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978-368-3325
Compactors & Balers · Hydraulic · H-5

Why Is the Ram Cycling Slower Than It Used To?

A compactor that cycles slower than it used to has either lost flow or lost containment. Worn pump, a cylinder bypassing past the piston seal, a restricted suction strainer, oil too heavy for the season, or a relief partly bypassing. Timing one full cycle narrows it faster than any other single thing you can do.
Get a Cycle Time Checked — 978-368-3325
All Hydraulic Symptoms
Tier 1 to time it. Tier 3 to open the circuit. Serving New England from Clinton, MA.
Step One

Time One Full Cycle

Cycle time is the single most useful number an owner can hand a technician, and it costs nothing but a phone and two minutes.

Start the stopwatch on your phone.

Any stopwatch. Precision to the second is plenty.

Run one complete cycle.

Start of extend through end of retract, with a normal load in the chamber.

Write it down with the date.

Seconds, the date, and roughly how full the container was.

Compare it to when the machine was new.

If nobody recorded that, compare it to a sister unit on the same site, or to the manufacturer's stated cycle time on the data plate or manual.

Note the temperature.

A cold morning and a July afternoon are different tests. Oil viscosity moves with it.

Nobody has the original number. Start collecting it anyway.

Most sites have no record of what the machine did when it was healthy, which is exactly why this symptom gets noticed so late. Time it today and you have a baseline for next year. Time it monthly and you will see a pump going before it strands you.
Narrowing It

Reading the Pattern

Slow is a symptom with five common causes. What comes with the slowness usually points at which.
  • Slow and hot — Oil forced past a worn seal or through a partly open relief turns pressure into heat. Slow plus a reservoir too hot to touch points at internal bypass.
  • Slow and whining — A pump starving for oil screams. That is a suction-side restriction — strainer, low oil, a partly closed valve — and it damages the pump while you listen to it.
  • Slow only when cold — Oil too heavy for the ambient temperature. It improves as the machine warms. Common on units that got a summer-weight oil and then met January.
  • Slow and drifting — Oil crossing the piston inside the cylinder loses motion and holding at the same time. Points at the cylinder.
  • Slow and weak — If packing got looser at the same time the cycle got longer, the machine is losing pressure as well as flow. Relief, pump or cylinder.

The one that is not a fault

A cycle that got longer because the container is packing tighter than it used to is the machine working, not failing — the ram is doing more work per stroke. Compare cycle time at a similar fill level, not a full container against an empty one.
Why It Compounds

A Slow Machine Is an Expensive Machine

Slow rarely stays slow. Every cause on the list above gets worse with running time, and most of them damage something else on the way.

Throughput

Longer cycles mean the chamber accepts less per hour. On a busy dock that shows up as overflow at the compactor door before it shows up in any maintenance log.

Heat

Bypass makes heat, heat thins oil, thin oil bypasses more. It is a loop that accelerates, and heat destroys the seals that were still good.

The pump

A pump running against a restricted suction is being damaged continuously. That is a repair with a deadline measured in hours, not months.
Do This Now

Record a Baseline on the Machines That Are Fine

This is the one piece of preventative work on this page, and it takes a few minutes per machine.
  • Time a full cycle on every compactor on site while it is running well.
  • Write the number, the date and the rough fill level on a label inside the control cabinet door.
  • Repeat quarterly. A drift of a few seconds is nothing; a drift of thirty percent is a fault forming.
  • When you call for service, read the numbers off the label. That conversation starts three steps ahead.

This is also what a PM contract does for you

Cycle time, oil condition, oil temperature and gauge pressure recorded on a schedule are how a failure gets caught while it is still a filter change. It is the difference between a planned visit and a Saturday call.
Before You Call

What We Need to Quote It

You do not need all of this — the make and model plus photos is usually enough to get started. But the more of it you have, the closer the first number is to the final one.
  • Bore — Inside diameter of the barrel. Stamped on many data plates; otherwise we measure it.
  • Stroke — Fully extended length minus fully retracted length.
  • Rod diameter — Across the chrome, measured with calipers if you have them.
  • Mount type — Clevis, cross-tube, trunnion or flange — and the pin diameter.
  • Pin-to-pin retracted — Center of one mounting pin to center of the other, ram fully in.
  • Ports — Size, thread type, and whether they face the same direction or opposite.
  • Machine make and model — Off the data plate. It often tells us the cylinder before you measure anything.
  • Photos — The whole cylinder in place, both mounting ends, and a close shot of the rod.

If you can't get the measurements

Don’t climb on the machine to get them. Send the make, the model and the photos, and we will take the dimensions when the cylinder is out — or bring a replacement with us if we already know that machine.
Safety

Where Your Checking Stops

Tier 1 · Site check

Timing the cycle, reading the gauge, listening, and noting oil level in the sight glass. Nothing opens.

Tier 3 · Service technician

Opening the suction side, pulling the strainer, testing pump output, or adjusting the relief. All of it is inside a pressurized system.

Do not crack a fitting to check for pressure

Stored hydraulic energy is the hazard that makes this Tier 3 no matter how simple the repair looks. Loosening a fitting “to see if there’s still pressure in it” is how people get injection injuries — which do not look serious for the first hour and are a surgical emergency. Pressure gets relieved deliberately and confirmed at the gauge.
Applies To

Compactors and Balers Both

This fault lives in the power unit, so it behaves the same on a stationary compactor and on a vertical baler. One difference is worth naming.

On a baler

Time a full platen cycle the same way. On a vertical baler the number that matters alongside it is bale weight — a machine that got slower and started making lighter bales is losing force as well as flow.
Questions We Get

Slow Cycling, Answered

How much slower is a problem?
There is no universal number, because cycle times vary by machine, load and oil temperature. What matters is the change against that machine’s own history. A cycle that has grown noticeably longer at the same fill level and similar weather is worth a look.
Sometimes, and it is the cheapest thing to try — if the oil is the wrong viscosity for the season, or so degraded it is no longer doing its job. But if the oil is in reasonable condition, new oil will not restore a worn pump or a bypassing cylinder, and the slowness will come straight back.
It can look that way. Reversed phase rotation after electrical work makes a machine that sounds completely normal and does almost nothing. Low supply voltage can slow a motor under load. If the slowness appeared immediately after any electrical work upstream, that is where to look first.
Partly, in New England. Oil that is too heavy for the temperature moves slower until the system warms. The test is whether it comes back to normal once the machine has been running — if it stays slow warm, the cold was not the cause, only the thing that made you notice.
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T&T Weber Hydraulic Inc.
184 Stone St, Unit 5
Clinton, MA 01510

Where we go

Onsite compactor and baler service throughout New England — Massachusetts, Connecticut, Rhode Island, New Hampshire, Vermont and Maine. Cylinder reseal and replacement, domestic replacement cylinders, hydraulic, electrical and controls, and full mechanical repair.