Overview
12 volt solenoid valve for HydraMaster truckmounts. HydraMaster part number 000-169-120, listed as Valve, Solenoid 12 Volt.
One part, three different jobs. Which job it is doing on your machine determines where you will find it, and it is worth knowing before you go looking.
Where it is fitted
Incoming water solenoid
Fitted to all HydraMaster machines with electric incoming water control. It opens and closes the fresh water feed.
Hot water dump solenoid
- Boxxer 427
- Crossfire 3.7, Crossfire 4.2, Crossfire 4.4
- SpitFire 4.0
APO priming solenoid
On machines with a belt-driven automatic pump-out:
- CDS 4.6, CDS 4.8
- Javelin
- MAXX 450D, MAXX 470D, MAXX 550
Diagnosis
A solenoid fails in one of two ways, and they present very differently. Failed closed and the circuit it feeds stops working — no incoming water, no dump, no APO prime. Failed open and it passes continuously, which shows as water where it should not be, or an APO that will not stop.
Before condemning the valve, check that it is being told to open. These are 12 volt devices driven through the machine's control circuit, so a dead relay or a broken feed presents exactly like a dead solenoid.
Related parts
- HydraMaster Relay Switch 12V (157-022) — drives circuits like this one; swap-test it before replacing the solenoid
- Regulator 3 Amp 1000 PIV Diode (135-051)
- CAT Thermo Valve 180° (169-011)
Frequently asked questions
Is it the same solenoid for all three applications?
Yes — HydraMaster specifies 000-169-120 in all three roles. What differs is where it sits and what it controls.
Mine passes water with the machine off. Is that the solenoid?
Usually. A solenoid held open by debris on the seat will pass with no power applied. Sometimes it clears; a scored seat will not seal again.
How do I tell a dead solenoid from a dead circuit?
Check for 12 volts at the solenoid while the function is called for. Power present and no movement is the valve. No power is upstream — relay, switch or wiring.
Not sure which of the three your machine uses? Send us the model and serial number and we will confirm before you order.
