JBL CristalProfi e402/e702/e902 Pump Head Gasket

JBL CristalProfi e402/e702/e902 Pump Head Gasket is the rubber seal between the pump head and the canister on JBL CristalProfi e400, e700 and e900 external filters.

Key Features

• The part that keeps the canister dry: One rubber ring is all that stands between a pressurised canister and the floor of your cabinet. When it hardens or takes a set it weeps, the filter loses its prime, and the pump starts pulling air instead of water.
• Covers the whole e400 to e900 range: JBL list it for the e400, e700 and e900 filters in both generations, which is what their part name e4/7/900/1,2 is describing. The e1500 and e1900 take a different and larger seal.
• Cheaper than the problem it prevents: A seal costs a fraction of what the filter did. A filter out of service is a tank losing its biological filtration, and a slow leak inside a closed cabinet is usually only found once the chipboard has swollen.
• A service item, not a repair: Gaskets are meant to be replaced periodically. Clamping the clips harder onto a tired seal distorts the housing and makes the next seal fit worse.

Changing It

• Unplug the filter and close the taps on the hose block before anything comes apart.
• Lift the old ring out and clean the groove it sat in. A strand of filter wool or one grain of gravel trapped under the seal is the commonest reason a filter still leaks after a service.
• Seat the new ring evenly all the way round without stretching it to fit. Silicone grease helps it bed down; petroleum jelly swells rubber, so keep it away.
• Close the clips a little at a time on alternate sides rather than forcing one fully down first.
• Refill, restart it, and lay a dry tissue along the seam. Watch it for ten minutes before you shut the cabinet door on it.

Good To Know

• Check the model before ordering. This is the e400, e700 and e900 seal. The e1500 and e1900 filters use the larger gasket, which we list separately.
• Change it at every second or third full strip down, or sooner if it looks shiny, flattened along one side, or cracked anywhere.
• Clean it with warm water and a cloth only. Detergents and solvents attack the rubber and shorten its life.
• Keep a spare stored flat and out of sunlight. Rubber perishes in heat and UV, which is exactly what a sunny shelf provides.