Overview
12 volt relay switch, listed by HydraMaster as Switch, Relay.
Used throughout the machine's electrical control. A failed relay usually presents as one circuit dead — pump clutch, APO or a solenoid — while everything else works normally.
Where it is fitted
- Electrical Control Panel Assembly — 6 per machine
- Dura-Flow APO pump assembly — 1
Six in one panel is worth knowing: if you are diagnosing an intermittent electrical fault, swapping a known-good relay between circuits is the quickest test available.
Verified fitment — current machines
- Boxxer 318HP — Frame Assembly (Figure 9-9), 1; AWDS Universal Kit Assembly (Figure 9-33), 1
- TITAN 575HP — listed in the machine parts book
- TMTG4000 — Frame Assembly (Figure 9-12), 2
CCW's records list six in the electrical control panel on earlier machines. The current parts books show smaller counts spread across the frame assembly and the AWDS kit. Relay counts vary by machine and by fitted options, so count what is in your panel rather than ordering to a figure.
Verified from the HydraMaster parts books: Boxxer 318HP MAN-46586 Rev C and TMTG4000 MAN-47717 Rev B.
Related parts
- Regulator 3AMP 1000 PIV DIODE (135-051)
- Valve Solenoid 12 Volt (169-120)
- HydraMaster Recovery Tank Float Switch (157-0801)
Frequently asked questions
One circuit is dead and everything else works. Is it the relay?
Very often. Swapping a known-good relay between circuits is the quickest test available and needs no instruments.
Are they all the same relay?
Within a panel, generally yes — which is what makes the swap test work. Confirm before mixing across machines.
Should I keep a spare?
It is a low-cost item on a machine that stops earning when a circuit drops out. Most contractors carry one.
Send us your machine model and serial number and we will confirm the relay count for your panel.
Identifying the right part
HydraMaster truckmounts share many components across models and across production years. Part numbers in the CCW catalogue are the HydraMaster part number with the 000- prefix removed — this item is HydraMaster P/N 000-157-022.
If you are ordering for an existing machine, check the model and serial number on the data plate and send them to us. We will confirm the part against the parts list for your machine before you order.
Confirmed against the HydraMaster Boxxer 421 machine assemblies and parts lists (drawing set D-5057 / D-6861). Fitment to other HydraMaster models has not been verified from a parts list — ask us if you are ordering for a different machine.
Hydramaster Relay Switch
TITAN 425 fitment
Named in the parts listing for the HydraMaster TITAN 425:
- Electrical Panel Assembly (610-011-728) — 1
- AWDS Universal Kit Assembly (000-079-220) — 1
Verified from the HydraMaster TITAN 425 parts listing, MAN-47791 Rev A.
