Northwest Automatic Lubrication, Inc.
Interlube Lube-Block Series Progressive Block
Trouble shooting guide:
Use this Trouble
Shooting Guide when the lubrication system is in pressure relief.
High pressure in the distribution system
can be caused by a blockage at the end of a distribution line or by contamination within the distribution block. Follow the procedure listed to determine the location and type of blockage.
A series progressive distribution block
relies on the lubricant moving spool valves in the block sections in a specific series to move the lubricant out of a block
segment in to the distribution line to the bearing. If a blockage occurs at the
end of a distribution line or in a block segment the next spool in the series cannot move and hydraulic back pressure builds
eventually going over the pressure relief valve.
The system pressure relief should
be between 4,500 and 5,000 psi. If the pump is equipped with a gauge the pressure
relief setting can be determined by checking the gauge, if not install a pressure gauge in-line to make sure the pressure
relief is set at the correct level.
To locate the blockage loosen the inlet
fitting at the distribution block farthest from the primary distribution block. Always start at the block farthest from the primary block. The primary block is the block that is connected to the pump and has lines connected to the
secondary blocks. The primary block may in some cases feed both secondary blocks and bearings, but will always be connected
to the pump.
when the fitting is loosened and there is a high pressure release of grease, the blockage is in that block assembly. If there is not high pressure at the block inlet there is not a problem in that block
assembly. Move to the next block assembly closer to the primary block and perform
the same test.
There are two basic types of blockages
in series progressive systems.
Blockages at the end of a distribution line:
These types of blockages are usually caused
by a broken line being capped after it has been broken in some manner. This is
done because of the thought that the entire reservoir of grease may be pumped out of the broken line. With a series progressive type system a broken line will only lose the amount of grease designated to that
line, all of the other points will get there designated amount of grease. If
a broken line will cause an environmental hazard you can tie strap a bag over the end of the broken line to collect the grease
until the line can be repaired. Another rare cause of a blockage can be a crushed
steel line or a rotated bushing, blocking the grease access hole.
To locate the blockage use the following
you loosened the inlet line there was a high pressure rush of grease out of the fitting indicating high pressure in the block
assembly. Re-tighten the inlet line and press the extra lube button to start
the pump and bring the system back up to pressure relief. Then loosen each of
the lines on the side of the block starting with the top left side. If you loosen
all of the lines and no pressure is found then the blockage is inside of the block assembly, go to (Blockages inside of a
Block Assembly). If you loosen a line on the outlet side and you have presure at
that line, the blockage is at the bearing end of the line. Consult a block
schematic or trace the line to locate the bearing end of the line and find out what is causing the blockage. After correcting the line blockage make sure that all lines are tight at the block, then press the extra
lube button at the pump and test the system to make sure that there are no other blockages.
Blockages inside of Series Progressive Block Assembly:
Blockages inside of Series Progressive
Blocks are mainly caused by contamination in the grease. Particles as small as
dust that are blown into an open reservoir lid can cause an enormous amount of trouble.
Grease Lubrication Systems should be treated with the same care as a hydraulic system.
In-line filters are available and can be purchased from your system supplier if contamination is a great concern.
To locate a blockage inside a block assembly use
the following procedure. When you loosened the inlet line at the block assembly
there was a high pressure rush of grease out of the fitting indicating high pressure in the block assembly. Re-tighten the inlet line and press the extra lube button to start the pump and bring the system back up
to pressure relief. Then loosen each of the lines on the side of the block starting
with the top left side. If there is no pressure at any of the lines you have
determined that the blockage is in the block assembly. After marking the lines
to ensure that they are re-connected to the same outlets, remove the distribution lines and clean the block assembly. Remove the allen caps and plates, (a small magnet can be helpful to remove the plates
under the allen caps), on both sides of the block to give access to the spool valves.
Using the back end of a small drill, press the spool of each block segment back and forth until you locate the spool
that is stuck. By pressing back and forth you may be able to free the spool and
dislodge the piece of contamination. Even though you may be successful at freeing
the spool you will want to order and replace the block segment that had the seized spool.
I t has been our experience that once a spool has seized it will do so again from the scoring of the spool. If you remove the spools from the block segment be sure to keep them in order and replace them into the
same block segment.
After you have repaired the block assembly,
install a grease zerk into the inlet of the block assembly and use a hand grease gun to test the block. Then re-install on the machine making sure to re-connect the distribution lines to their correct ports. Press the extra lube cycle button on the pump and run it through several cycles to
check the distribution system.