D8R dozer 7xm00754. Took valve cover off to look for fuel leak, turned key, saw the mist confirming probable leak.. turned engine off within 5 seconds and now the solenoid for the starter winds loud and fast. Checked each of the 4 batteries individually from positive to negative post, got 12.5-6v each. I beat the solenoid a little with a wrench, no luck. I took the wire off the solenoid and put back on, no luck. With the master switch off I had the key in the start position, turned master key on and still just the solenoid winds up, nothing attempts to start. Today I'm going to try to see if there's a short in a wire. Hoping someone can help me locate where the starter relay is and which wires I should be diagnosing. If wires seem fine, it would either be the relay or the solenoid? How can I determine which is the culprit? Thank you!
What you are describing indicates a (failed) solenoid that isn't pulling the starter drive gear into the flywheel ring gear.
In this case, take the solenoid off and get a new one? Time is of the essence this one. 30-50 trucks delivering dirt every day then start a commercial job in 1.5 weeks.
From the description you definitely don't think it could be started relay or short? By the way the batteries are not low. Checked each one individually and got 12.5v.
It could be several things. But you are describing is classic description of a stuck or broken solenoid. I don't know anything about the starter wiring for a D8K. You could remove the starter and hook up some jumper cables to it and check it. Have it securely anchored because there is a lot of momentum involved if the solenoid does in fact move the Bendix drive ! If you are not comfortable doing that, take it somewhere that can test it. Hopefully that is what is wrong with it. If it isn't you will have eliminated the possibility that it is a problem with the starter. I ran dozers on hundreds of truck dump sites and I know the panic situation you are in. I always carried a set of new Cat fuel filters in my truck. More than once that prevented me from shutting down an entire excavation operation because of a dead dozer on the fill area.
I removed the wire from the ignition relay and it stayed on so that showed the solenoid was bad. Removed starter, took off solenoid and opened. It was welded together. Popped it off with my finger, now I have a **** replacement after I clean the contact areas. Dozer is running great. Continued looking for fuel leak to crank case, no leaks detected. Might be The junction where the lines connect from outside the block to inside the block or the fuel pump. For now I'll take another oil sample and continue running until I can fiddle around with it some more. Everything else in the engine looks great no loose components nothing jiggling. Definitely love this model.
**** ???? S##t hit the fan ?? I don't understand your comment. I'm glad you have the tractor running. You had best get a new solenoid on the way. Cleaning the contacts is a very short term fix.
I got a new solenoid and replaced it. The old one can be cleaned and emergency part for in the field.