Discussion:
Overheating Main Hyd. Pump

I have a Daewoo GC25S-3 95-00415. The main hyd. pump overheats after only 5 min. of use, no load and at idle.

Can't touch the pump after 15 min. of use, forks lift slow, and engine lugs down.

No restriction in high pressure line from pump to control valve, and no restriction thru control valve to tank.

Can that pump go bad and overhear????

Thanx
  • Posted 7 Aug 2012 11:40
  • By harold_c
  • joined 19 May'11 - 11 messages
  • Maryland, United States
Showing items 1 - 8 of 8 results.
unbolt the flex plate from the flywheel and see if the engine revs up, sounds like a torgue converter going bad. If that doesnt make a difference can you check to see if the hydraulic control valve is overheating too. It or the pump may have a relief valve stuck open and constantly dumping fluid over relief will make oil over heat quickly.
  • Posted 11 Aug 2012 06:39
  • By bigGlittlestar
  • joined 12 Aug'08 - 139 messages
  • United States
Swoop, if you ever get opportunity to jump, try it, you'll never be the same.
(JUST FOR YOUR INFO, SWOOP REFERS WHEN A JUMPER UNDER CANAPY FLIES IN AT 90 mph AND SKIDS THE GROUND AT 1 ", OR FREEFALLING INTO A FORMATION THATS BUILDING AT A HIGH RATE OF SPEED AND SLOWING DOWN QUICKLY TO GET IN)
There are 2 decent drop zones in NC, one near Raleigh and one near Charlette. Also there is a wind tunnel near Raleigh, if you lack the intestinal fortitude for a skydive, but if you can, do it. My addiction has drawn me to the DZ every weekend for the last 10 years.

Harold, can you remove the pump and run the truck?
  • Posted 11 Aug 2012 04:43
  • By 7777
  • joined 8 Mar'11 - 649 messages
  • New York, United States
thanks for the assistance. JCFORKLIFT@gmail.COM
7777,
nope dont skydive but always wanted to try it
i picked this name up after watching that movie "dropzone" with wesley snipes in it. The crazy guy that was on thier jump team they called swoop. ;o)

anyways,
harold
if you have removed the pressure line and checked flow and with no restriction on the pump the engine still will not rev up i have a couple questions

1- was the engine laboring during this test like it was trying to rev but something was holding it back?
2- are there any codes or warning lights on the dash lighting up or showing error codes?
you may have more than one issue here but the fact that the pump is heating up and it is mounted on the transmission makes me wonder if there is something in the transmission causing this problem and its translating out to the pump and throwing you off.
you may wind up going into the transmission from the sounds of it
  • Posted 11 Aug 2012 02:42
  • By swoop223
  • joined 23 Mar'12 - 3,691 messages
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com
Worn parts or bad bearing in the pump?

Hey swoop, do you jump, are you a skydiver? Thats a comman term we use (swoop) in the sport.
  • Posted 9 Aug 2012 18:25
  • By 7777
  • joined 8 Mar'11 - 649 messages
  • New York, United States
thanks for the assistance. JCFORKLIFT@gmail.COM
In addition I have removed pressure line from hyd. pump to control valve, put hose in clean bucket, oil flows freely, but engine still will not rev.

The other section of the pump which connects to the brake valve?? , I have not done anything with.

There also seems to be a reliefe valve built into the hyd. pump.
Again I awaiting a diagram from the dealer.
  • Posted 9 Aug 2012 11:27
  • By harold_c
  • joined 19 May'11 - 11 messages
  • Maryland, United States
Pump is mounted on trans. The pump has two sections, one section supplies oil to the control valve, and the other section supplies oil to the hyd. brakes. I am awaiting a hose diagram from local dealer.

Engine will not rev and oil gets to hot to touch within 15 mins.
  • Posted 9 Aug 2012 11:19
  • By harold_c
  • joined 19 May'11 - 11 messages
  • Maryland, United States
where is this pump mounted at?
on the engine or transmission?
or in the counterweight, with pilotshaft driving it off the engine front pulley? if in counterweight how close is the muffler to it?
  • Posted 9 Aug 2012 03:08
  • By swoop223
  • joined 23 Mar'12 - 3,691 messages
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com
I'm not familiar with your particular machine, but I've never had a pump go bad where the symptom was heat. I've always found heat to be a symptom of a restriction to flow.

I'd make a hose up to go from the hyd pump directly to the hyd tank fill & just let the unit run. If the pump still got hot then maybe it is bad- there's always a first.
  • Posted 8 Aug 2012 23:05
  • By bbforks
  • joined 1 Mar'12 - 1,437 messages
  • Pennsylvania, United States
bbforks (at) Hotmail (dot) com
Customers love technology- until they have to pay to fix it!

Post your Reply

Forkliftaction accepts no responsibility for forum content and requires forum participants to adhere to our rules of conduct. Click here for more information.

If you are having trouble using the Discussion Forums, please contact us for help.

Latest job alerts …
Movers & Shakers
Mike Barker Mike Barker
President and CEO Swisslog Americas, Swisslog
Vice president, Newgentech Material Handling India
Sales representative, Alabama and Panama City, Thompson Lift Truck
Chief marketing officer, Bobcat Company
Latest job alerts …
Fact of the week
The origin of "love" as the score zero in tennis is debated, but two main theories prevail. One suggests it's derived from the French word "l'oeuf" (egg) which resembles the shape of the number zero. The other proposes it's related to the Dutch word "lof" meaning "honour" as players might be playing for honour when scoreless.