O'Brien: Operation and Maintenance

The 468 and O’Brien turn your jetter into a high-powered cleaning system. Below you can get acquainted with the features and operation of the O'Brien.

After the skid and cutter blade have been attached to the unit, attach the high pressure hose and the placement unit. Next, lower the root cutter into the manhole and position it at the pipe entrance with cutter blade facing in the direction of travel. (If possible, cutting should always be done against the flow to allow debris to be carried back to the working manhole.) Start jetter engine and turn on water pressure momentarily to allow root cutter to enter the line several feet. Then, turn off pressure and position hose guide/guard at pipe entrance. Tie the safety rope to the jet or clamp in place, and mark the hose top of manhole entrance with white waterproof tape.

Begin the cleaning operation by running the engine at low pressure, never to exceed 2000 PSI. Feed the root cutter hose slowly into pipe so cutter can cut obstructions and the blade can rotate freely (a jammed blade could cause jet hose twist and damage). Slack in the hose indicates that the root cutter has encountered an obstruction. When this occurs, immediately pull back on the hose by hand then gradually feed hose forward to allow the root cutter to cut into and through the obstruction. Make sure you have good footing while performing the above action.

If the root cutter does not penetrate the blockage after several minutes, you may have encountered a lateral or collapsed pipe. At this point, other options should be considered such as removing the root cutter and introducing a camera to visually inspect the pipe, as continued operation without penetration can damage the root cutter and/or could cause it to lock-up in the pipe. A blockage has been penetrated when no slack can be felt or seen in the hose. If this occurs, slowly feed the root cutter a few feet further up the pipe to ensure that you are through the blockage. For every 2-3 feet of blockage, pull root cutter back towards the manhole to clear the pipeline of debris (the white tape marking will mark how far cutter is from entry). Do not pull unit all the way into manhole at this time, but reduce water pressure and flow to root cutter to prevent debris from washing into another pipe. If debris does not seem excessive, you may be able to proceed further than 2-3 feet until the line is cleaned.

However, if the amount of debris is excessive on the first run, pull root cutter toward pipe entrance after turning down pressure to allow debris to build up at the bottom of the manhole. Then, turn off water pressure and engine, and remove root cutter from manhole by hand. Clean debris from both the unit and the manhole. Once this is finished, reinsert the hydraulic cutter into the line and repeat this procedure until the pipe is clean.

When the job’s complete, retrieve the root cutter and remove it from the hose. If root cutter will not be used again within a 6 hour period, remove the cutter blade and with the supplied special grease coupler attached to a grease gun, pump light weight grease into the orifice grease fitting (the motor shaft will be turned by the grease as this is done). When grease can be seen at the hose connection the root cutter can be stored. In freezing conditions, be sure to keep root cutter motor unit warm or service with grease immediately. As grease may become thick in extreme cold (and if warming is not possible), service root cutter motor with S.A.E. #10 motor oil. You can do this by first orienting the motor so the shaft is pointing down, then slowly pouring oil into the hose connection at the jet nozzle while turning the motor shaft in a clockwise direction (with provided “T” wrench) as viewed from the hose connection end. When oil is forced out of the orifice grease fitting, oiling is complete.

Note that the 6” cutter assembly and 6” blade are designed for straight or gentle sweeping lines and will not traverse elbows. All cutter units for O’Brien root cutters are attached to the motor shaft by means of a woodruff key and a bolt and nut arrangement. The hub of the cutter must be slid over the key on the shaft which drives the cutter. Align cross hole in hub with hole through shaft and insert bolt through hub and secure with lock washer and nut. This prevents the cutter from pulling off when withdrawing unit.

Two special bypass orifice grease fittings are supplied on the O’Brien. Color coded for easy identification, one style must be selected and screwed into the jet head for proper root cutter operation. The black fitting is for 1” hose units and the plain fitting is for ¾” hose units. The 1” hose fitting (black) is designed for flow capacities of 45-60 GPM, requiring an operating pressure of 1200 PSI (80.5 bars) to 2000 PSI (140 bars).