dewald hydraulic pump troubleshooting(Solutions 2023)
Double or triple ESV (2 or 3 rooms)

dewald hydraulic pump troubleshooting(Solutions 2023)

Table of Contents

The troubleshooting process for a dewald hydraulic pump can be quite frustrating. The occurrence of this problem requires consideration of several elements. However, when some of these indications are observed, it is easy to identify the problem. The following are the most common signs of a faulty dewald hydraulic pump.

❗❗❗ Troubleshooting any Direct Current (DC) electrical system should be done with caution and by a trained technician. Anyone unfamiliar with electrical systems should not attempt the troubleshooting procedures listed in this guide.Failure to follow these guidelines could result in personal injury or even death.

Pump assembly key

Pump assembly key is very important. Only by understanding the structure can we troubleshoot better. We will explain it to you in detail through the following pictures.

All All pumps discussed in this manual
1BL 3 or 4 quart assy
2BL 3 or 4 quart with selector manifold assy. 
3Double or triple ESV assy. 
4Quad ESV assy. 
Pump assembly key

Room(s) will not extend, pump does not run

Pump assy.Probable CauseCorrective Action
AlILow or no voltage at pump assemblyVerify that the battery is fully charged and connected to the electrical system.
AlI5 amp fuse blownCheck 5 amp in-line fuse at pump assembly. Replace as necessary.
AlIBad connection of motor ground wie at pumpCheck grounding of black wire coming directly out of 12VDC motor at the pump assembly.
AlIMotor or pump has failedCheck for continuity between blue and black wires of 12VDC motor. lf no cotinuit replace motor. If contiuity is found, then replace pump/motor assembly.
1,2,4Solenoid”A”faultyWith any room extend switch pushed, small post of solenoid “A” should show 12V+.f so, then two large posts of solenoid”A” should have continuity across them. If no contiuity, replace solenoid.
1,2,4No signal to pump assemblyCheck for 12V+ at the pump assembly on the copper buss bar that ties solenoids”A” and”B” together. If power is found, jumper the two large posts on solenoid””A” to see if pump willl run. If pump Tuns then continue trouble shooting system to isolate problem.
3No signal to relay pack from wall switch(es)The blue wire from the wall switches to the relay pack should show voltage when any room extend switch is pressed. If no voltage is found, then replace wali switch(es) as necessary.
3No signal from relay pack to 12VDC motorWith any wall swich pressed, the lug on the relay pack with the blue wire attached should show 12V+. If not, then replace relay pack.
4No signal to solenoid”A” fom cube relayWith any room extend switch pressed, terminal 87a of cube relay should show 12V+. If so, then terminal 30 should show 12V+. If no voltage at 30, then replace cube relay.
dewald hydraulic pump Room(s) will not extend, pump does not run

Room(s) will not extend, pump does run

Pump assy.Probable CauseCorrective Action
AlIL _ow fluid levelFill tank to proper level. See Preventive Maintenance and Recommended Fluids, pg21.
AlIThe siliver, knurled knob on the hand pump is openKnurled knob must be turned clockwise for normal operation.
3,4Faulty coi(s)Check for continuity across the two yellow wires coming out of each of the coils. If no continity replace coil(s)、.
3,4Valve coils miswired Check wiring diagrams. 
dewald hydraulic pump Room(s) will not extend, pump does run

Room extends, but erratically

Pump assyProbable CauseCorrective Action
AlIRoom is out of synchronizationSee “cable adjustment, pg 20.
AlIRoom seals or rails dryLubricate room seals and rails with slicone spray.
AlIInternal leak in slide room cylinderSee diagnosing a Dewald cylinder for internal leakage” ,p9 19.
Room extends, but erratically

Pump does not shut off when extend switch is released

Pump assyProbable CauseCorrective Action
1,2,4Solenoid“A”faultyRemove blue wire from large top post of solenoid“A”.Test across the two large posts of solenoid“A”for continuity while the extend switch is pressed.If continuity remains after switch is released, then replace
solenoid.
1,2,4Faulty switchRemove blue wire from large top post of solenoid“A”.Check for voltage at small bottom post of solenoid“A”while the extend switch is pressed.If voltage remains after switch is released, then replace switch.
3Relay pack faultyRemove large blue wire from lug of relay pack.Test across that lug and the center lug(red wire) for continuity while the extend switch is pressed.If continuity remains after switch is released, then replace
relay pack.
3Faulty switchRemove large blue wire from lug of relay pack.Check for voltage at blue wire in relay pack coming from switches while the extend switch is pressed.If voltage remains after switch is released, then replace switch.
Pump does not shut off when extend switch is released

