COFFEEJACK has been designed so that only limited areas are exposed to coffee grind. There are a series of one way valves to ensure that only clean water passes through the main body of the machine, which significantly reduces the requirement for cleaning.

The video above shows how to clean COFFEEJACK efficiently without the need to disassemble main body components (9 min:42 sec)

This is most likely because there is not enough restriction in the basket to create the back pressure required for a quality espresso extraction. This could be due to the following reasons:

Grind is too coarse (use fine grind only).

Not enough grind in basket (14-16g is recommended).

Tamp compression is too low (25-30 lbs is recommended).

Water temperature is too low (100°C is recommended). This accounts for a temperature drop before reaching the grind between 90-96°C (optimum for espresso).

Channeling has occurred. This is where an unwanted water path has been created through the grind, preventing sufficient back pressure. To prevent this from occurring, pre-soak the grind at low pressure before high pressure is applied (see ‘How to get the Best Results from Coffeejack’).

The video below will take you through each step required to achieve the best results using COFFEEJACK. If you would like to know about a particular step of the process, the video is timestamped into sections.

There are detailed instructions available on our website. It is highly recommended that these are reviewed carefully before using COFFEEJACK.

Please visit: SAFE USE & MAINTENANCE

There is no need to replace the seals unless there is failure and all troubleshooting steps have been completed. If COFFEEJACK is no longer working after these procedures then one of the seals may be damaged and COFFEEJACK will require inspection.

The seal replacement kit only contains the components that could potentially be subject to failure over a long use period. The video below shows a full assembly video for the COFFEEJACK unit which will guide the seal replacement process. All of the components are easily identifiable within the video without the need to measure components.

Seal and valve specifications are not available given that we use custom moulds to create bespoke sized o rings and valves. There are also 5 different shore variants (hard/soft) within the selection. These materials are critical in order for COFFEEJACK to function efficiently.

Replacement Seal Kit available HERE

The basket valve is designed to reduce leakage from used grind in transit. It also enables both a pressurised and unpressurised portafilter to be used during extraction.

Our preference is using COFFEEJACK without the valve in place as this usually achieves the best extraction results. However, it's worth experimenting with and without to make a decision based on your own preference.

Removing and positioning the valve is a quick and simple process.

Use a blunt tool to prevent damage to the valve and lever from the outside edge. To replace, simply push the valve back into position.

The COFFEEJACK portafilter diameter is quite unusual, therefore tampers this size are not readily available online.

We designed our own bespoke Stainless Steel Tamper @ 45.5mm OD

TAMPER LINK: HERE

Once the parcel has been processed, you will receive a tracking number from SFC. This will be delivered to one of the emails used to purchase a COFFEEJACK product.

The tracking number can be used to check delivery status HERE.

This could be due to an air lock in the pressure system (1) or valve detachment as a result of excessive flow rate (2). Both of which offers a simple solution to getting your COFFEEJACK working again.

1. AIR LOCK:

Rotate the lid so that the locking teeth are able to move into the piston cylinder. The lid edges should now be in contact with the edges of the water funnel.

Hold down for 3-5 seconds, then slowly release. For more information, please read 'SAFE USE & MAINTENANCE'. section. If the water level does not decrease, please follow the link provided below.

TOP TIP

Pump with the lid in this orientation so the piston clears the chamber of any air and maximises the stroke length to decrease the number of pumps required for extraction.

If the above steps does not fix the problem, then it is likely that the high pressure valve has detached from the inlet chamber. If this has occurred, there will be no pressure buildup from the piston and water will be ejected back into the glass water chamber with ease.

**Please note, water re-entering the glass chamber is not to be mistaken for the Pressure Regulation Valve (PRV)**

The PRV also recirculates water into the glass water chamber but only when 9 Bar pressure is exceeded. If this happens, slow the pump rate to reduce the pressure and ensure it does not continue actuating. The PRV is a warning that the pressure is too high.

2. VALVE DETATCHMENT:

If the high pressure valve has detached it is due to quick pump cycles. If the flow rate is too high on the return piston stroke, there is chance that it could detach the rubber valve from the inlet chamber. This is why the pump rate is important to ensure that flow rate does not affect the functionality of the one way valve. For more information please read 'SAFE USE & MAINTENANCE'.

This issue can be fixed by removing the screws underneath the shower screen filter to re-mount the valve. Only perform the following steps if the trouble shooting steps above have been completed without improvement.

It is a simple 5 step process which should take no longer than 10-15 minutes:

HOW TO RE-MOUNT THE HIGH PRESSURE VALVE:

(If COFFEEJACK has completely stopped pumping water.

STEP 1

Unlock the piston and leave in the upward position. *This step is important as it unloads the spring, preventing injury during dis-assembly.

STEP 2

Remove the shower screen filter from the bottom of the main body to reveal screws. This can be achieved by levering the side of the filter using a blunt tool. The above shows this step being completed using an easily accessible household tool (handle of a spoon):

STEP 3

Loosen and remove all 5 screws using a cross-head screwdriver (*ensure the driver is the correct size for the screws. It does not have to be too specific, but a driver small enough to prevent damage from rounding the heads).

Before removing the final screw, apply gentle pressure to the centre of the plastic mount in order to control release of the internal spring.

STEP 4

Remove the spring and the piston. You will most likely see that the rubber high pressure valve is no longer seated in the inlet chamber hole. Simply place the valve back in the position as shown below:

STEP 5

Reverse the above steps to resemble COFFEEJACK. The large o ring used to seal the edge of the main basket can be positioned before or after the assembly steps above are complete. This o ring is essential in order to seal COFFEEJACK during use. Ensure not to over-tighten the screws.

