April 23, 2004
I fixed the lawn tractor's radiator
This afternoon I replaced the radiator on our Honda 4518 lawn tractor. It had spontaneously sprung a leak in the last few weeks. We tried fixing it using a leak-sealing liquid that is poured into the radiator, but the hole was too large. I ordered a new radiator, which came to $211, at a local equipment dealer that handles Hondas. I also replaced the rubber hose to the overflow container, which had cracked. 
A consequence of the radiator hole was that the engine block became very hot when I was mowing the lawn — so hot that a plastic timing belt cover melted. I ordered a new cover for $76, and I need to install it, which will be a pain, as a drive shaft goes from the engine through the plastic cover to the hydraulic transmission.
Posted by seander at April 23, 2004 12:14 AMI had the same problem several years ago with my 4518. I took the radiator to a radiator shop and had it recored at a cost of $20.
The design of the grille opening and fan direction contibute to occasional over heating as the radiator front becomes blocked with fine thatch.
Posted by: j d smith at June 20, 2004 06:22 PM(Wow my first comment from a stranger!)
We tried to replace the timing belt cover a few weeks ago, and could not. We think removing the engine may be necessary, so we have postponed it until after the grass mowing season ends. I don't think it matters.