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## mlappin (Jun 25, 2009)

Just dealt with something similar on a MF8160, new filter restriction/low transmission pressure sensor fixed it.


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## HayMike (Mar 22, 2011)

It is working correctly the way it is.

Mike


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