Overview
O-ring repair kit for the HydraMaster stainless solution valve. HydraMaster part number 000-078-019, listed as Kit, HM Solution Valve Repair and, in the tool manuals, as Kit, Wand Valve Plunger.
The solution valve is the trigger valve in the wand or tool. It is opened and closed thousands of times a day, under pressure, in hot water — and its seals are consumables, not failures.
What it fits
It services the HydraMaster stainless solution valve (169-058), which is used across the range:
- HydraMaster CDS 4.2 / 4.7 — Kit, HM Solution Valve Repair
- HydraMaster CDS 4.8 — Kit, Wand Valve Plunger
- HydraMaster MAXX 450D / 470D — Kit, H/M Solution Valve
- HydraMaster Crossfire 4.2
- HydraMaster RX-20 — Solution Valve Kit
- HydraMaster DriMaster rotary and upholstery tools
Anywhere a HydraMaster stainless solution valve is fitted, this is the kit that services it.
When to fit it
The classic symptom is a valve that drips after the trigger is released. It is easy to live with and it should not be, because the drip is going onto the carpet you have just cleaned and into the pad you have just set.
The other symptoms are a trigger that has gone heavy or notchy, and weeping at the plunger where it enters the body. Both are the same cause: seals that have hardened or taken a set.
Seals in this service harden from heat as much as they wear from movement. A valve on a machine running high solution temperature will need seals more often than the same valve on a cooler machine at the same hours.
Fitting advice
Depressurise the solution line before you start. This is a valve on a high-pressure circuit and it does not need to be explained twice.
Note the order and orientation of the seals as they come out. Take a photo. They go back in a way that feels right and is not.
Check the plunger and the seat while it is apart. If the plunger is scored or the seat is pitted, new seals will drip again within weeks — at that point you are replacing the valve, not the seals.
Lubricate the new seals with something compatible with the chemistry the valve sees. Petroleum grease on the wrong elastomer will destroy a new kit faster than the job did.
Frequently asked questions
My valve drips. Is this the fix?
Usually. Check the plunger and seat for scoring first — if either is damaged, the valve needs replacing rather than resealing.
Does it fit tools as well as wands?
Yes. The same valve is used in the DriMaster rotary and upholstery tools and in the RX-20.
What is in the kit?
HydraMaster does not itemise the contents in the documentation we hold, so we will not list contents we cannot verify. Ask us if you need to know before ordering.
How many should I keep on the van?
At least one. A dripping trigger valve is the sort of fault that turns a good job into a callback, and the repair takes minutes if the kit is on board.
Not sure whether you need a seal kit or a new valve? Tell us what the valve is doing and we will help you work it out before you order.