Wrong room extends

Pump assyProbable CauseCorrective Action
2Wrong selector knob chosenChose correct selector knob.
2Faulty selector knobRemove selector knob from manifold assembly and inspect the end for damage or contamination. Swap with a known good valve on manifold. If symptom swaps, then replace selector knob. If symptom does not swao, then continue troubleshootina to isolate defective comoonent.
2, 3,4Cylinders plumbed to manifold incorrectlyCheck plumbing of cylinders (See hydraulic diagrams, pg. 17)
3, 4Stem valves are in manual override positionTurn slotted set screws at tlhe end of the valves counterclockwise until they stop. If system has red knobs instead of set screws, turn knobs until they “snap” back into position (see oo 6).
3, 4Coils and/or switches wired incorrectlyCheck wiring of coils and switches according to the wiring diagrams contained in this manual.
3, 4Faulty stem valveSwap suspected stem valve with a known good stem valve on manifold. If symptom swaps, replace stem valve. If stem valve has red knurled knob on the end (old style), then valve and coil must be replaced.
Wrong room extends

Room “creeps” back in once extended

Pump assyProbable CauseCorrective Action
AllA leak somewhere in systemCheck all hoses, hose connections, pump assembly, etc for any visible
fluid leak. Repair any found leaks as necessary.
AllAir trapped in systemVerify that hose connection ports on cylinder are pointing as close to 12
o’clock as possible. Cycle room(s) to complete extension and retraction
allowing system to rest 5 minutes in-between cycles. Do this 4 times.
This should purge the air from the system
AllBad piston seal in cylinder(s)Test for internal cylinder seal leakage per instructions on pg 19.
AllBad o-ring seal between hand pump and pump
assembly
Install o-ring kit #800176 as per pg 22.
AllThe silver, knurled knob on the hand pump is
open
Knurled knob must be turned clockwise for normal operation.
1Bad piston seal in cylinder(s)On the BL 4 quart pump assembly where 2 or more rooms are teed
together, a bad cylinder on one room can make another room creep
back in. Be sure to check all cylinders for internal piston seal leakage on
these systems
3, 4Stem valves are in manual override positionTurn slotted set screws at the end of the valves counterclockwise until
they stop. If system has red knobs instead of set screws, turn knobs
until they “snap” back into position (see pg 6).
3, 4Faulty stem valveSwap suspected stem valve with a known good stem valve on manifold.
If symptom swaps, replace stem valve. If stem valve has red knurled
knob on the end (old style), then valve and coil must be replaced.
Room “creeps” back in once extended

Room(s) will not retract, pump does not run

Pump assy.Probable CauseCorrective Action
AllLow or no voltage at pump assemblyVerify that the battery is fully charged and connected to the electrical
system.
All5 amp fuse blownCheck 5 amp in-line fuse at pump assembly. Replace as necessary.
AllBad connection of motor ground wire at pumpCheck grounding of black wire coming directly out of 12VDC motor at
the pump assembly.
AllMotor or pump has failedCheck for continuity between blue and black wires of 12VDC motor. If
no continuity, replace motor. If continuity is found, then replace
pump/motor assembly.
1, 2, 4Solenoid “B” faultyWith any room retract switch pushed, small post of solenoid “B” should
show 12V+.If so, then two large posts of solenoid “B” should have
continuity across them. If no continuity, replace solenoid.
1, 2, 4No signal to pump assemblyCheck for 12V+ at the pump assembly on the copper buss bar that ties
solenoids “A” and “B” together. If power is found, jumper the two large
posts on solenoid “B” to see if pump will run. If pump runs then
continue trouble shooting system to isolate problem.
3No signal to relay pack from wall switch(es)The green wire from the wall switches to the relay pack should show
voltage when any room retract switch is pressed. If no voltage is found,
then replace wall switch(es) as necessary.
3No signal from relay pack to 12VDC motorWith any wall switch pressed, the lug on the relay pack with the green
wire attached should show 12V+. If not, then replace relay pack.
4No signal to solenoid “B” from cube relayWith any room retract switch pressed, terminal 87a of cube relay should
show 12V+. If so, then terminal 30 should show 12V+. If no voltage at
30, then replace cube relay.
Room(s) will not retract, pump does not run

