How do I rebuild the bladders?

Moisture working its way into the bladders is what can create the majority of issues that lead to bladder replacement.

Minipack highly recommends to use an angled tray for liquids to prevent these issues from occurring and decrease oil contamination. Order an angled tray for liquids today to prevent bladder issues.

Other possible issues:
The sealing bar on the machine has one of the following symptoms:

  • Loss of continuity
  • Loss of bag vacuum
  • Inconsistent sloppy seal
  • Raises unevenly
  • Lacks contact with red lid cushion

Important: The following instructions to be performed by Certified Technicians only!

Estimated bladder removal and bladder rebuild time: 1.5 hrs per sealing bar
(We recommend rebuilding all bladders per sealing bar at the same time)


Tools needed:

  • Phillips screwdriver
  • Pliers
  • 2.5mm allen wrench
  • 7mm socket
  • Heat gun
  • Loctite
  • Acetone
  • Clean cloth


Step 1: Remove bladder

  1. Disconnect vacuum hose and electrical transformer from bottom of the bladder and remove the locking nut inside the chamber that holds the bladder in place.


Step 2: Disassemble bladder

  1. Use pliers or vice grip to tightly grip steel post against the white bushing to keep spring inside from releasing too fast.
    Caution: Spring is in tension!

  2. With a Phillips screwdriver carefully remove all (8) screws that hold the upper and lower body of the bladder together.

  3. Slowly separate the two bodies from each other, and remove spring between them.

  4. Remove old bladder gasket. Use a clean cloth and Acetone to clean all parts of the bladder.


STEP 3: Reassemble bladder

  1. Replace gasket

    Align the holes of new gasket with notches on lower bladder body.


  2. Replacing the inner wire

    1. Loosen thread locker by using heat gun to heat bottom section of metal post on center disk.

    2. Grip the metal post on the bottom side of center disk with pliers. Use 2.5mm allen wrench to loosen and remove screw on back side of disk. Remove old inner wire and replace with new inner wire.

    3. Install metal post on disk by applying some Loctite on half of the screw (section closest to screw head). Tighten screw as much as possible.

    4. Use the 7mm socket to loosen and remove screw on upper bladder body. This will also remove the locking nuts and washer on top of upper bladder body. Replace wire and re-apply locking nuts.

    Apply washers/nuts in this order from bladders piece up: locking washer, locking nut, wire, locking washer, locking nut as in photo 3b-4 below.


  3. Assemble bladder body

    1. Set 4 screws into lower bladder piece in "x" formation ready to be inserted into upper bladder body (photo).

    2. Set coil on metal post. Insert metal post into upper bladder body, and white bushing on top over metal post.

    3. Push center disk upwards and tightly clamp metal post against white bushing with pliers to keep spring tight.

    4. Connect upper and lower bladder bodies together by carefully aligning marker strips located on their sides, and quickly screwing in the 4 screws. Insert other 4 screws and tighten.

    Apply 10 lbs of pressure on locking nuts when installing bladder back into chamber of machine.



Bladder Shaft (removal & installation)

1. Remove bladder assembly from chamber

2. Carefully split the top portion of the from the bottom part. *note: refer to document "how do I rebuild the bladders?" 

3. Hold the bladder shaft with a locking plier

4. Heat the shaft witha heat gun (not a torch) on high for 30 seconds.

5. Carefully loosen the screw with a 2.5mm/hex wrench

6. Install new shaft & inner wire onto disk. Note: use a drop of lock-tight glue on tip of screw before inserting into shaft.

IMG 2245


Minipack does not assume any responsibility or liability for the advice given and shall not be liable for any direct, indirect, special, incidental or consequential damages in connection with the use of this information.