Locating the Flow Control Valve

The flow control valve is built into the valve body on the side of the DC26 pump — the black manifold block between the motor and the reservoir. There are two threaded ports visible on the face of the valve body. The upper fitting is the adjustable flow control valve. The lower fitting is a fixed plug and is not adjustable.

The flow control valve is the upper fitting on the valve body (circled). The lower fitting is a non-adjustable port plug.

Close-up of the flow control valve. The center hex socket accepts a 3/16" or 5mm Allen key. The outer ring is the lock nut.

What the Flow Control Valve Does

On a single-acting (gravity-down) KTI DC26 pump, hydraulic fluid is pumped under pressure to raise the bed. When you activate the lower function, the solenoid valve opens and the weight of the bed pushes the fluid back through the circuit toward the reservoir. The flow control valve is a needle valve in this return path — it restricts the flow of returning fluid, which controls how fast the bed drops.

• Valve turned in (clockwise) = more restriction = slower drop. The needle seats further into the orifice, reducing the opening the fluid passes through.
• Valve turned out (counterclockwise) = less restriction = faster drop. The needle backs away from the orifice, increasing the opening.
• At fully closed (all the way in), the bed will not drop at all — the fluid has no return path. Never operate the pump with the valve fully closed.
• At fully open (all the way out), the bed drops at maximum speed — which can be dangerously fast on a heavy load and may cause slamming and frame stress.

Adjustment Procedure

1. Gather Your Tools

   You need a 3/16" or 5mm hex (Allen) key — the same type used for set screws. If the lock nut has one, you may also need a small open-end wrench (typically 3/4") to loosen it before adjusting. Have a rag ready — some fluid may weep from around the fitting during adjustment.

2. Access the Valve Body

   The valve body is on the side of the DC26 pump. If your pump is mounted inside a toolbox or tongue compartment, you may need to reach in from the access panel. The upper fitting on the valve body face is the flow control valve — refer to the photos above.

3. Loosen the Lock Nut (if present)

   Some DC26 configurations have a lock nut around the adjustment screw. If present, loosen it with a wrench — just enough to allow the inner needle to turn. Do not remove it completely.

4. Make a Baseline Note

   Before adjusting, count how many turns the screw is currently from fully closed (gently turn clockwise until you feel resistance — do not overtighten). Note that count so you can return to your starting point if needed. Most factory settings are 1.5–2.5 turns out from fully closed.

5. Adjust 1/4 Turn at a Time

   To slow the drop: turn the hex screw clockwise 1/4 turn. To speed up the drop: turn counterclockwise 1/4 turn. Make only one adjustment at a time — do not turn multiple full rotations without testing.

6. Test With an Actual Load

   Raise the bed fully and activate the lower function. Observe the drop speed with a representative load — the adjustment behaves differently empty vs. loaded. A properly adjusted valve produces a controlled, steady drop that takes 5–15 seconds to fully lower a loaded bed, without slamming at the bottom.

7. Repeat Until Correct, Then Lock

   Continue 1/4-turn adjustments and tests until you reach your target speed. Once set, re-tighten the lock nut if present — finger tight plus 1/4 turn. Do not overtighten the lock nut, as this can crack the valve body or distort the needle seat.

Frequently Asked Questions