A sewer camera head is rated waterproof, and the rating depends on a few rubber O-rings at the joint between the head and the rod connector and sometimes at the lens window. They are the cheapest parts in the kit and the ones whose failure costs the most, because water past an O-ring reaches the sensor and the connector and the head is finished. Inspecting them is thirty seconds; replacing them is a few minutes with the right ring and the right grease. This guide covers both.
Quick answer: before any job where the head will be submerged, and after every sewage job, unscrew the head if the design allows, look at each O-ring for cuts, flattening, cracks or grit, clean the groove and the ring, apply a thin film of the lubricant the manual specifies, usually a silicone grease, and reseat the head firmly without overtightening. Replace O-rings that are flattened, cracked or cut, and replace them all yearly as a matter of routine. Never use petroleum grease on rubber it does not suit, and never force a head on over a ring that has slipped out of its groove.
Where the seals are
Most push-camera heads screw or clip onto a connector at the end of the rod, and one or two O-rings in grooves on the connector or inside the head seal the joint. The lens window is sealed into the housing at the factory, usually permanently. Some heads have a further O-ring under a retaining ring at the front. The manual shows which are user-serviceable; the connector rings always are.
Why they fail
Grit under the ring from a dirty reassembly, which cuts the ring or holds the faces apart. Flattening from age and compression, so the ring no longer springs back to fill the gap. Cracking from drying out, especially after exposure to solvents or the wrong grease. Pinching during assembly, when a ring slips out of its groove and is crushed by the thread. Cold, which hardens rubber and widens a marginal gap. Water inside the head is the result.
The thirty-second inspection
With the head off, look at each ring in good light. It should be round in section, uniform in colour, seated in its groove, free of grit and lightly glossy with grease. A ring that is flat on one face, has a visible cut or nick, shows fine cracks when gently stretched, or has gone hard or sticky is replaced. Look at the groove too; a scratch across a groove will leak past a new ring. Check the mating faces for grit and scale. First-time setup puts this at the start of ownership.
Cleaning
Remove the ring with a plastic pick or a fingernail, never a metal tool that scratches the groove. Wipe the ring and the groove with a clean cloth and, if greasy or gritty, mild soapy water, then dry. Rinse the connector threads. Do not use solvents on the rubber.
Lubricant
The manual specifies a lubricant, and it is almost always a silicone grease for the usual nitrile or silicone rings. A thin film, enough to make the ring glossy, helps it seat, keeps it supple and lets the head screw on without twisting the ring. Petroleum greases and oils swell and soften some rubbers and must not be used unless the manual says so. Keep a small tube of the right grease in the case.
Replacing
Buy the maker’s O-ring kit or rings of the same inside diameter and cross-section in the same material; the manual or the old ring measured with a calliper gives the size. Fit the new ring into its groove without stretching it more than needed, grease it, and check it sits evenly all round. Screw the head on by hand, firmly, until it stops; do not use a tool. If the head will not seat or feels gritty, stop and look for a ring out of its groove.
How often
Inspect before any submerged job and after every sewage job. Replace on any sign of damage, and replace the set yearly regardless on a reel in regular use, because flattening is gradual and invisible until it leaks. Rings are cheap; a head is not. When to replace a head is often the consequence of not replacing a ring.
The lens seal
The lens window’s seal is factory-made and not user-serviceable on most heads. If fog appears inside the window after cleaning the outside, the lens seal or a connector ring has failed; try the rings first. A head with a failed lens seal is replaced. Scratched lenses covers the other reason a window ends a head.
Storage
Rings last longer stored clean, greased and out of sun and heat. A head stored dirty with grit under the ring is a head that leaks on the first job of the season. Storage covers the routine.
Heads that do not come off
Some budget reels have the head permanently attached to the rod. Their seals are not serviceable, and the owner’s protection is to keep the joint clean, dry it after each job and not stress it. When such a head leaks, the rod and head are replaced together or the reel is retired. Reels with replaceable heads are the alternative.
Common questions
What grease do I use on sewer camera O-rings?
The lubricant the manual specifies, almost always a silicone grease. Not petroleum grease or oil.
How often should I replace the O-rings on a sewer camera head?
On any sign of damage, and yearly as routine on a reel in regular use.
Why is there fog inside my camera lens?
Water has passed a seal. Check and replace the connector O-rings; if fog persists, the lens seal has failed and the head is replaced.
Related guides
See why head size alone does not determine fit, head size for 2 in pipe, and a compact drain camera reviewed here.