Assembling a hose end looks tricky at first, but it’s actually very simple. It’s important to make sure you follow the proper procedures to ensure correct assembly, reliability, and performance. Remember, hoses fittings aren’t just for looks or for delivering fluids, they are safety items designed to ensure that the fluids they are carrying get to where they need to go without leaking. Failure properly assemble these parts can lead to poor performance or leaking flammable fluids, and we all know that’s not good!
Step 1: Cut the hose to desired length.
Measure twice and make sure the hose is the length necessary to go from Point A to Point B. If necessary you can try cutting it a bit longer than you actually need to, then shortening it up a bit until the length is just right for your application. It’s important to ensure you get a clean perpendicular cut on the hose, as deviations can cause the hose to not seal properly inside the hose end, leading to leaks.
Note: Cutting the hose requires special tools. We don’t recommend using metal cut-off wheels or abrasive cutting tools as these can cause a large amount of rubber dust to build up in the hose which must be cleaned prior to continuing the assembly process. Failure to clean can result in the dust entering your parts, causing damage. We recommend using the FLF Hose Cutting Shears.
Step 2: Insert hose into the socket/collar
Place the socket in a vise (preferably with our Vice Jaw Insert) and insert the hose until the end of it is close to the bottom of the threads. There should be an approximately 1/8″ (2-3mm) between the threads and the end of the hose. Getting this right is important because if it’s not all the way in, the hose may not seal against the hose end body. When inserting the hose, be sure to keep the braiding intact, particularly if you’re using nylon braided hose. If it gets too frayed, it will increase the outer diameter of the hose and make it difficult to insert into the socket.
Step 3: Lubricate the hose end body
Apply a small amount of oil to a rag and use the rag to apply the oil to the hose end body. Only a thin layer is necessary. Do not use anti-seize or grease. Be sure to cover the threads, nipple, and if desired, lubricate the threads on the socket and inside the hose. Only a small amount of oil is necessary to help the parts slide. Don’t go nuts.
Step 4: Assemble!
It is highly recommended to use the FLF Vice Jaw Insert and AN Double-Ended Wrenches with a vise that is securely mounted to a sturdy workbench. Push the hose end body into the hose through the socket and hand-start the threads to ensure proper engagement. Turn until you are unable to rotate the hose end body any further by hand.
If you feel ANY kind of significant resistance or binding while starting the threads, stop and inspect for obstructions immediately. The threads are very fine and made of aluminum, and any binding means there is a flaw that can strip the threads, ruining the fitting.
Place the hose end into the vice jaw with the other part exposed, and rotate with the appropriate size wrench until seated. You should be able to get the hose end body to within about 1/16″ (1-2mm) of the socket. This is best to ensure a proper seal and to make sure it looks good.
Step 5: Clean and Test
Clean the hose and hose end with a solvent to remove any excess oil or residue, then immediately pressure test the completed assembly. If you encounter any leaks, determine the reason why and take steps from there to resolve the leaks. If you do not have access to a pressure tester, then when the hose assembly is installed in the vehicle then ALWAYS make sure you observe for any leaks or issues before putting the vehicle into service.
