Hunter G835 - Riser Seal Replacement - G80 Risers

RiSeR SeAl RePlACeMenT
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g80 RiSeRS
The G80 riser seal-block assembly and the compressed retraction spring are retained on the riser with the shroud/
logo-cap assembly. It is necessary to remove this assembly in order to service the G80’s riser seal components. To
remove the shroud/logo-cap assembly, it is necessary to fully compress the riser spring by grabbing the riser seal-
block assembly, pressing downward and then holding riser rmly to prevent the spring from moving upwards (g 47).
Caution! The riser assembly is under spring tension. Eye protection should be worn and safe-handling
procedures followed when servicing this product.
Press the riser seal-block assembly down with one hand and hold rmly. Locate the stainless-steel retaining screw
on top of the shroud/logo-cap assembly (g 48). Use a Phillips screwdriver to engage the screw and turn counter-
clockwise to remove. Prior to removal of the shroud, take note that the large nozzle arrow on top of the shroud’s
rubberized logo cap is orientated directly over the larger, long-range nozzle. This will help with the shroud installation
process later.
While rmly holding the compressed spring and seal-block assembly downward, grab and lift the shroud off the
nozzle housing then set it aside (g 49). Slowly lift to release the spring compression. Note the orientation of the
seal-block assembly for installation later (g 50). Next, remove the seal-block assembly and retraction spring.
The riser seal on G80 risers include two primary components - the seal block assembly and the face-seal. The seal
block assembly sits on top of the retraction spring and has two sealing surfaces. First, the seal block has an o-ring
around the outside. If the o-ring is damaged, deteriorated or missing, the riser will leak water while the sprinkler
is operating. The second sealing surface on the seal-block assembly is on the underside. The angled surface on
the underside of the seal-block assembly is the interface for the face-seal. If this angled interface surface is cut or
otherwise damaged, the riser can leak water during sprinkler operation.
The face-seal is the second primary component to the G80’s riser seal design. The face-seal is the white plastic
angled ring that is position at the base of the stainless-steel portion of the G80’s riser. If the face-seal is damaged,
deteriorated or missing, the riser will leak during sprinkler operation.
If the riser is leaking during sprinkler operation, the o-ring, the interface and the face-seal must be inspected in
order to determine the cause of the leakage. If the o-ring is damaged, it can easily be replaced by removing the
damaged o-ring from the seal-block and replacing it with a new one. Use care to ensure that the o-ring is not cut or
twisted during the installation process. If the interface is damaged, the entire seal-block must be replaced. Also, if the
interface is damaged it is highly likely that the face-seal is damaged as well and needs replacement.
To replace the face-seal, slide it upwards and off the riser assembly. Replacement face-seals must t very snug to
the stainless-steel on the riser. As a result, there may be considerable resistance when attempting to install the new
face-seal. To make installation easier, the face-seal’s diameter can be expanded by placing it in the sun for several
minutes. Or, if the repair is being done in the shop, placing the face-seal in warm water for several minutes will cause
expansion as well.
Slide the new face-seal down and onto the riser. Make sure that it is pressed all the way until it is seated rmly against
the ledge at the base of the stainless-steel portion of the riser. Install the retraction spring and seal-block assembly
onto the G80 riser. Press down on the seal-block to compress the retraction spring and hold rmly in this position.
To install the nozzle housing’s shroud/logo-cap assembly, position it over the nozzle housing. The single opening for
the Primary long-range nozzle in the shroud must be positioned directly over the long-range (largest) nozzle. Press
into position and conrm all three nozzle openings are lined up with the nozzles inside. Install the stainless steel screw
into the rubberized logo cap by turning it clockwise until hand tight.
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