Overview
Seal kit for a triplex pump. HydraMaster part number 000-078-141, listed in CCW's records as Kit, Seal Triplex Pump.
The high-pressure seals run on the plungers and are the wear item that determines how long a triplex pump holds pressure. They are a service part, not 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. Several different triplex pumps appear across the HydraMaster and Prochem ranges, and their seal kits are not interchangeable.
Send us the make, model and serial number from your pump before you order and we will confirm this is the right kit. We would rather check than have you strip a pump twice.
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
Seals and valves are usually done together — one strip-down rather than two.
When to fit seals
The symptoms are all pressure symptoms: pressure that will not reach the set point, pressure that holds at rest and falls away under trigger, or a pump that has become noticeably noisier under load.
Water at the weep holes between the water end and the crankcase is the unambiguous sign. Do not keep running a pump that is weeping — the next thing to happen is water in the crankcase, and that turns a seal job into a pump.
Fitting advice
Inspect the plungers before you fit new seals. Scoring, pitting or a dull worn band will destroy a new seal set quickly. Replacing seals twice costs more than replacing a plunger once.
Work clean. A single piece of grit under a seal lip is a leak.
Follow the pump manufacturer's torque figures on reassembly — uneven clamping distorts the seals and reproduces the fault you set out to fix.
Change the crankcase oil at the same time, particularly if it has gone milky.
Frequently asked questions
Will it fit my pump?
Ask us first. Triplex seal kits are not interchangeable between pump makes and we will not claim fitment we have not verified.
What is in the kit?
Not itemised in the documentation we hold. Ask us before ordering.
My pump oil is milky. Is this the fix?
It is usually part of it, but check the plungers for scoring and change the oil as well.
Should I do valves at the same time?
Usually yes — see 078-139.
Send us the make and model of your pump, or a photo of its data plate, and we will confirm the correct kit before you order.