Room(s) will not retract, pump does run

Pump assyProbable CauseCorrective Action
AllLow fluid levelFill tank to proper level. See Preventive Maintenance and Recommended Fluids, pg 21.
AllSystem overfilled with fluidDrain tank to proper level. See Preventive Maintenance and Recommended Fluids, pg 21.
3, 4Faulty coil(s)Check for continuity across the two yellow wires coming out of each of the coils. If no continuity, replace coil(s).
3, 4Valve coils miswiredCheck wiring diagrams.
Room(s) will not retract, pump does run

Room retracts, but erratically

Pump assyProbable CauseCorrective Action
AllRoom is out of synchronizationSee “cable adjustment”, pg 20.
AllRoom seals or rails dryLubricate room seals and rails with silicone spray.
AllInternal leak in slide room cylinderCheck cylinder for internal piston seal leakage. See “diagnosing a Dewald cylinder for internal leakage” , pg 19.
Room retracts, but erratically

Pump does not shut off when retract switch is released

Pump assyProbable CauseCorrective Action
1, 2, 4Solenoid “B” faultyRemove green wire from large top post of solenoid “B”. Test across the two large posts of solenoid “B” for continuity while the retract switch is pressed. If continuity remains after switch is released, then replace solenoid.
1, 2, 4Faulty switchRemove green wire from large top post of solenoid “B”. Check for voltage at small bottom post of solenoid “B” while the retract switch is pressed. If voltage remains after switch is released, then replace switch.
3Relay pack faultyRemove large green wire from lug of relay pack. Test across that lug and the center lug (red wire) for continuity while the retract switch is pressed. If continuity remains after switch is released, then replace relay pack.
3Faulty switchRemove large green wire from lug of relay pack. Check for voltage at green wire in relay pack coming from switches while the retract switch is pressed. If voltage remains after switch is released, then replace switch.
Pump does not shut off when retract switch is released

Wrong room retracts

Pump assyProbable CauseCorrective Action
2Wrong selector knob chosenChose correct selector knob
2Faulty selector knobRemove selector knob from manifold assembly and inspect the end for damage or contamination. Swap with a known good valve on manifold. If symptom swaps, then replace selector knob. If symptom does not swap, then continue troubleshooting to isolate defective component
2, 3, 4Cylinders plumbed to manifold incorrectlyCheck plumbing of cylinders (See hydraulic diagrams, pg. 17)
3, 4Stem valves are in manual override positionTurn slotted set screws at the end of the valves counterclockwise until they stop. If system has red knobs instead of set screws, turn knobs until they “snap” back into position (see pg 6).
3, 4Coils and/or switches wired incorrectlyCheck wiring of coils and switches according to the wiring diagrams contained in this manual.
3, 4Faulty stem valveSwap suspected stem valve with a known good stem valve on manifold. If symptom swaps, replace stem valve. If stem valve has red knurled knob on the end (old style), then valve and coil must be replaced.
Wrong room retracts

Room “creeps” back out once retracted

Pump assyProbable CauseCorrective Action
AllA leak somewhere in systemCheck all hoses, hose connections, pump assembly, etc for any visible fluid leak. Repair any found leaks as necessary.
AllAir trapped in systemVerify that hose connection ports on cylinder are pointing as close to 12 o’clock as possible. Cycle room(s) to complete extension and retraction allowing system to rest 5 minutes in-between cycles. Do this 4 times. This should purge the air from the system.
AllBad piston seal in cylinder(s)Test for internal cylinder seal leakage per instructions on pg 19.
AllBad o-ring seal between hand pump and pump assemblyInstall o-ring kit #800176 as per pg 22.
AllThe silver, knurled knob on the hand pump is openKnurled knob must be turned clockwise for normal operation.
1Bad piston seal in cylinder(s)On the BL 4 quart pump assembly where 2 or more rooms are teed together, a bad cylinder on one room can make another room creep back out. Be sure to check all cylinders for internal piston seal leakage on these systems.
3, 4Stem valves are in manual override positionTurn slotted set screws at the end of the valves counterclockwise until they stop. If system has red knobs instead of set screws, turn knobs until they “snap” back into position (see pg 6).
3, 4Faulty stem valveSwap suspected stem valve with a known good stem valve on manifold. If symptom swaps, replace stem valve. If stem valve has red knurled knob on the end (old style), then valve and coil must be replaced.
Room “creeps” back out once retracted
kefu

