Hey guys i have a everdigm line pump and one side pushes significantly slower then the other to the point if you dont keep playing with the flow while priming the line when it changes over concrete will race passed the slurry and on the other stroke it will hardly move. Any Ideas? Cheers

You’re describing a classic “one fast / one slow” stroke problem, and the fact that it’s bad enough to outrun your slurry on one side means you likely have a hydraulic/control issue on the pump side, not just a concrete/priming issue.

On an Everdigm line pump, main suspects are:

1. Hydraulic imbalance between the two material cylinders

   • Spool / control block issues: A sticking or partially blocked spool in the main pumping (shuttle) valve or in the speed/flow control to one side can cause one cylinder to get full flow while the other is starved.
   • Internal leakage: If one side’s cylinder or its associated plumbing is bypassing internally (rod seals, piston seals, or check valves), it will move much slower under load.

2. Stroke-change / switching problem

   • If the stroke-change signal (proximity switches/limit switches and solenoids) is not timed correctly or one side’s pilot signal is weaker, one cylinder can start its stroke correctly but the other ramps in late or at reduced flow.
   • Dirty or weak electric solenoids can also cause delayed or incomplete movement of the main hydraulic spool, which will show up as one slow stroke, especially when oil is hot.

3. Hydraulic pump / compensator / pressure setting

   • If the pump or compensator is marginal and one side sees higher resistance, the system may be “backing off” on that side first.
   • However, if only one cylinder is significantly slower and the other is strong and fast, it’s usually not the main pump alone—more often the control block or cylinder side components.

4. Mechanical side of the material cylinders

   • A dragging or damaged piston on one side can slow that stroke under load.
   • Check for differences in:
     • Rod / piston seal condition
     • Scoring or damage inside the cylinder barrel
     • Any binding in the rod guides

5. Hydraulic oil temperature

   • If the issue gets much worse as the oil warms up, that points strongly to internal leakage (in a cylinder, valve block, or relief valve) rather than simple mis-adjustment.

What I’d do step by step

1. Confirm when it happens

   • Is it:
     • Only when oil is hot?
     • Only under load (concrete) and not with water or empty cycling?
   • That helps separate friction/mechanical from hydraulic control issues.

2. Cycle with water (no line pressure)

   • Run with water in the cylinders and watch:
     • Does one side still move clearly slower with almost no back pressure?
       • If yes → more likely control valve / spool / pump-flow issue.
       • If no (it’s equal with no load) → more likely internal leakage or mechanical drag under pressure on that side.

3. Check the obvious hydraulic stuff

   • Filter condition, any signs of contamination.
   • Solenoid coils for that side: power, magnetism when energized.
   • Listen/feel for a sticking shuttle/spool in the main pumping block when the stroke changes.

4. Swap test (if accessible on your model)

   • If the design allows, sometimes you can swap hoses or pilot lines feeding left/right material cylinders at the control valve:
     • If the slow side “moves” to the other cylinder after the swap → the problem is in the valve/control side.
     • If the same physical cylinder remains slow → the problem is likely in that cylinder or its immediate plumbing.

5. Inspect the slow cylinder

   • Check for:
     • Unequal stroke length or hesitation mid-stroke.
     • Any oil bypass signs: oil levels dropping, odd noises, or cavitation.

Why it’s dangerous for priming

Because on change-over the fast side is outrunning the slurry, you risk:

• Plugging at the front of the line.
• Air pockets and harsh surging when concrete slams into the plug.

Until it’s fixed:

• Prime slower, and keep the boom/line as flat and short as possible.
• Try to avoid backing off/overusing the throttle to “chase” the slow stroke – you’re just masking the imbalance.

Strong recommendation

Hydraulic control blocks and stroke-change circuits on modern line pumps are delicate and easy to mis-adjust. As another experienced operator advised in a similar case, if you start turning screws or changing pressures without factory specs, you can make it much worse.

I’d recommend:

• Get an Everdigm-experienced pump technician or dealer service guy to:
  • Check stroke-change timing.
  • Test actual flows and pressures left vs right.
  • Inspect/clean the control block and solenoids.

If you can, tell me:

• The exact Everdigm model and year.
• Whether the slow side gets worse with hot oil.
• If you notice any unusual noises or pressure spikes when the slow stroke runs.

PumpBot can then walk you through a more model-specific diagnostic sequence. If you want more opinions from other Everdigm owners, you should also post your question with model details and maybe a short video here: