Excess Ink Dripping After ET-8550 CISS Conversion? Here's What You Need to Know

Customer Question:
After converting my Epson ET-8550 to a CISS (Continuous Ink Supply System), I’m noticing a significant amount of ink dripping during nozzle checks. I’ve cleaned the printhead and all the dampers, but the problem persists—ink is pouring out everywhere. Could the dampers be bad, or am I doing something wrong?

Answer:

What Causes Excess Ink Dripping After CISS Installation?

From your description—heavy ink flow, dripping during nozzle checks, and general flooding—it sounds like your system is either over-pressurized or has one or more points of failure in the ink flow regulation. Let’s explore each possibility:

1. CISS Tank Height and Ink Pressure

Gravity-fed systems, such as CISS, can easily become over-pressurized if the tanks are placed too high above the printer.

• Solution: Make sure the CISS tanks are level with the printer’s printhead (typically level with the base of the printer). If they are elevated, gravity will cause ink to flow into the printhead uncontrollably, even when it’s not printing.

2. Dampers May Be Failing or Saturated

Even if you’ve cleaned them, dampers can fail in subtle ways, like sticking open, flooding, or losing their sealing ability.

• Symptoms of Bad Dampers: Ink dripping during idle time or nozzle checks, no resistance when performing suction tests.

• Solution: If in doubt, replace the dampers. It’s a relatively low-cost fix that can eliminate a common failure point.

3. Loose Tubing or Air Leaks

Any air leaks in the system will compromise pressure regulation and may create a siphoning effect, allowing ink to flow through uncontrollably.

• What to Inspect:

  • Tube-to-damper connections: Are they tight and sealed?

  • Tube entering the printhead: Is it securely in place?

  • Tube integrity: Are there any cracks or kinks?

4. Test the Capping Station & Dampers with a Suction Test

Here’s a helpful diagnostic step:

• Park the printhead on the capping station (turn the printer off and on, let it reset).

• Use a syringe on the waste line and draw 1.5–2 ml of air.

• What you should feel: Light resistance and a “crinkle” sound from the dampers.

• If instead, you draw ink with no resistance, that indicates the system is unsealed—likely through damaged dampers or a broken cap seal.

5. Printhead May Be Oversaturated

If ink is gushing out even during basic nozzle checks, your printhead may be internally flooded.

• Fixes to Try:

  • Let the printer sit unplugged for 24 hours with the printhead parked. This allows excess ink to settle or drain.

  • Gently flush the printhead with cleaning solution using the proper tools. Avoid overdoing it—too much pressure can damage micro-channels.

Additional Notes

In CISS conversions, even a small misalignment or pressure imbalance can snowball into significant ink flow issues. The ink system in the ET-8550 is sensitive, and it’s crucial to strike the right balance between gravity, flow resistance, and sealing at every connection point.

Addressing printer issues can be tricky, especially with hardware modifications like CISS systems. Because these are hands-on problems, we can't provide direct remote troubleshooting or one-on-one repair guidance. However, we do offer in-person printer repair services (https://bchtechnologies.com/printer-repair-service) at our local diagnostic facility. Please note that due to high demand, our service works on a first-come, first-served basis, and turnaround times may be a few weeks. While our pricing isn’t the lowest, we provide expert care for complete printer repairs or component-specific fixes. If you're looking to troubleshoot independently, we strongly recommend checking out our YouTube channel homepage (https://youtube.com/@bchtechnologies). Use the search icon next to the “About” tab to find videos specific to your issue. Given our extensive library of videos spanning nearly a decade, this is the most efficient way to locate targeted help.

Thanks again for your question and support—we’re rooting for your successful repair and always happy to hear from you!