Açıklama
On the 850 and 870 the cooling fan is driven by a pump that is one size up from the ZX470’s, and the machine’s heat load is very different. These are quarry and heavy earthmoving tools running eight to twelve hour shifts with a full radiator face of dust. The fan pump is not a peripheral part on a machine like this; it decides whether the hydraulic oil stays inside the temperature band where seals and viscosity survive.
What the K5V80S class means
Kawasaki’s K5V range sits above the K3V in its open-circuit swash-plate family. For the 80 size the published catalogue figures are a geometric displacement of 80 cm3/rev, rated pressure 34.3 MPa with peak 39.2 MPa, maximum self-priming speed 2,460 rpm and maximum speed 3,000 rpm. Rated pressure is the level at which the guarantee of performance and service life applies, so a fan circuit that spikes above it routinely is a circuit with a control problem, not a pump that needs a bigger rating.
The K5V80S designation breaks down as the 80 size in the single-pump configuration, since Kawasaki uses S for single, DT for tandem, DP for parallel, H where a centrifugal impeller pump is bolted on and P where a power take-off is fitted. The relevant question on a Hitachi fan drive is usually what is bolted behind the main unit, because the charge pump and the control combination change the assembly without changing the mounting faces.
Fitment
Supplied for Hitachi ZX850-3, ZX850-3F, ZX850LC-3-DH, ZX870H-3, ZX870H-3-HCMC, ZX870H-3F, ZX870R-3 and ZX870R-3F. Those sub-type suffixes matter: the H, R and LC variants differ in counterweight, boom and cooling package, and the HCMC suffix marks a specific market build. If your plate carries a different number from 4635787, send a photograph rather than guessing at a cross-reference, because the -5B and -5G machines use a later fan pump assembly again.
A note on the photographs in this listing
We would rather raise this ourselves than have a buyer find it. Fan pumps in this family are photographed on the bench in batches, and pumps of the K3V63 and K5V80 sizes are physically similar enough that a housing cast marking can disagree with the folder it was filed in. The images used here show the mesh-shaft-guarded assembly with the charge pump fitted, which is the configuration we ship against 4635787. Before your order is packed we photograph the actual unit, including its nameplate, and hold the shipment until you confirm that plate. If the plate on your machine disagrees with ours, we will tell you before it ships, not after.
Diagnosing the fan pump on a heavy machine
Heat on a ZX870 has more candidate causes than heat on a 20 tonne machine, so work in a sequence instead of replacing parts in order of suspicion:
- Confirm the operator’s complaint with data. Log coolant and hydraulic oil temperature at low idle and high idle under load. On Hitachi’s twin-fan -5G machines the system varies fan speed from both temperatures, so a divergent pair of readings points at the control input rather than at the pump.
- Check the simple things with the engine off: core face blocked between the fins, fan blade damage, and the reverser mechanism.
- Measure delivery. Our fan pompası teşhis kılavuzumuz covers flow and delivery pressure tests; Hitachi’s own technical manual for the -6 series lists the same checks as fan pump P-Q diagram, fan pump flow rate measurement and fan pump delivery pressure.
- Test the control signal before condemning the pump, using the regulator diagnosis and adjustment procedure.
- Inspect what drives the pump. A worn drive gear or a failing transfer case starves a good pump, and the transfer case article ve drive gear inspection guide cover both.
Fitting rules that apply to any replacement
Fill the casing with clean oil before the first crank. Route the case drain to tank with no restriction, keeping within the published 0.1 MPa normal and 0.4 MPa peak limits for this size band. Change the return filter element, and hold cleanliness at NAS 1638 class 9, which is ISO 4406 18/15, with a 10 micron return filter and an 80 to 150 mesh suction strainer. Bleed the circuit with the fan restrained and confirm rotation direction before the guard goes back on.
The motor this pump drives is a separate item: see our 4634947 replacement fan motor for the -3 class machines. The wider Hitachi range is under Hitachi parts ve hi̇droli̇k fan motoru.
New aftermarket units carry a three to six month warranty as printed on your proforma invoice, minimum order one piece, wooden case packing as standard, and around 500 pieces a month off this line.
