[This article was originally published in 2020 by Trucks, Parts, Service. It has been updated to include more timely information.]
One of the most commonly sold products in the aftermarket also is one of the easiest to make.
Hydraulic hoses, vital to the operation of medium- and heavy-duty trucks and trailers, are predominately sold in today’s aftermarket as pre-assembled finished products. While the sales volume and corresponding revenue that can be accrued in that manner is substantial, selling packaged hoses alone won’t address every customer’s needs every time.
In some cases, truck owners require custom hoses and, in those situations, distributors who have the ability to produce hydraulic hoses quickly can provide valuable customer solutions while also capturing additional revenue at higher margins.
With the purchase of a few machines and some raw materials, parts distributors easily can integrate hydraulic hose assembly into their service capabilities.
Before any production on a new hose begins, supplies and tools must be acquired. The biggest investment comes in the acquisition of a crimping machine and crimping die and collar. Distributors intending to make hoses with lengths and dimensions similar to what they already have in stock likely will not require the most advanced machine available, though if hose production is being viewed as a way to enter other markets or industries (such as construction, agriculture, etc.), a more advanced machine may be required.
Other materials required are mostly hand tools and raw materials. Longer than required hoses are the first item that should be procured — extra length will be removed during production — along with hose fittings and lubricants, hose saws, chalk or paint pens, an insertion depth block, lubricant and, of course, safety equipment.
Building a hydraulic hose
Once all equipment and materials are pulled together, the hose should be measured and cut to the necessary length with the hose saw. With critical hose lengths, be sure to account for cut-off factor when determining a final hose length, says Kyri McDonough, marketing services manager, Hose Products Division, Parker Hannifin.
“The hose cut length for a hose assembly is calculated by subtracting the cut-off factor (distance from the bottom of the ferrule or collar to the end of the fitting or an internal sealing surface),” McDonough says.
Hoses also should be checked to ensure they have a clean, flat edge after cutting as jagged, uneven hose ends can increase the risk of contamination.
After a hose is measured, it’s time to determine the proper fitting. Fittings should come from the same manufacturer of the hose, and future use case and hose diameters should be considered to determine fitting needs. Hose and fitting manufacturers also advise considering pressure levels, attachment methods, corrosion resistance and other needs when choosing a fitting.
Using the hose insertion depth block, mark the hose using the chalk or paint pen to determine where the fitting will sit within the hose. Lubricate the hose (unless it’s a spiral hose), then insert the fitting into the hose, ensuring it reaches the marked position.
From there the hose and fitting can be set into the crimping machine. Manufacturers note positioning a hose within the machine and setting crimping diameter are among of the most important aspects of the hose assembly — failing to do both properly will lead to faulty or damaged hoses. Some manufacturers also provide educational materials for customers to confirm proper crimp diameter and crimper die for the hose and fittings being used.
“The short answer is the hose end should be positioned properly in relation to the style of crimp you are using,” says Blake Mogil, inside sales specialist, DiscountHydraulicHose.com. “Always refer to the crimper manufacturers instruction for best results.”
If not already on, now is the time to put on safety equipment and prepare to crimp the hose. Crimping is the most important step in hose assembly yet it’s also quite simple, as the crimping machine does the work. Hose companies note to not touch the hose until the machine has completed its crimp. McDonough says some crimping machines will stop automatically if a die is misplaced during preparation, which enables a user to reset the equipment properly before proceeding to avoid damaging or ruining the hose. Both ends of the hose should be crimped using the same process.
Once the machine is powered down the technician can check the crimp. The chalk or paint mark made on the hose earlier should still be visible where the hose and fitting meet. Failed crimps should be discarded, Mogil says.
“You should not re-crimp an improperly crimped fitting. People do, but you should not. It could have a disastrous outcome,” he says.
Adds McDonough, “Users should never re-crimp a hose if done incorrectly due to the implications it might have on the quality of the crimp.”
Now that the hose is assembled it should be cleaned before being used. A common cleaning method is using compressed air with projectile pellets to cleanse the hose interior. Mogil says this process really scrubs the inside of the hose “to ensure maximum debris is removed.”
Many manufacturers sell cleaning kits featuring the tools necessary to complete such a task, such as Parker Hannifin’s Ultra Clean system that McDonough says “reduces downtime, extends filter life and reduces the risk of hose failure and premature wear due to contamination by removing rubber dust and metal particles from the cutting process on hydraulic hose and metal flash from the hose crimping process.”
Hose brushes also can be used, though they lack the capability of the compressed air method.
Finally, any completed hose should be capped and stored to remain clean for future use. Heat shrink caps — slipped around the end of a hose then quickly heated to become airtight — are the preferred capping method for most manufacturers. As for storage, Mogil says completed hoses should be coiled neatly and shelved or hung in a cool, dry place.