Lehigh JHD Manual
CATALOG: JHD-93
JHD CYLINDERS
INSTALLATION & OPERATING INSTRUCTIONS
REMEMBER . . . .
WHEN PERFORMANCE COUNTS
SPECIFY LEHIGH
LEHIGH FLUID POWER, INC.
1413 ROUTE 179
LAMBERTVILLE, NJ 08530
www.lehighfluidpower.com
609-397-3487 • FAX# 609-397-0932 ISSUE DATE 1993
800-257-9515 REVISED 7/05
SHOP ONLINE at www.airlinehyd.com
800-999-7378
JHD CYLINDERS
INSTALLATION AND OPERATING INSTRUCTIONS
LEHIGH FLUID POWER, INC.
1413 Route 179, Lambertville, NJ 08530
TEL: 800-257-9515
609-397-3487 FAX: 609-397-0932
www.lehighfluidpower.com
TABLE OF CONTENTS
.......................................................................................................................................Page
A. Installation ………………………………………………………………….. 1
B. Trouble Shooting …………………………………………………………… 1 & 2
1. Jerky Action ……………………………………………………………… 1
2. Air Leakage ….………………………………………………………….. 1 & 2
a. Loss of Power or No Power ..………………………………………… 1 & 2
b. Evident Leak at Rod Seal …..………………………………………… 2
c. Leak between the Cylinder Tube and End Caps (Heads) …………….. 2
2. Loud Metallic Impact Noise ………………………………………….… 2
C. General Rebuild Instructions ………………………………………………. 3 & 4
1. General Guidelines ………………………………………………………. 3
2. Piston & Rod Assembly w/Miracalube®Lubrication System ……………. 3
3. Final Assembly ………………………………………………………….. 4
D. “ED” Lock Screw - Cylinder Option ……………………………………….. 4
E. Caution Section ………..…………………………………………….………. 5
List of Typical Repair Kit Contents …………………………………………….. 6
Component Torque Chart ……………………………………………………….. 6
Figures 1, 2 and 3 ………………………………………………………………… 7 thru 9
SHOP ONLINE at www.airlinehyd.com
800-999-7378
- 1 -
A. INSTALLATION: (Follow All Safety Lockout/Tagout Procedures)
The cylinder is shipped from the factory with the MIRACALUBE self-lubrication
system (filled at the factory at the time of assembly). It is not necessary to add
grease or other lubrication to the unit prior to installation.
The cylinder is shipped with protective caps in the ports. Do not remove these
caps until the piping is ready for installation. If the cylinder has been in storage
for an extended time, it is advisable to exercise the cylinder; i.e., flex the internal
seals by stroking the piston before installation. Insure the air line used is equipped
with suitable filters, pressure control and a water trap.
Alignment of the piston rod with the work is necessary for the cylinder to operate
satisfactorily and insure long seal and rod bearing life. Be sure all mounting
surfaces are clean, smooth, flat and in alignment. Before finish piping of the
cylinder, stroke the cylinder using the air line to check the mounting arrangement
for misalignment or binding of attached mechanisms. The piston rod should
extend and retract without any unsteady or jerky motion.
If the cylinder is equipped with cushions, adjust the cushion screws to produce the
desired effect for the load, speed and air line pressure to which the cylinders will
be subjected under normal operating conditions.
B. TROUBLE SHOOTING:
1. JERKY ACTION:
Check for misalignment. Look for a bent or scored piston rod. The rod
bushing may be damaged. Check the cylinder tube for dents or bumps.
Confirm that the air cylinder supply pressure and volume are adequate to
operate the cylinder under normal conditions.
2. AIR LEAKAGE:
a. Loss of Power or No Power:
1. Check the air pressure at the machine. Then check the operating
pressure at the control valve for the cylinder and check the line
pressure at the cylinder port(s).
2. Apply air pressure to one port of the cylinder and check for
escaping air from the opposite port or the exhaust port of the control
valve.
SHOP ONLINE at www.airlinehyd.com
800-999-7378
- 2 -
Next attach a small hose with adaptors to the open cylinder port.
