HTL DS Series, Operating Instructions Manual

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18

Troubleshooting

Symptom

Probable Cause

Action Required

Gauge shows 

pressure 

build-up but 

the tool will 

not cycle.

1. 

Couplings loose or 
inoperative.

2. 

Solenoid inoperative.

1. 

Tighten and/or replace couplings. 

2. 

If solenoid is bad, replace.

Cylinder will 
not retract.

1. 

Voltage to electric 

pump is too low to line 

drop or inadequate 

amperage is available.

2. 

Linkage between 

piston rod and drive 

arms are broken.

1. 

Get shorter extension cord. If shop power is adequate, draw power 

from welding machine or cal rod transformer.

2. 

Replace part as necessary 

Wrench 

pressure will 

not build.

1. Oil blow by in wrench 

    (Piston seal leak,  

    blown O-ring, cracked  

    piston).

2. Pump problem.

1. 

Replace defective parts. Return to HTL.

2. 

Check to see if sub plate is worn. Remove screws from pump motor 

to reservoir, slide pump motor to the side, turn pump on and while 

holding down on the button, put your finger on the dump tube (round 

tube under the directional control valve) if you feel pressure, then 

replace the subplate and shear seals.

3. 

Check to see if you have leaks from the external relief valve and the 2 

oil line connections (bottom of relief valve and connection into pump 

body’s other end) of oil line. If leaking, retighten with 9/16” open end 

wrench. Return to HTL.

4. 

If pump sounds like there is rattling in the air motor, take pump to 

your local HTL office or Distributor.

5. 

Air Pumps - Faulty air valve due to excessive moisture and/or dirt 

in air supply. Disassemble air valve and wipe any residue from air 

valve piston. Spray brake cleaner into air valve body, dry thoroughly. 

Disassemble all small air lines and blow out with compressed air. 

Lubricate both air valve piston and body with hydraulic oil (sparingly) 

and reassemble. Return to HTL.

6. 

Air pumps - Faulty.

HTL-Operating-Instructions-DS.indd   19

11/04/2017   10:15