BLACKMER LDF1A, Installation, Operation And Maintenance Instructions

501-

F

00    Page 8/12 

MAINTENANCE 

PUMP ASSEMBLY 

Before reassembling the pump, inspect all component parts 
for wear or damage, and replace as required. Wash out the 
bearing/seal recess of the head and cylinder and remove any 
burrs or nicks from the rotor and shaft. 

1.  Position the pump cylinder (12) with the bearing side up. 

2.  Apply a small amount of quality O-ring lubricant in the 

seal and bearing recess of the cylinder to facilitate 
mechanical seal (153) installation. 

3.  Insert the seal jacket assembly (153A) into the seal 

recess of the cylinder with the drive tangs of the jacket 
inward. 

4.  With the polished face outward, align the notches of the 

rotating seal face with the jacket, and install the seal face 
(153F) and O-ring (53G) into the jacket assembly. After 
installation, clean the seal face with a clean tissue and 
alcohol. 

5.  Clean the polished face of the stationary seat (153B) with 

a clean tissue and alcohol. 

6.  Install new O-ring (153D) onto stationary seat (153B). 

7.  Align the notch in stationary seat (153B) with the anti-

rotation pin in the cylinder (12) and insert it into the seal 
recess with the polished face inward to mate with the 
rotating face. 

8.  Hand pack the ball bearing (24) with grease. Refer to 

"Lubrication" in the Pump Maintenance Section for the 
recommended grease. 

9.  Install the bearing (24) into the cylinder recess. The 

bearing balls should face outward, with the grease shield 
inward. Ensure that the bearing (24) is fully and squarely 
seated against the mechanical seal (153). 

10.  Keep the bearing (24) from falling out of the cylinder (12) 

by securing with one of the bearing cover capscrews (28) 
and a washer that will catch the outer ring of the bearing 
when tightened. 

11.  Turn the pump cylinder (12) over with the INTAKE port 

and relief valve to the 

right

.   

12.  Apply a light coating of quality O-ring lubricant to the non-

driven shaft end. 

13.  Insert the shaft, short end first, into the cylinder (12).  

Carefully slide the shaft through the installed mechanical 
seal (153) and bearing.  Align the notch in the rotor with 
the drive tang on the seal jacket of the mechanical seal.  
Rotate the shaft to ensure the drive tangs of the 
mechanical seal are engaged in the notches in the rotor. 

14.  Install lockwasher (24B) on the shaft protruding through 

the bearing in the cylinder with the tangs outward.  
Ensure the inner tang “A” of the lockwasher is engaged in 
the slot in shaft threads. Bend it slightly, if necessary. 
(See Figure 8.) 

15.  Install locknut (24A) onto threads of shaft with the 

tapered end inward.  

16.  Tighten the locknut (24A) with a spanner wrench to pull 

the rotor flat against the back wall of the cylinder. DO 
NOT overtighten the locknut and bend or shear the inner 
tang. Adjustment to the locknuts will be made after the 
head is installed. 

17.  Insert the vanes (14) into the slots in the rotor, ensuring 

that the relief groove is facing toward the direction of 
rotation See Figure 6 

18.  Apply a light coating of quality O-ring lubricant in the seal 

and bearing recess of the head (20) to facilitate 
mechanical seal (153) installation. 

19.  Insert the seal jacket assembly (153A) into the seal 

recess of the head with the drive tangs of the jacket 
inward. 

20.  With the polished face outward, align the notches of the 

rotating seal face with the jacket, and install the seal face 
(153F) and O-ring (53G) into the jacket assembly. 

21.  Clean the polished face of the stationary seat (153B) with 

a clean tissue and alcohol. 

22.  Install new O-ring (153D) onto stationary seat (153B). 

23.  Align the notch in stationary seat (153B) with the anti-

rotation pin in the head (20).  Insert it into the seal recess 
with the polished face inward to mate with the rotating 
face. 

24.  Hand pack the ball bearing (24) with grease. Refer to 

"Lubrication" in the Pump Maintenance Section for the 
recommended grease. 

25.  Install the bearing (24) into the head recess. The bearing 

balls should face outward, with the grease shield inward. 
Ensure that the bearing (24) is fully and squarely seated 
against the mechanical seal (153). 

26.  Apply a small amount of quality O-ring lubricant to the O-

ring groove on the inside face of the head and install a 
new head O-ring (72) in the groove by laying the O-ring 
flat and starting in on one side of the groove, stretching 
ahead with the fingers, as shown in Figure 7. 

Figure 7 Head O-ring Installation 

27.  Apply a light coating of quality O-ring lubricant on the 

shaft to facilitate head installation. 

28.  With the tell-tale hole towards the bottom of the pump, 

carefully install the head assembly (20) over the shaft 
and against the cylinder (12). Use care not to damage 
the mechanical seal components.  Align the drive tangs 
of the mechanical seal with the notches in the rotor. 

29.  Rotate the head (20) to engage the drive tangs of the 

seal jacket with the slots in the rotor. 

30.  Install and finger tighten the head capscrews (21). The 

head capscrews will be fully tightened after the second 
locknut is installed. 

31.  Install lockwasher (24B) on the shaft protruding through 

the bearing in the head with the tangs outward.  Ensure 
the inner tang “A” of the lockwasher is engaged in the 
slot in shaft threads. Bend it slightly, if necessary. (See 
Figure 8.) 

32.  Install locknut (24A) onto threads of shaft with the 

tapered end inward.