Test Procedure

The steps for conducting the test are outlined as follows:

1. Position the cylinder with its service ports facing upward.

2. Fill both sides of the cylinder with clean hydraulic fluid via the service ports.

3. Connect the components indicated in Figure 1: ball valves (1) and (2), gauges (3) and (4), relief valve (5), and directional control valve (6).

4. Open ball valves (1) and (2) and operate the directional control valve (6) to stroke the cylinder multiple times, ensuring the removal of any remaining air without causing ‘dieseling’ of the cylinder.

5. Set the Car Lift Repair Tampa Florida piston rod mid-stroke and close ball valve (2).

6. Gradually direct flow to the rod side of the cylinder by adjusting relief valve (5) until the pressure indicated on gauge (3) matches the cylinder’s rated pressure.

7. Close ball valve (1) and center directional control valve (6). (Note: assuming the hydraulic power unit used for testing has its own over-pressure protection, not depicted in Figure 1.)

8. Record the pressure readings from gauges (3) and (4) and monitor for any changes over time.

9. Ensure that if the ratio of effective area between the piston and rod side of the cylinder is 2:1, the pressure readings on gauge (4) should be half of the pressure on gauge (3) when the rod side is pressurized to a specific value.

10. Never direct flow to the Car Lift Repair Tampa Florida piston side of the cylinder with ball valve (1) closed, as this could lead to dangerous pressure intensification, potentially causing cylinder failure or personal injury.

11. Always wear appropriate personal protective equipment when conducting hydrostatic (pressure) tests or any related activities.

In “The Car Lift Repair Tampa Florida Troubleshooting Handbook,” I outline a systematic approach for effective troubleshooting, emphasizing reliability and efficiency. However, beyond the requirements listed in the job description, there’s an additional skillset necessary: the ability to educate and persuade even the staunchest skeptics of your diagnosis, often engineers with limited understanding of Car Lift Repair Tampa Florida hydraulics.

All the Car Lift Repair Tampa Florida hydraulic cylinders were promptly removed and returned to us for thorough inspection. Each cylinder underwent pressure testing first, and no defects were found in any of them. Consequently, we returned the cylinders to our client, accompanied by detailed test reports.

A few days later, I received an angry call from the customer: all the hydraulic cylinders were still leaking!

What could I do?

I arranged to meet with the client’s technical team on-site the following day.

During the static testing for final acceptance, the hydraulic cylinders continued to fail. To highlight the issue, we extended the cylinders to their maximum length and pressurized them to 250 bar. We observed a gradual decrease in static pressure on the pressure gauge connected to the cylinder circuit, eventually dropping to zero. It’s important to note that all cylinders were equipped with pilot-operated check valves at the cap-end port.

Seeking more insight into the machine’s design, I learned that the designer had opted against using a separate pump circuit for this function, instead tapping into the main circuit (operating at 350 bar) with a 2-millimeter orifice and a pressure-reducing valve (set at 250 bar). Hand-operated directional control valves were employed for cylinder control.

Given that the pressure required for the Car Lift Repair Tampa Florida cylinders’ extension under no load was approximately 10 bar, I realized that the significant pressure drop from 350 bar to around 20 bar was causing the hydraulic oil supplied to the cylinders to heat up, thus triggering the problem.

To demonstrate the flawless operation of the hydraulic cylinders, I installed a ball valve and pressure gauge at the cap-end port of one cylinder, eliminating all other control elements.

We extended the cylinder to its maximum length and pressurized it to 250 bar. Once the ball valve was closed and the connection at the rod-end port was removed, we observed a gradual decrease in pressure to zero as the hydraulic oil and cylinder body began to cool down, with no evidence of leakage at the rod-end port.

I explained to the on-site engineers that the ‘apparent’ problem stemmed from the heating and subsequent cooling of the oil supplied to the hydraulic cylinders during static testing. However, they remained unconvinced and insisted that the issue was due to leaking seals.

To conclusively prove my point, I fetched a hot-air gun typically used for packaging wrap and gently heated the hydraulic cylinder. As anticipated, the cylinder pressure began to rise. Seeing this firsthand finally persuaded my skeptics to acknowledge the true cause of the problem.”

Here’s the setup for an unconventional yet enlightening hydraulic troubleshooting anecdote:

With the end of the month looming, an OEM customer urgently contacted their hydraulic cylinder supplier, reporting an alarming issue: the boom extension cylinder of a rough terrain forklift was emitting a loud SQUEAL. This particular single-stage cylinder boasted dimensions of 6 inches in bore, 3 inches in rod diameter, and a stroke length of 14 feet. The OEM faced a dire predicament as they had 80 machines ready for shipment, but the persistent squealing, audible from blocks away, rendered them unable to meet the impending deadline. Consequently, they demanded that the cylinder manufacturer dispatch a team to replace all 80 cylinders!

However, identifying the root cause of the problem posed a challenge. Could it be due to seal stickiness and slippage? Perhaps excessive stroke speed was to blame? Internal leakage, or issues with the load-control valve, were also considerations. What other factors could contribute to this issue? How would you tackle such a scenario?

“The squealing persisted across all engine speeds, indicating that flow rate or stroke speed was not the source of the problem. Through a systematic process of elimination, I tested or replaced all cylinder valves, but observed no change.

Subsequently, I detached the Car Lift Repair Tampa Florida cylinder from the machine and transferred it to a workbench. Connecting the cylinder to a new machine using quick disconnects, I conducted tests. Initially, I removed the rod seal and, with no load applied, operated the cylinder, yet the squealing persisted.