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Re: D4G Powertrain oil filter bypass warning light stays on

[ Edited ]

Thanks Chad,My biggest consern was that the hydraulic oil was bypassing the filters. I'm pretty sure its going through the filters . Now I.ll check the wiring again .

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Regular Contributor

Re: D4G Powertrain oil filter bypass warning light stays on

That is good news on the oil analysis, so you need not worry about the light being continuously on, as the problem may be strictly electrical like the tech said.  If a grounded wire in that circuit is causing the problem, disconnecting the two wires to the pressure switches will not make the issue go away, because somewhere in the wire loom exists the grounding issue.  And good luck locating that. 

 

The portion of the wiring loom you could not access - try just moving that part from the portion you could get to and see if the light goes out.

 

I have encountered wire grounding issues inside Cat grader harnesses where it was more expedient to run a completely new ground wire than to enter the wire harness to find the problem.  HTH

 

 

 

New member

Re: D4G Powertrain oil filter bypass warning light stays on

Oil analysis is good. Changed out the two pressure switches and replaced a relay behind the console , but light stays on. Talked to a tech who thought I might have a wire grounding out. I disconected the two wires to the presure switchs and the light stays on. The wiring I was able to trace looked good but I couldnt get to all of it. 

Regular Contributor

Re: D4G Powertrain oil filter bypass warning light stays on

As you probably know, the light illuminates when its sensor detect an unacceptable pressure drop across the hydraulic filter.  I have seen a similar sensor fail in a 12M grader, so that could be the issue with your machine, but it would be best to check the pressure drop with a calibrated gauge.  Also, was an oil analysis performed when the fluid was changed? Just to rule out possible contamination problems.

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D4G Powertrain oil filter bypass warning light stays on

D4G Powertrain oil bypass light stays on. Changed hydraulic fluids and filter less then 400 hrs ago. Dozer has 1600 hrs on it. I changed hydraulic filters again but light stays on. Whats my next step? Change out pressure switch ?