Tube Bite Hose Couplings
Tube Bite Hose Couplings (End Style 850)
RYCO Hose Couplings Series with Tube Bite End Style 850 (T2850, T4850 and 6850 Series) provide a quick and convenient method of connecting Imperial Outside Diameter seamless steel hydraulic tubing, without the need to flare the tubing. They allow quick and economical repairs to assemblies made of combined hose and Imperial-sized tubing. Often in these assemblies, the tubing is bent to a special shape or includes special mounting brackets, and is difficult or expensive to replace.
- Ensure that the wall thickness of the tubing is of the approved gauge. See S134 J-Lok & Tubing Selection Table page 511.
- Cut the tube to required length. Ensure that the tube is cut squarely. A tube cutter is preferred, however a hacksaw or abrasive drop saw may be used providing the cut is square and clean.
- Deburr inner and outer edges of tube.
Remove dirt, grit and cutting debris from the inside and outside of the tube.
Remove the Nut and Compression Olive from the T2850, T4850 or 6850 coupling.
Lubricate the threads of the Nut and the Male Thread of the T2850, T4850 or 6850 coupling with assembly oil or hydraulic oil.
Lubricate internal and external surfaces of the Compression Olive with assembly oil or hydraulic oil.
Slide the Nut onto the tube, so that the threads of the Nut face towards the end of the tube to be assembled to the coupling, then slide the Compression Olive onto the tube.
The end with the raised collar must be adjacent to the Nut, and the end with the long parallel section must face towards the end of the tube to be assembled to the coupling.
Insert the tube end into the Male Threaded end of the T2850, T4850 or 6850 coupling, until it bottoms against the shoulder inside the Male Threaded end.
Slide the Nut and Compression Olive along the tube until the Compression Olive seats inside the coupling body, and thread the Nut onto the Male Threaded end of the coupling.
Tighten Nut until the Compression Olive just grips the tube. The initial gripping of the tube is complete when the tube can no longer be rotated by hand.
- Place a mark on the Nut, and an adjacent mark on the Hex of the T2850, T4850 or 6850 coupling insert.
- Holding the hex of the T2850, T4850 or 6850 coupling insert stationary with one spanner, with another spanner tighten the Nut down by one full turn, to compress the Olive onto the tube1.
- Use the marks from Step 5 as a reference. Ensure that the tube end is firmly butted against the shoulder inside the coupling, and that the tube does not rotate2.
- Disassemble the Nut from the Coupling.
- Inspect the front edge of the Compression Olive. For correct assembly, the cutting edge of the Compression Olive must have formed a shoulder on the tube at least 50% as high as the cutting edge, all the way around the tube3.
- Attach the T2850, T4850 or 6850 coupling onto the hose, without the tube, Nut and Compression Olive connected to it.
- Refer to the appropriate Assembly Instructions for the Hose Series and Coupling Series being assembled.
- Do not assemble the coupling onto the hose until Steps One to Seven are completed.
- Re-assemble the tube, Nut and Compression Olive onto the T2850, T4850 or 6850 end of the hose assembly.
- Nut will turn easily until an increase in force is required. At this point, orient the bent tube assembly pointing to the correct direction if required.
- Holding the Hex of the T285, T485 or 685 coupling insert with one spanner, with another spanner tighten the Nut down a further 1/6 of a turn as a minimum, but no more than 1/3 of a turn, to complete tightening operation.
- This is a general rule, and may vary slightly with different tubing materials.
- In some instances (especially when using soft or thin-walled tube), to prevent excessive tube collapse, it may be necessary to support the inside of the tube with a mandrel prior to setting the Compression Olive.
- Note that the maximum allowable radial collapse of the inner tube diameter is 0,25 mm (.010”).