Quest hydro problem

[caduke]

Noticed last year the hydro oil in reservoir was gray. Don't know how but dealer said water got in system. Changed oil and both filters. You can cut for about 45 minutes and starts making wining noise when turning and pretty soon no steering at all. You can shut mower off and let cool and go back to cutting for 15-20 minutes till you have to shut off and let cool again. Any suggestions? Thanks in advance.

 

[mechanic mark]

What color is hydro oil now?

 

[tom3]

I don't think gray oil is from moisture. Possibly from metallic particles that have spalled off and gotten sheared into powder and suspended in the oil. Might do another oil change with some heavier oil and get some more use out of it.

 

[caduke]

Oil looks normal now. Was going to drain new oil out again and replace filters again and see if any difference.

 

[cruzenmike]

This is a tricky problem. Water in an oil system will usually make the oil cloudy, milky or white. The gray color as mentioned earlier seems to be indicative of some type of metal fragments in the oil. When you say that the oil looks normal now, is that light yellow, brown, black, blue? In my Exmark I was using their genuine hydro oil and it was green in color. Some hydrostatics were filled with a synthetic motor oil from the factory. It is not a cheap attempt at a fix, nor would having to replace both drives in your mower, but you might want to change the oil and filters again, flushing the system by changing, letting run for 30 minutes with the parking brake on, and then changing again. This will allow the fresh oil to get up to temp and pull any contaminants through the filters and catch them. Then another set of filters and oil will get you back up and running.

None of this will matter if there has been in fact some damage to the drives. Since I suspect that this system utilizes separate pump/motors with one single, shared oil reservoir, then the easiest and cheapest option at this time is to work with the fluid and filters. Check for leaks in the entire system as well, since there will be some hoses and clamps from the reservoirs to the drives and back. And as always, ensure that everything that you will be touching or working on is CLEAN!! Inexperienced people accidentally contribute to their problems by introducing contamination to the system when checking or adding oil, or when changing the filters.

 

[caduke]

I originally said the oil look gray but being color blind I see the confusion. The oil was similar to chocolate milk, so I guess it was really brownish. I raised the mower and opened both plugs and drained the oil from the mower, removed both filters. I installed two new filters and filled the reservoir with 4 quarts of the "Exmark Hydro Oil" The new oil is black/bluish. This oil is $16.00 a quart, but I don't know of a cheaper oil that would do just as good. Anybody know of some please let me know. Anyway, I'm going to try changing oil and filters again as the steering pumps cost 800.00 and 900.00 each to replace. By the way, it is a 2016 model Quest.

 

[Mr..Jeff]

I know am late but, exmark makes 3 different types of hydro oil. One red, ( one green for the diesels) and a clear colored one. The right oil makes a difference. The gray color could be metal from a bearing? It only makes noise when it heats up? You could take that hydro off the machine and inspect the fan on top and hydro and the pully underneath the hydro? Then look inside the hydro if you get the pully off to see if there is any damage inside the hydro reservoir? If am to late? I hoped you figured it out. Cheers Jeff