When to overhaul and when to replace a pump?
A practical assessment based on the damage pattern, machine hours, delivery time and total cost.
With an Eaton Heavy Duty or Medium Duty hydrostat, we are sometimes asked: overhaul or replace? Our answer starts with another question: What is the maximum time your machine can be out of action?
In the season: exchange
An exchange unit from stock is fitted quickly. We then overhaul your own pump or motor without rushing. If you want it back, that is possible; otherwise it goes back into stock.
Outside the season: overhaul
Then there is time to open the unit, measure it and replace only what is worn: worn shaft splines, pistons, the rotating group, seals.
Buying new
That is rarely necessary. Only if the housing itself is damaged is a new unit the best choice. Unfortunately, that does happen when the hydraulic pump system gets too little maintenance: the wear then continues into the housing itself. Good maintenance, with clean oil and a new filter on time, helps to extend its service life.
What we come across
Scratches on the pistons from dirt in the oil. That is why we always replace the oil and the filter after an overhaul.
We also check the bearings. On these needle bearings from a pump you can see dark marks and small pits on the outer ring: the metal is flaking off due to fatigue. We always replace a bearing like that during an overhaul.
And then the shaft itself. The screwdriver points to a wear track around the shaft, at the point where the seal runs. A new seal on a track like that will keep leaking. Replacing the shaft is then the only right option.
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