Assembly And Installation Of Conventional Duo-Cone Seals


This instruction gives the procedure for installing Conventional Duo-Cone Seals.

It is most important that correct assembly and installation procedures are followed when Duo-Cone Seals are used. Many of the Duo-Cone Seal failures are the direct result of one or more mistakes made during assembly or installation of the seal components.

(1) Seal(2) Rubber Toric Ring(3) Housing Retaining Lip (4) Housing Ramp (5) Seal Ring Housing

(6) Seal Ring Face (7) Seal Ring Ramp (8) Seal Ring Retaining Lip (9) Installation Tool.


Never permit oil to get on the toric rings or ramps before both seal rings are put together in their final assembled position (Step 10).

------ WARNING! ------

Avoid prolonged skin contact with isopropyl alcohol. Avoid breathing the vapors in enclosed areas without adequate ventilation and do not smoke. Do not use near open flame or welding operations or other heated surfaces exceeding 482° C (900° F).


1. Use isopropyl alcohol with a clean cloth or paper towels to remove any oil film, dust or other foreign matter from toric rubber rings (2) and from ramps (4) and (7) and lips (3) and (8) of both seal rings (1) and housings (5).

2. Put toric ring (2) on seal ring (1), at the bottom of seal ring ramp (7) and against retaining lip (8).


Make sure that toric ring (2) is straight on seal ring (1) and is not twisted. Be careful when you work on the rubber toric ring. Nicks, cuts and scratches can cause leaks.


Do not use Stanisol or any other liquid that leaves an oil film or does not evaporate quickly.

3. Put installation tool (9) onto seal ring (1) with toric ring (2). Lower the rings into a container with isopropyl alcohol until all surfaces of toric ring (2) are wet.

4. With all surfaces of toric ring (2) wet, use installation tool (9) to position seal ring (1) and toric ring (2) squarely against housing (5) as shown. Use sudden and even pressure to pop (push) toric ring (2) under retaining lip (3) of housing (5).

5. Check assembled height (A) in at least four places, 90° apart. The difference in height around the ring must not be more than 1 mm (.04″).

6. If small adjustments are necessary, do not push directly on seal ring (1); use installation tool (9).

7. Toric ring (2) can twist if it is not wet all around during installation or if there are burrs or fins on retaining lip (3) of housing (5).


Misalignment, twists and bulges of the toric ring will cause Duo-Cone Seal failures. If correct installation is not obvious, remove seal from housing and repeat steps 3 thru 6.

IMPORTANT: Toric rings (2) must never slip on the ramps of either seal rings (1) or seal ring housings (5). To prevent slippage, wait a minimum of two minutes to let the isopropyl alcohol evaporate before further assembly. Once correctly in place, the toric ring must roll on the ramps only.

8. Wipe seal faces (6) of seal rings (1) clean. Use a lint free cloth or paper towel. No particles of any kind are permissible on the sealing surfaces. Even a small piece from a paper towel can hold the seal faces apart and cause leakage.

Posted in D6Tagged