Hello! My husband and I purchased a 2000 Mauldin MG618 motor grader. The problem we have with it is, after about 45 mins of running, it WILL NOT go up even the smallest incline. Shut it off for about 20mins, fire it back up, and it has no problem going up an incline like a bat out of hell. As long as it is on level ground, it runs all day like a champ. We have changed the hydraulic fluid (it was black!), as well as ALL filters, yet this problem still persists. Any ideas as to what the problem may be/where or what we should look at next? Also, we have been unable to find a service/ manual on this thing (only parts). Anyone know where we could find one? I've tried their website, which is where we downloaded the parts manual, but there is no service/owners/operations manual to be found. Any help would be appreciated! Thanks in advance!
They have a technical help request form on the website, that's a good place to start. Some other guesses: they didn't make the hydrostatic drive system, find out what make it is and look up how to diagnose it based on that. Say it's a Chevy XYZ hydrostat, find troubleshooting for that, not a Mauldin. Any chance there's a screen that you missed when you changed the filters and fluid? And what did the inside of the old filters look like? Checking the fluid temperature and pressure would be the next step.
We have two of their maintainers, a 2011 and a 2014. They are a similar design to our alitec, and Puckett. Anyway our alitec acted like that when the pump went. On a side note, our Puckett had a second pump off the end of the crank with a rubber coupler from the crank to the pump. Sometimes if the coupler was worn, it would actually slip when it was hot. You could hear the ratcheting sound when it did. Not sure if the larger mauldin has that or not.