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978-368-3325
Compactors & Balers · Hydraulic · H-13

There's Oil Under the Machine. How Do I Find Where It's From?

A compactor can leak from seven places: the rod gland, a hose or fitting, the pump shaft seal, the valve body, a reservoir weld, a barrel weld, or the drain plug. Finding which one takes a sheet of cardboard and one overnight, and it changes the repair completely — so it is worth doing before you call.
Report a Leak — 978-368-3325
All Hydraulic Symptoms
Tier 1 to find it. Tier 3 to fix it. Contain it first if it is reaching a drain.
Before Anything Else

Contain It First

Finding the source can wait an hour. Stopping it from spreading cannot, particularly on a slab that drains anywhere.

Look at where the slab drains.

A compactor pad that runs to a storm inlet, a trench drain or open ground is a different problem than one draining to a contained sump.

Get absorbent down.

Pads, socks or granular absorbent between the leak and the drain. Most sites that handle waste already have a spill kit.

Stop the spread, not the leak.

Do not start opening fittings or chasing it up onto the machine. Containment is a Tier 1 job; the repair is not.

Tell whoever owns the site's environmental reporting.

That call is theirs to make, not yours and not ours — but they cannot make it if nobody tells them.

Photograph it.

Extent of the spill, where it is heading, and the machine. Useful for the repair and for the paperwork if there is any.

Step Two

Map the Drip With a Sheet of Cardboard

This is the whole diagnostic, and it works while you are not there.

Clean the slab under the unit.

You are looking for new oil, not the last five years of it.

Lay flat cardboard under the whole footprint.

Corrugated shipping cardboard is ideal. Cover the full area, not just where you saw the puddle.

Mark the cardboard with the machine's layout.

Rough sketch, or just write “pump end” and “ram end” on it so you can orient it later.

Leave it overnight, running normally.

A leak that only shows under pressure needs the machine to cycle.

Read the map in the morning.

Where the drips landed tells you which end and which side. Photograph the cardboard before you move it.

Then do the rod test

Wipe the cylinder rod clean, run one full cycle, and look again. If a wet film returns on the rod after a single stroke, the rod gland seal is the source and you can stop looking. If the rod stays dry, the leak is one of the other six.
Reading the Map

Seven Places a Compactor Leaks

Where the oil lands narrows it, and each source is a different repair at a different price.
  • Rod gland seal — Drips track down the rod and fall near the ram end. Confirmed by the wipe-and-cycle test. Reseal or replacement cylinder.
  • Hose or fitting — Drips along a hose run, often away from both ends, and frequently worse under pressure. Usually the cheapest repair on this list.
  • Pump shaft seal — Oil at the pump end, typically at the coupling between motor and pump. Points at the pump, and sometimes at misalignment that caused it.
  • Valve body — Wet around the valve stack or the solenoid coils. Can be a fitting into the valve rather than the valve itself — worth separating before condemning it.
  • Reservoir weld — A wet seam or a steady track down the outside of the tank. Welded repair, and a reason to look at what cracked it.
  • Barrel weld — Oil from the cylinder body rather than the rod. Usually terminal for that cylinder.
  • Drain plug — The one genuinely good outcome. A loose or failed plug or gasket, and an inexpensive fix.

Two leaks at once is common

A machine old enough to have one leak often has two. If the cardboard shows drips in two separate areas, say so when you call — it changes what we bring and it avoids a second visit for the leak we did not know about.
Beyond the Machine

The Environmental Side Is the Urgent Part

The mechanical repair can usually wait a few days. The release often cannot.

Slabs that drain

A compactor pad running to a storm inlet puts hydraulic oil into the storm system. Whether that becomes a reportable release is a question for whoever handles the site’s environmental compliance — but it needs to reach them.

Self-contained units

These handle liquid waste by design. An oil track mixing with leachate at a retail or residential site is the version that gets photographed and escalated fastest.

Containment pays for itself

A drip tray or a bermed pad under a known-leaky machine buys time to schedule the repair properly instead of taking an emergency call on a Sunday.

We are not your environmental consultant

We fix the leak and we will tell you plainly what is leaking and how bad it is. Whether a release is reportable, and to whom, is a determination for your environmental contact or the property owner. We would rather say that clearly than have anyone rely on a hydraulics company for it.
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

Containment, laying cardboard, wiping the rod, running a normal cycle, looking and photographing.

Tier 3 · Service technician

Tightening, replacing or opening any fitting, hose, valve or cylinder. A hose that looks like it just needs a turn is a pressurized line.

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

Oil on a retail back-room floor is a slip hazard and a housekeeping finding before it is a mechanical one — and it is usually photographed by someone other than maintenance. Contain it first, same as outdoors, but for a different reason.
Questions We Get

Leaks, Answered

How much oil is a problem?
Any oil reaching soil, a storm drain or a waterway is a problem regardless of volume, and that is a compliance question rather than a mechanical one. Mechanically, a loss large enough to drop the sight glass is also a risk to the pump — running a pump down to the suction inlet damages it quickly.
Topping off keeps the machine alive and it is the right short-term move to protect the pump. It is not a repair, and it means the oil is going somewhere — usually onto the slab. Add it to the list of things to fix, do not let it become the fix.
It is common and it is diagnostic. Leaks that only appear under pressure point at hoses, fittings, the valve body or a seal that only fails when loaded. Leaks that drip with the machine off point more toward the reservoir, the drain plug, or a return-side connection.
It helps to clean the area first, but be careful what you aim at. High pressure water driven past a tired wiper or into an electrical enclosure makes two new problems while solving none. Wipe it down rather than blast it, and keep water away from the control cabinet.
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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.