Graco D, Operation, Parts, Service And Repair

Repair

311320G

23

a. Remove ball and spring assembly. Hold 

ball and unscrew assembly. If dirt or 
material build-up prevents complete 
removal of the spring, screw it back in. 
Soak assembly in gun cleaner and try to 
remove it again. If ball and spring 
assembly cannot be removed undam-
aged, replace it.

b. Use check valve cleanout drill to clean 

inside of closure screw. Insert the flat-
tened end of cleanout drill into opening 
at end of screw, avoiding spurs in the 
closure screw. Do not spin drill until the 
flat on the drill has cleared spurs. Spin 
drill with your fingers to loosen any 
buildup, then remove drill and flush 
inside of screw with gun cleaner. Next, 
check area where ball seats for dam-
age. Also check sleeve for damage; it 
should fit tightly on the end of the screw. 
If there is damage or if the sleeve fits 
loosely, replace it. Replace sleeve if 
check valve can be threaded all the way 
into gun block by hand. A good check 
valve requires the use of a 5/16 in. nut 
driver to make the last 1/4 turn, com-
pressing the sleeve. This compression 
is required to create an internal seal in 
the gun block.

c. Remove damaged check valve sleeve. 

Remove ball and spring. Insert check 
valve into check valve sleeve removal 
block (F

IG

. 24). While holding block, and 

keeping pressure on head of check 
valve, slice check valve sleeve with 
razor knife at a 10 - 15 degree angle rel-
ative to the plane of removal block. 
Remove check valve from block and 
peel sleeve off. If check valve sleeve 
remains in gun block after removing 

check valve, use extractor tool to 
remove sleeve. Insert threaded end of 
tool into cleanout port and, while press-
ing tool into gun block, turn it clockwise 
several times. Withdraw tool from gun 
block; sleeve should slide out with tool.

F

IG

. 24: Sleeve Removal Block

d. Insert spring assembly into check valve 

and turn the screw clockwise. When the 
spring is fully inserted, stem will jump 
over spurs in screw and make clicking 
sound. Ensure ball fully seats in check 
valve. If not, or ball is damaged, replace 
with new ball and spring assembly.

14. Remove retaining ring, washer, and felt 

wiper from retainer. Flush retainer with gun 
cleaner, insert new felt wiper and washer, 
then install retaining ring. Loosely thread 
felt wiper retainer into rear of mixing cham-
ber (DO NOT TIGHTEN). If not installing to 
gun block, store assembly in plastic vial 
with corresponding cleanout spade.

Check Valve Sleeve

Insert Check Valve