ZD1211 Coolant Overflow Bottle Cap Question

Loremaster72

New member

Equipment
B3000, Loader, MM Mower +
Sep 21, 2019
6
1
3
Bolivar, OH
My mom has a ZD1211 that's several years old, enough to have gone through the coolant cap recall and all that. I replaced the thermostat on that machine last year, too. Twice now, once last year and once this, the coolant reservoir bottle cap that the overflow hose connects to has popped off, once ending up down and destroyed (melted), the other time only having minor damage. She's now secured it with a zip tie so it can't go anywhere if it does pop off again, and it does pop off every mowing or two. What's bugging me is that when I look up the parts breakdown, both the old and new reservoir bottle caps are listed as discontinued and there is no replacement (K2581-85272 is the latest part #).

When we noticed that last year, we went down to our local dealer and bought up the 3 spares they had in stock (we needed one to replace the destroyed one mentioned previously). I just looked again and still I'm not seeing any sort of replacement listed. The machine is too new to think they'd just say it's out of service, especially over a small plastic part like this. I would have expected to see a service bulletin and maybe a new reservoir interchange, more expensive but fixing the problem permanently. Does anyone have any insight here? The local dealer that originally sold us the machine didn't seem bugged by this, so they aren't much help.
 

grandpa_e

New member

Equipment
MX5400, ZD1211, BX23S, BX220
May 13, 2026
8
4
3
Louisiana
My mom has a ZD1211 that's several years old, enough to have gone through the coolant cap recall and all that. I replaced the thermostat on that machine last year, too. Twice now, once last year and once this, the coolant reservoir bottle cap that the overflow hose connects to has popped off, once ending up down and destroyed (melted), the other time only having minor damage. She's now secured it with a zip tie so it can't go anywhere if it does pop off again, and it does pop off every mowing or two. What's bugging me is that when I look up the parts breakdown, both the old and new reservoir bottle caps are listed as discontinued and there is no replacement (K2581-85272 is the latest part #).

When we noticed that last year, we went down to our local dealer and bought up the 3 spares they had in stock (we needed one to replace the destroyed one mentioned previously). I just looked again and still I'm not seeing any sort of replacement listed. The machine is too new to think they'd just say it's out of service, especially over a small plastic part like this. I would have expected to see a service bulletin and maybe a new reservoir interchange, more expensive but fixing the problem permanently. Does anyone have any insight here? The local dealer that originally sold us the machine didn't seem bugged by this, so they aren't much help.
I just picked up a 2022 ZD1211 and when I got it home the coolant overflow cap was popped off. I noticed that when opening the hood it rubbed the overflow tube enough to pop the cap off. I slightly re-routed the tube so that the cap was turned about 45 degrees front left for the tube to run a little further from the hood. So far it hasn't popped off again. You could give that a try.