Identifying issues early helps prevent minor wear becoming costly downtime. Below are the most common rubberware issues Skellerup Dairy Technical Specialists see in sheds and why timely action matters.
1. Overdue liner changes
Milking liners have a defined service life. Over time they lose elasticity, absorb milk fats and chemicals, and develop fine cracks.
What to look for: Flex cracks or splits, distorted or swollen mouthpieces, rough internal surfaces, increased cup slip, longer milking times, or signs of teat damage.
Why it matters: Worn liners can harbour bacteria, reduce effective teat massage and compromise milk out. This increases the risk of mastitis and elevated somatic cell counts. Replacing liners every 2,500 milkings helps maintain an airtight seal, correct pulsation and consistent milking performance.
Change liners every 2,500 milkings. Plan your replacement schedule with our Liner Change Calculator.
2. Ill-fitting or incorrectly installed liners
Even new liners can underperform if they’re not installed correctly or matched to the herd and claw size.
What to look for: Twisted liner barrels, liners slipping off claws, cracked tailpieces, signs of overstretching during installation, or incomplete milk out.
Why it matters: Correct mouthpiece size is critical for achieving an airtight seal around the teat and consistent milk out. Incompatible or poorly seated tailpieces strain the rubber, leading to premature failure. Sharp edges, burrs or protein buildup on claws can further damage tailpieces. Correct alignment and compatible sizing protect liner integrity and vacuum stability.
3. Mouthpiece distortion from jetters
Leaving clusters on buttonstyle jetters after washing is a common cause of liner mouthpiece distortion.
What to look for: Misshape mouthpieces or clusters left sitting on jetter cups.
Why it matters: Distorted mouthpieces prevent a proper seal, increasing air admission and cup slip. Removing clusters promptly allows airflow for drying and helps maintain liner shape.
4. Cup slip and incomplete milk out
Cup slip is usually a symptom of an underlying rubberware or setup issue.
What to look for: Frequent liner slips, uneven milk out, poor cluster alignment, or poorly fitted tubing.
Why it matters: Worn liners, incorrect liner type or poorly fitted components compromise vacuum stability, reducing milk out and milking efficiency.
5. Perished or deteriorating milk tube
Milk tubing is often overlooked but plays a critical role in milk flow and hygiene.
What to look for: External cracking, black residue inside tubing, or uneven wear.
Why it matters: Deteriorating tubing can harbour bacteria and restrict milk flow. Regular inspection and at least seasonal replacement supports milk quality and plant performance.
Support for your farm
Confident your rubberware is performing as it should? Skellerup offers a free on-farm Rubberware Review with certified NZMPTA specialists through your local Farm Source store.
Book your free Rubberware Review today
Article supplied by Skellerup
