Also known as the Valmet 8400: for the Valtra 8400 this page lists more than 170 parts such as steering and front axle, electrics and trailer couplings.
Plenty of farmers still call it the Valmet 8400, while other paperwork says Valtra. Either way it is the same tractor from the Mega range, and there are more than 170 parts for it on this page, from makers including GRANIT, Scharmüller, GRAMMER, Walterscheid and DANA Spicer.
Under the bonnet you will find radiator hoses such as the top hose, thermostats with their gasket, alternators and seal kits. If the engine will not reach temperature in winter or runs hot under heavy load, the thermostat is often the first suspect. There are also stop cables for shutting the engine down, seals like the one for the feed pump, O-rings for the differential and repair kits.
The stop cable is one of those parts nobody thinks about until it snaps. If the engine is reluctant to shut off or the handle has to come out further each time, the inner cable is stretching or binding in its outer. Route a new one without tight bends and well away from the hot exhaust manifold, or the same story starts over again soon enough. A few drops of light oil down the outer keep it moving freely.
You can test a thermostat in a pan of water on the stove with a thermometer beside it. It should start opening around its rated temperature and close again as the water cools. When refitting, always use a new gasket and, if there is a small bleed hole, put it at the top. Refill the cooling system slowly and let the engine warm up with the heater valve open so trapped air can escape, then check the level once more after the first run.
Because the same tractor goes by two names, rely on the number on the type plate. If it says 8400, this is the right page. For a clutch plate, compare the diameter and the number of splines, and for a stop cable the length of the cable itself. If a reference number is still readable on the old part, use it as a check.
Within the Mega range these models each have their own page, useful when a second Valtra shares the yard: the Valtra 8050, the Valtra 8150 and the Valtra 8550. Other models from the brand, older Valmet tractors included, are under Valtra parts.