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dewald hydraulic pump parts

Within the context of this article, if you desire DEWALD pump parts, then you are at the right place. We have all Dewald hydraulic pump parts you need such as motor housing and motor seals among others. As the exclusive distributor of Dewald pumps, we have in stock the best quality parts available on the market today. Our engineers collaborate with customers for design of practical solutions to mining and other similar difficult situations prevailing in heavy-duty industries. Furthermore, we hold a vast stock of DEWALD replacement accessories that can be dispatched quickly to any part of the world.

dewald hydraulic pump parts
dewald hydraulic pump parts
  • Return all rooms and leveling legs to the travel/storage position.
  • For the coach, disconnect its battery and for the pump system, disconnect the battery too.
  • Use a pipe to suck out oil from the tank.
  • Each wire or hose should be marked according to its position.
  • Remove each hose from the pump assy. and insert them into a bucket if they spring a leak.
  • Disconnect power line (green, blue, black) from pump motor
  • Unscrew pump mounting bracket and take it on clean workbench where there is enough light so that you can disassemble it properly.
  • Take off tank; empty any remaining fluid out of it by using a lint free cloth to clean inside of tank
  • Get rid of two nuts and lock washers in order to remove hand pump from assembly. This can be difficult since inlet strainers are still attached. After this comes off of hollow tubes pull hand pumps down around antennae after which look at strainers before pulling farther along the tubes.
  • To check tightness through holes in hollow tubes for right thread use small size Allen wrench long enough (right hand thread).
  • Clean parts before you put them back together again
  • Put two new o rings (VA25400) on each tube(4 total), lube with Dexron III
  • Re-install Hand Pump onto Pump Assy.
  • Get one white o-ring (VA20000) on each tube. Push assembly as far as possible toward housing aligning housing and tubes so that o-rings seat properly in grooves.
  • Tighten nuts on tubes 70 inch/ pounds torque specification
  • Install new o-rings (VA14350 and VA25300, 1 each). Re-install tank on top of hand pump assembly.
  • Replace all components removed during disassembly but make sure to match up hose/wire markings made earlier
  • Fill Dexron III fluid to ½” below top of tank.
  • Extend rooms or leveling legs fully, wait 30 seconds, and retract rooms or leveling legs. Repeat this 4 times. By doing this air should be completely removed from the system.
  • With all rooms and jacks retracted, check fluid level in tank. Add as necessary to bring to proper level.
  • Try out the system for correct functioning; see if it is leaking etc.
Part #DescriptionColorABCDE
130-11551.5×24 extBlack25.251.7518.37.7575
130-11561.5x 24 non extBlack25.251.756.75.75.75
130-11571.5×41 extBlack42.251.7518.37.7575
130-12261.5X 42 non extBlack45.251.757.0.75.75
130-1159 i i1.5x 38 extBlack42.251.7518.37.7575
CW103202x 24 non extGreen25.02.387.0.75.75
CW10323S2x 32 non extYellow32.752.387.0.7575
cw1 0324S2x 32 non extYellow33.02.387.0.7575
+CW10325S2×38 non extGray_39.02.387.0.75.75
CW1 0326S2x 38 extGray39.02.3818.37.7575
*CW103272×40 non extGreen41.02.387.0.75.75
CW103292×48 non extYellow49.02.387.0.7575
*CW104002 x40 (Dutchmen)Black36.752.387.75.75
CW104161.125x 16.5 non extBlack17.381.382.75.625.625
+CW104201.5x 20 non ext23.51.8753.5.75.75
+CW105002×44 non extBlue45.02.387.0.75.75
+CW105201 5x 20 nonextGray23.12t 1.757.25.75.75
CW10524S1.5 x 24 non extGray27.51.757.0.625.75
+CW105341.5x 34 non extBlack_37.121.757.25.75.75
+CW105381.5x 38 non ext39.251.387.0.75.75
+CW106201.5x 20 non ext23.51.887.25.625.625
CW106381.5x 38 non extPurple39.251.756.75.75.75
CW106401.5×40 non extGreen41. 251.757.0.75.75
CW107191.5x 19 extBlue20.251.7518.62.75.75
CW107201.5×20 non extGray_20.881.757.12.75.75
+CW107241.5 x24 non extGreen25.251.757.0.7575
CW107261.5x 26 extRed27.251.7518.62.75.75
CW107291.5x 29 non extRed30.251.754.0.75.75
CW107321.5×32 extYellow33.251.7518.62.75.75
+CW107381.5x 38extGray39.251.7518.62.75.75
+CW107411.5×41 extBlue42.251.7518.62.75.75
+CW108201.5x 20 non extPurple20.881.753.5.75.75
+CW108241.5×24 extGreen25.251.7518.62.7575
DN118161.5x 40(Dutchmen)_Black40.51.753.18.75
*DN11997S1.5×38Black41.51.757.0.625.625
+CW101202×3233.02.387.01.12n/a
*CW101402×17Black18.02.387.01.12n/a
CW10175S2×24Red25.02.387.01.12n/a
+CW102002×32Yellow33.02.387.01.12n/a
CW10300S2×3839.02.387.01.12n/a
CW104102x 44Gray45.02.387.01.12n/a
dewald hydraulic pump parts

