# pump seals 

If it comes to paint leakages on the piston of an Airless spraying machine, action is needed to secure the full performance of the machine and to avoid further damages.

In the video an older Graco Ultra 1000 piston pump can be seen. On the piston are paint remnants.

While doing a test run, water exits on the upper side of the pump (of the piston). Apparently, the Airless machine has an issue with the sealing, further damages are also possible.

In this article, we will discuss the damage, if the seal or packing is impaired. How do you recognize such a damage ? What are the causes ? How can the damage be fixed ?

Paint on the piston of the Airless machine

The piston of an Airless piston pump is powered with an engine and is responsible for the suction and the pressure regulation of the material.

There are several different seals, made of plastic, teflon and leather, around the piston.

These seals are also called packages, package and seal sets.

In the construction drawing below, the Airless piston pump is deconstructed for visualization.

The piston is numbered 23. There are also different seals, for example the numbers 8, 17 and 18.

pump seals piston airless

Packages sets on an Airless piston pump

Which causes are responsible for paint leaks from the piston ?

There are very different reasons for the paint leakage from the piston, starting with attrition and damaged seals, over loose package/seal nuts, to attrition or mechanical damage to the piston or other parts of the pump.

In the following we will describe the most common problems.

Attrition of the seals / packages

Sooner or later through the friction of the piston, the seals were out, which are around the pistons.

These attritions can be countered a little with adding some drops of piston oil regularly to the piston.

Preferably every day before beginning the work.

If attrition of the seals becomes recognizable through paint leakages, you should not wait with replacing the seals.

Some users just keep on working and generate through that unnecessary and expansive further damage between the seals and the piston.

If you keep working, although paints leaks, then paints gets between the seals and piston, hardens and functions as sandpaper between piston and seals.

Exchange of packages on a Graco Mark V

Exchange of packages on a Graco Mark V

Mechanical damage of the seals / packages

Exterior influences on the packages or parts of the pump can of course also result in damages.

For example, if foreign substances, such as stones and screws, are sucked into the pump.

Damage can also occur through improperly assembly of the seals.

Paint leakages on the upper side of the piston pump can also be the result of these kind of damages.

Loose seal nut

The seal nut positions the seals/packages of the piston pump (number 21 on the construction drawing).

If the package nut becomes loose, paint leakages can occur.

That is why the position of the seal nut should be checked primarily.

Further attrition or damages of the pump

Next to the seals, the other parts of the pump, like the piston or the sleeve, can also wear out or be damaged.

These damages can also be responsible for paint leakages on the upper side of the piston pump.

What to do if the packages are damaged ?

Here a short checklist, how you proceed, if paint shows itself on the piston:

  • Check the seal nut
  • Disassemble and check the pump
  • if necessary, exchange the seals
  • if need be, exchange further parts of the piston

Where do I find the right construction drawings ?

On our Airless Discounter website you can find an overview over all Graco and Wagner construction drawings.

We have digitalized these construction drawings of the replacement parts; these are listed in a table.

One click on a replacement part is enough and you get to our online shop and you get the replacement part including price and availability.

If needed the replacement part can be ordered instantly here.

Wagner & Graco replacement part

Wagner & Graco replacement part

You prefer the reparation done by one our technician ?

Call us on 0049 30 22 01 54 36.

We can discuss the damage and clear the next steps.

With our services you will have a great contact which knows Airless machines.

We work fair and transparent (free estimate of costs).

Work shop – Reparation Airless Discounter

Work shop – Reparation Airless Discounter

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Questions or queries ?

For any further questions or if you would like to get your hands on one of these products seen in this article, you can contact us on +49 (0) 30 220 15436, fill out our contact form or email us.

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