Immerse the end of the hose in water, leak detection fluid or soapy
water to simplify this test.
Excessive bubble stream coming from the hose indicates worn or
damaged piston seals or damaged cylinder tube. Both should be
replaced in order for the cylinder to develop full power.
b. Evident Leak at Rod Seal:
The rod bushing assembly may be replaced without disassembly of the
cylinder. Loosen and remove the “ED” (for rod bushing) locking screw if
present. Use a close fitting wrench to remove the rod bushing assembly
from the cylinder by turning counter-clockwise (Figures 2 and 3).
Check the rod seal condition and replace as required. The rod seal is found
at the bottom of the now visible counterbore (Figure 3).
c. Leak between the Cylinder Tube and End Caps (Heads):
Tighten the tie rods to the torque specified in the table on page 6. Be sure
the Open and Closed Heads are properly squared to each other. Check for
the cylinder tube being seated in the tube groove in the face of each head
(Figure 3).
3. LOUD METALLIC IMPACT NOISE—Reference Figure 3:
Check the cushion adjustment. To increase the cushioning effect turn the
cushion screw clockwise (facing the screw driver slot in the cushion screw). If
adjusting the cushion screw does not correct the problem, replacement of the
cushion seal may be required. However, confirm the pressure settings and
operation of externally mounted shock absorbers on the equipment prior to the
replacement of the cushion seal.
When replacing the cushion seal, check the piston for impact damage. If the
piston, piston rod, or rod end shows damage, check the mechanism adjustment
instructions in the machine manual before returning the cylinder to operation.
The cushion seals look like rod and piston seals except the outer body of the
seal is VERY stiff. The outside edge may appear abraded or “sanded.” This is
a sizing process that improves the fit of the seal body in the cavity in the tube
groove side of the head (Figure 3).
SHOP ONLINE at www.airlinehyd.com
800-999-7378
- 3 -
C. GENERAL REBUILD INSTRUCTIONS:
1. GENERAL GUIDELINES:
Remove the cylinder from the equipment and disassemble on a bench or other
clean flat surface.
All necessary parts for the rebuild are contained in the Cylinder Repair Kit for
the specific cylinder used in this equipment.
Clean and inspect all metal parts, particularly the piston rod for wear,
scratches or pitting. Replace the rod if its condition would damage the rod
bushing or seals.
Inspect the piston to piston rod assembly. The piston must be secure on the
piston rod, and the piston nut must be tight. If not, or if there is a question of
the secureness of the assembly, then proceed to the CAUTION SECTION
before continuing with the repair.
2. PISTON & ROD ASSEMBLY w/MIRACALUBE®LUBRICATION
SYSTEM—Reference Figure 1:
On 1.00" to 8.00" bores, apply a thin bead of sealant to the bottom tube
grooves in the Open and Closed Heads. Use either Permatex Form-a-Gasket®
#2 or Locktite® #2 Gasket/Sealant. On 10.00" bore and up, use tube "O"
Rings supplied with kit.
Carefully remove the old piston seals so as not to scratch, nick or burr the lip
or groove of the piston, and gently stretch the new piston seals into the piston
grooves. Be sure that the flat sides of the seals are positioned towards the
center of the piston (Figure 1).
Place the piston and rod assembly in a horizontal position. Remove the
Wicking (Braided Material) and either remove with a sharp hooked scribe or
push all four (4) existing porous plugs into the reservoir. Using the pre-filled
syringe provided, attach the fill nozzle to the syringe with a gentle twisting
motion. Pump about 1/5 of the syringe full into each hole.
Replace the porous plugs with the new plugs provided (some kits may have
one piece of plug material, divide this into four (4) equal lengths). Carefully
press these plug sections fully into the holes. Trim flush, if required with the
bottom of the wicking groove.
Replace the wicking with the new wicking provided being sure the wicking is
stretched tightly. Press the wicking fully into the groove, entirely around the
piston. Trim the excess as necessary with a very sharp knife or side cutters to
form a flush joint.
SHOP ONLINE at www.airlinehyd.com
800-999-7378
Table of contents
