Brown spots in grass after I mow.

[Henry26]

I have a brand new 42" Cub Cadet RZTS mower that I've only used 5 times. Each time I mow, I notice brown spots in my lawn 1-2 days later. These are not scalp spots, but more like something is leaking onto the grass and killing it. The spots do come back after a few weeks so whatever it is, it must not be a lot. I did check for a fuel leak and did not see anything nor do I smell gas. What could be causing these spots and what is the fix?

 

[oregunbota]

Henry26

I have the same thing happening with a new John Deere 300x. After doing some searching on the internet I found this to be a fairly common problem with newer mowers and I found posts on the subject dating back to 2008. I've seen the John Deere x series listed along with Cub Cadet. I think what you will find is the dead grass spots will be where you have stopped for some reason. I first noticed I was getting burnt spots in the lawn where I stopped to clean the mowing deck with the washing system that John Deere uses. John Deere is aware of the problem on their mowers and sells a defector to try and prevent this. I just put one of those deflectors on last weekend but I don't think it is going to work. I can feel very hot air directed straight down under the engine area on my mower.

 

[zzvyb6]

Leaking hydraulic (transmission) fluid.

 

[RG1]

No, it's not a leak. This is fairly common unfortunately, especially with ZTR's since their engines sit on a platform low to the ground in the rear. It usually happens at one or both ends of the muffler, or where the hydro units are parked over the grass, and it doesn't take more than 30 seconds to a minute to do it.

Watering the spots regularly helps them recover faster. I mow for a living, and have experienced this numerous times with more than one ZTR. Enough so, that I don't park or sit the machine where the muffler has a chance to do damage anymore,

 

[GManBart]

No, it's not a leak. This is fairly common unfortunately, especially with ZTR's since their engines sit on a platform low to the ground in the rear. It usually happens at one or both ends of the muffler, or where the hydro units are parked over the grass, and it doesn't take more than 30 seconds to a minute to do it.

Watering the spots regularly helps them recover faster. I mow for a living, and have experienced this numerous times with more than one ZTR. Enough so, that I don't park or sit the machine where the muffler has a chance to do damage anymore,

Wow...learn something new every day here!

 

[RG1]

Wow...learn something new every day here!

When I first started experiencing this problem, I wondered what the heck was going on. Then, after checking the machine out for problems, I noticed that the spots always showed up in pairs, and spaced exactly the same distance apart. As soon as I realized this, I also noticed that it happened anywhere that I had stopped the machine for any reason or amount of time, like stopping to get off, open a gate, and then proceed. By the time I was coming back out through the gate(s), there would be brown spots forming. Suddenly it all made sense- the heat coming off each end of my muffler was doing it. The main body of the muffler was shielded, but the ends were not, and that's exactly where the spots would form, and the damage was done in less than 15 seconds most of the time. I have heard from other LCO's who get the same thing from their hot hydro's.

 

[Ford850]

Have a JD F525 that has this issue. Bought it back in 95 and has done it since day 1. I cannot believe a company would continue to build mowers with such a basic design flaw for this many years. I quickly learned to never stop in the lawn with my, ahem, LAWN mower. Haven't bought a JD since.

 

[RG1]

It's not just JD. Most all of them do it. Plenty of posts about several brands to read on Lawnsite, and some of them are far worse than JD.

 

[emma2000]

I have a 42" Cub Cadet RZTS also, but wondered if any of you have dogs? as they can also cause brown spots in the lawn

 

[square1]

wondered if any of you have dogs? as they can also cause brown spots in the lawn

I was wondering if Henry26 was "marking" his territory while mowing