Graco GT 750, Instructions Manual

Page: 8 / 18

Service
8 3A5363B
Service
Before You Start
• Be sure you have all necessary parts on hand. Use
Graco repair kit 25D511. Use all parts in the kit for
best results.
• Parts included in the kit are marked with one aster-
isk, for example (19*), in the text and drawings.
• Clean and inspect all parts for wear or damage as
you disassemble them. Replace parts as needed.
• For best results, always use all new parts included
in kit to replace all the o-rings and packings when
you disassemble the pump.
Displacement Pump Service
Disassembly
1. Flush the pump.
2. Relieve pressure , page 6.
3. Disconnect fluid and air lines from pump and
remove pump from its installation location.
4. Clamp the air motor base (21) in a vise horizontally
by closing the vise jaws on the flange.
5. Insert a wrench through a slot in the foot valve (10)
and secure it around the flats of the piston shovel
rod (8). While holding the piston shovel rod securely
in place, use a second wrench to loosen and
remove jam nut (15). Remove washer (28), and
priming plate (14) from shovel rod (F
IG
. 3).
NOTE: Using a wrench to hold the piston shovel rod
(8) in place during this procedure will prevent it from
unscrewing from the piston housing (7).
6. Unscrew foot valve housing (10) from cylinder (20)
(F
IG
. 4).
NOTE: Poppet check (12), foot valve packings (13),
and bearing (11) slide off priming rod (8) when
removing foot valve housing.
F
IG
. 3
F
IG
. 4
15 28
14*
10
8
20
10
8