dewald hydraulic pump troubleshooting video

dewald hydraulic pump troubleshooting FAQ

If you’re looking for information about dewald hydraulic pump troubleshooting FAQs, you’ve found the right place. Here you’ll find loads of practical tips and hints to get you started with a new business or to help you grow your existing one.

what type of hydraulic fluid for dewald slide out pump?

Synthetic Hydraulic Fluids

These fluids are made from chemicals such as ester or phenol and have been used in place of petroleum based oils for a number of years now. These fluids have a number of advantages over the conventional mineral oil based fluids including:

Higher temperature range – They are able to operate at higher temperatures than their petroleum counterparts, making them ideal for use with high temperature machinery such as the DeWalt slide out pump;

Better lubricity – Synthetic fluids possess higher lubricity than their traditional mineral oil counterparts, meaning they are less likely to cause wear on moving parts;

Reduced fluid degradation – Synthetic fluids do not degrade at the same rate as mineral oils do when exposed to sunlight or UV light (due to their chemical makeup);

dewald hydraulic pump manual can be found there?

We provide you with a very professional manual, click the link below to download it for free!
Dewald hydraulic pump manual

dewald hydraulic pump Slide out not working?

The Dewalt slide-out works fine when it’s at full extension. But if you try to retract it, it just stops and won’t go back in. I’ve checked all of the hoses and they all seem to be connected. The only thing that is different than when I first bought it is the fluid level hasn’t gone down since I filled it up about a year ago. There was no leakage or anything like that involved with filling the fluid, so I don’t think there’s a leak in the system.

The pump is probably overfilled with oil and not draining properly. Try removing some oil from the reservoir using a turkey baster or similar device until you’re sure that there’s enough room for air to enter before starting up again (you can always put more back in later if needed).

Dewald hydraulic pump failed?

In the photo below, the red arrow points to the failed Dewald hydraulic pump. This failure occurred after only 3 years of operation. The pump runs on a shaft that is connected to the engine crankshaft by means of a crank pulley. When this pump fails, it usually means that the crankshaft is bent and must be replaced as well as the hydraulic pump.

The part number for this particular Dewald hydraulic pump is HC-2S-A-112-0210. The model number is HC-2S-A-112-0210 and it has 2 cylinders with a stroke length of 1″ (25mm). Each cylinder has an operating pressure rating of 3000 psi (207 bar). The maximum flow rate for each cylinder is 6 GPM (26 L/min).

Hi all! I hope you found this post to be helpful. If you have any questions, or would like advice on a different hydraulic pump please feel free to contact us and we can connect you with the technician who specializes in that pump type. Thanks!

Related Questions

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An external fuel pump moves gasoline from the tank to the engine, often using an impeller or gear-rotor mechanism to create pressure that propels the fuel through the line.

How do you calculate efficiency for a gear pump?

To calculate the efficiency of a gear pump, you must measure the input power and the output power, and then divide the output power by the input power. This ratio is then multiplied by 100 to get the efficiency percentage.

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Hydraulic Pump Enginee Lee

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