Service Manual
13/20
1.5 Issue
Ref. NR-00008-ENG
http://www.gamapur.com
Reassemble the check valve and side seal assembly.
In the model with a metal seal, you must fit the spring and the check valve into the retainer. To
facilitate assembly, use a little grease to fit the o-ring in the metal seal cap; make sure that it is
not damaged and replace it if necessary. Press the metal seal cap into the retainer until the o-
ring is fitted in its groove.
Hand-tighten the metal seal and retainer into the side block. If you use a spanner, do not over
tighten the retainer more than 1/4 of a turn.
PRECAUTION:
Do not tighten the check valve retainer excessively. Tightening more
than 1/4 of a turn can damage the plastic/metal check valve and cause leaks.
Check the wear on the metal seal, by measuring the distance that it stands out from the cap
housing. If the seal is worn, knocked or scratched, it can cause leaks. Replace the seal if it
stands out less than 1.65 mm / 1/16 inch.
To check whether the metal check valve is damaged as a result of excessive tightening, make
sure the separation between the support face of the side block and the bottom of the cap
housing, once fitted, is 0.46 mm / 1/64 inch. If the separation is smaller, the check valve must
be replaced.
Assemble the screen screw and screw it into the side block.
Fix the Polyol side block onto to the gun block with the corresponding bolts. Tighten alternately
to avoid possible leaks.
Perform the same steps with the side block on the Isocyanate side.
The gun is now ready for service.
