Overview
Valve kit for a triplex pump. HydraMaster part number 000-078-139, listed in CCW's records as Kit, Valve Triplex Pump.
The valves are what make a triplex plunger pump a pump. They open and close on every stroke, in water carrying whatever the machine has picked up, and they are a service item rather than a failure.
What it fits — please check before ordering
We have not been able to confirm which pump this kit services from HydraMaster's published parts documentation. The part number does not appear in the machine parts lists or the suggested spares schedule we hold.
Triplex is a pump layout, not a model — HydraMaster and its sister brands have used several triplex pumps across the range, and their valve kits are not interchangeable. Fitting the wrong kit means the pump comes apart twice.
Send us the make, model and, if you have it, the serial number from your pump before you order and we will confirm this is the right kit. We would rather check than have you fit the wrong one.
We have raised this with HydraMaster as part of an ongoing parts identification request. This page will be updated when we have their answer.
Related pump service parts
Valves and seals are usually done together. A pump that has run long enough to need one has generally earned the other, and doing both means one strip-down rather than two.
How worn valves show themselves
- Pulsing or hammering that has worsened over time points at valves more often than seals.
- Sudden loss of pressure with no visible leak — check the valves first.
- Erratic pressure rather than a steady decline — a valve held open by debris, or a broken valve spring.
- Weeping at the weep holes — that is seals, not valves.
Fitting advice
Keep the valve assemblies in order and the right way up as they come out. They are not all identical.
Inspect the seats. A pitted seat will not seal against a new valve, and no kit will fix that.
Check the inlet filtration before you close the pump up. Debris in a valve seat almost always arrived through a neglected strainer, and it will happen again.
Frequently asked questions
Will it fit my pump?
Ask us first. We are not going to claim fitment we have not verified, and triplex valve kits are not interchangeable between pump makes.
What is in the kit?
Not itemised in the documentation we hold. Ask us before ordering if you need to know.
Should I do seals at the same time?
Usually yes — see 078-141.
Send us the make and model of your pump, or a photo of the pump's data plate, and we will confirm the correct kit before you order.