You're COFFEEJACK is now ready to use!

HOW TO PREVENT THE VALVE DETATCHING IN FUTURE

Following these steps will eliminate the chance of valve detachment.

STEP 1: PUMP SPEED

Control the upward and downward pumping action with the palm of your hand. This should be a slow and steady process in both directions.

STEP 2: PUMP SPEED

If the Pressure Relief Valve actuates there will be an audible 'squeaking' sound. This is an indicator to reduce the pump speed immediately as 9 Bar has been exceeded.

Please see SAFE USE & MAINTENANCE for more information on how to use COFFEEJACK safely and efficiently.

In the unlikely event that the high pressure valve is damaged, replacement parts are available: HERE

2. VALVE DETATCHMENT:

If the high pressure valve has detached it is due to quick pump cycles. If the flow rate is too high on the return piston stroke, there is chance that it could detach the rubber valve from the inlet chamber. This is why the pump rate is important to ensure that flow rate does not affect the functionality of the one way valve. For more information please read 'SAFE USE & MAINTENANCE'.

This issue can be fixed by removing the screws underneath the shower screen filter to re-mount the valve. Only perform the following steps if the trouble shooting steps above have been completed without improvement.

It is a simple 5 step process which should take no longer than 10-15 minutes:

HOW TO RE-MOUNT THE HIGH PRESSURE VALVE:

(If COFFEEJACK has completely stopped pumping water.

STEP 1

Unlock the piston and leave in the upward position. *This step is important as it unloads the spring, preventing injury during dis-assembly.

STEP 2

Remove the shower screen filter from the bottom of the main body to reveal screws. This can be achieved by levering the side of the filter using a blunt tool. The above shows this step being completed using an easily accessible household tool (handle of a spoon):

STEP 3

Loosen and remove all 5 screws using a cross-head screwdriver (*ensure the driver is the correct size for the screws. It does not have to be too specific, but a driver small enough to prevent damage from rounding the heads).

Before removing the final screw, apply gentle pressure to the centre of the plastic mount in order to control release of the internal spring.

STEP 4

Remove the spring and the piston. You will most likely see that the rubber high pressure valve is no longer seated in the inlet chamber hole. Simply place the valve back in the position as shown below:

STEP 5

Reverse the above steps to resemble COFFEEJACK. The large o ring used to seal the edge of the main basket can be positioned before or after the assembly steps above are complete. This o ring is essential in order to seal COFFEEJACK during use. Ensure not to over-tighten the screws.

You're COFFEEJACK is now ready to use!

HOW TO PREVENT THE VALVE DETATCHING IN FUTURE

Following these steps will eliminate the chance of valve detachment.

STEP 1: PUMP SPEED

Control the upward and downward pumping action with the palm of your hand. This should be a slow and steady process in both directions.

STEP 2: PUMP SPEED

If the Pressure Relief Valve actuates there will be an audible 'squeaking' sound. This is an indicator to reduce the pump speed immediately as 9 Bar has been exceeded.

Please see https://www.coffeejack.co.uk/safeuse for more information on how to use COFFEEJACK safely and efficiently.

In the unlikely event that the high pressure valve is damaged, replacement parts are available: HERE

It is likely that there is too much grind in the basket. Simply remove a small amount of grind to lower the tamp level, allowing the basket to fit smoothly onto the bayonet lock.

If the lid is locked in the downward position it is sealed from atmosphere, meaning residual water is not able to evaporate. Open the lid to either allow the water to evaporate or wipe the inside of the glass. This sealing feature ensures the water chamber remains hygienic between uses.

Use a small microfibre cloth to wipe around the inner wall of the glass chamber to remove droplet marks.

**Do not remove the glass chamber from the main body of COFFEEJACK**

This could be due to the following reasons:

The basket is not correctly fitted/fully twisted to activate the compression seal.

Excessive force is being applied during pumping (20kg+).

There is an obstruction on the top sealing face of the basket edge or the basket o-ring.

The o-rings need replacing (full seal replacement kits available HERE).

Please see 'SAFE USE & MAINTENANCE' for further instructions.

If the pump feels ‘spongy’ it could be that there is air in the system which will slow down the extraction process. COFFEEJACK operates using our micro-hydraulic technology meaning it is important for the system to be absent from air.

How to ensure there is no air in the system:

Rotate the lid so that the locking teeth are able to move into the piston cylinder. The lid edges should now be in contact with the edges of the water funnel.

TOP TIP

Pump with the lid in this orientation so the piston clears the chamber of any air and maximises the stroke length to decrease the number of pumps required for extraction.

Hold down for 3-5 seconds, then slowly release. For more information, please read "SAFE USE & MAINTENANCE' section.

COFFEEJACK has been designed to fit the most popular mug/glass sizes. If a small or fragile mug/glass is used, we recommend using COFFEEJACK with our elevation stand.

Elevation Stand available HERE

This could be due to the following reasons:

Grind is too fine

Too much grind in basket (14g is recommended)

Tamp compression is too high (25-30 lbs is recommended).

COFFEEJACK is able to extract espresso at 9 Bar pressure using the palm of your hand at a reasonable downward force (approx. 12-14kg). Push force required will vary dependent on the restriction in the basket which is determined by grind size, dosage and tamp pressure. Ensure these variables are correct in order for Coffeejack to operate at a comfortable pump force.

For more information on achieving the best results with COFFEEJACK, check out the video at the top of this page.