Frequent Pressure Disc Blowing? Engine Bogging? US Jetting Shows the Real Cause.
If your jetter is frequently blowing pressure discs or the engine is bogging down, this video walks you through the most common causes — and how to fix them. Over‑pressurization is the root issue, and on Tier 4 engines, the system will automatically protect itself by reducing RPM or shutting down power. On jetters with Tier 3 engines, the pressure disc will automatically blow.
In this US Jetting troubleshooting guide, we explain why this happens, what to check first, and how to prevent it from happening again.
Common Causes of Over‑Pressurization
This video covers the most frequent issues that lead to disc failures or engine bogging:
- Mismatched nozzle setup
- Blocked or undersized nozzle orifice
- Kinked or restricted jetting hose
- Bypass valve not opened enough If you’re running a US Jetting 4018, your nozzle must be drilled for 4000 PSI at 18 GPM. A mismatched or restricted nozzle will immediately cause the pump to exceed its rated pressure.
Correct Operating Parameters (JMS Elite)
To avoid over‑pressurizing your system, your control panel should read:
- Water Pressure: 1000–1500 PSI
- Preset 4: 4000 PSI
- Engine RPM: ~2050
Some brand‑new nozzles are drilled slightly smaller with the expectation that they’ll open up over time. If that’s the case, open the bypass valve to relieve pressure until the nozzle seats properly.
What You’ll Learn in This Video
- How to identify the cause of pressure disc failures
- Why Tier 4 engines bog down under excessive load
- How nozzle size affects pump pressure
- How to adjust the bypass valve correctly
- How to prevent over‑pressurization in the future
Need Help or Have Questions? Our tech support team is here to help. Contact US Jetting at 1-800-JETTING or visit USJetting.com for personalized assistance.
