Discussion:
Linde H25T Speed & Acceleration Issues

We have a Linde H25T 393 Series Truck that will not achieve top speed and comes to stop at 70% or Greater Throttle.

No Error Codes
LHC was been reprogrammed and swapped with a known good unit.
Hydrostat has been replaced.
brake valve has been replaced and the 1 drive motor has been replaced.
hydraulic control valve has also been replaced.
Engine ECU Was also replaced.
Pressure checks out. Local Dealer is clueless.
Parts Not Replaced: Right Drive Motor, Accelerator Pot (accel pot has been calibrated)

The only thing we have seen is when the fwd or rev solenoid is activated our top voltage is ~6.5 and will drop off at full throttle.

Please Help!

what voltage does the LHC normally put out to the solenoids and how can we trouble shoot this

howitt937 at gmail dot com
  • Posted 22 Aug 2013 10:24
  • Modified 22 Aug 2013 10:28 by poster
  • By Howitt
  • joined 13 Feb'09 - 80 messages
  • Ohio, United States
Showing items 1 - 18 of 18 results.
Hello, I have the exact same problem. The forklift starts to run well until it exceeds half of the accelerator pedal. That's when it starts to lose power but the engine accelerates well. I have changed the potenciometer, engine rpm sensor and it remains the same. I've found that translational solenoids lower the voltage when you do that. It does so both ways. It has changed all the filters and hydraulic oil. It does not fail on the console. If the belt is incorrectly synchronized, how does the LHC module detect it?
  • Posted 22 Aug 2024 08:22
  • By Snaider_84
  • joined 20 Jun'24 - 5 messages
  • Spain
I was gonna suggest turbo failure
  • Posted 26 Aug 2013 16:07
  • By kevin_k
  • joined 25 Nov'05 - 502 messages
  • dumfriesshire, United Kingdom
Do we know what engine code it is?
  • Posted 26 Aug 2013 00:59
  • By Forkingabout
  • joined 31 Mar'11 - 862 messages
  • england, United Kingdom
you say timing jumped 3 teeth in that VW engine?

well you better be checking the valves in the head then
those engines had almost zero tolerance in the head and valve train and if the timing got off any at all there was valve damage pretty much 100% of the time.

if and i mean IF that engine is running well it wont be for long
we've done too many of these in our shop to know better than to assume everything is ok inside it after something like that
  • Posted 25 Aug 2013 06:24
  • By swoop223
  • joined 23 Mar'12 - 3,691 messages
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com
in the USA you can buy parts individually, we normally replace them at the same time.

Per the service records it was replaced few years but we weren't maintaining the unit at the time it was supposedly replaced.

we replaced belt, tensioner and waterpump for piece of mind.
  • Posted 25 Aug 2013 01:47
  • Modified 25 Aug 2013 01:48 by poster
  • By Howitt
  • joined 13 Feb'09 - 80 messages
  • Ohio, United States
Was tensioner replaced at same time when the timing belt was replaced?

Over here in UK they come as a kit, can't get timing belt on its own.
  • Posted 25 Aug 2013 01:23
  • By Forkingabout
  • joined 31 Mar'11 - 862 messages
  • england, United Kingdom
Problem solved. Timing belt tensioner failed & became loose and belt jumped ~3 teeth.(last timing belt was 1800 Hrs) ECU was putting LHC in to a limp mode due to low vacuum & running rich at higher rpms but would not throw a code. Its hard to believe a truck would start nearly instantly and rev up could be 3 teeth off. Thanks for all the help guys
  • Posted 25 Aug 2013 01:13
  • By Howitt
  • joined 13 Feb'09 - 80 messages
  • Ohio, United States
I would replace the accelerator potentiometer as well as the 2 plastic gears. If there is ANY play in the gears it will cause this problem plus the gears are really inexpensive.
  • Posted 23 Aug 2013 21:35
  • By duodeluxe
  • joined 11 Feb'05 - 923 messages
  • United States
duodeluxe
Yes, this is definitely an electronics problem. Faulty hydrostatic transmission (usually the internal leakages caused by some strictly mechanical defects) would reduce/disable the traction at any speed.
  • Posted 23 Aug 2013 17:56
  • By Karait
  • joined 21 Jun'09 - 355 messages
  • Poland
Its very rare for a newer design Linde hydrostatic transmission to give any trouble, in the 5+ years I've been looking after a fleet of 392 & 394 Linde's we haven't had any issues with the hydrostatic transmission at all.

Only things that have actually failed so far on the fleet & caused a breakdown are:

Brake micro switch x 2
Coolant reservoirs x 3
Gas shut of valve x 1
Throttle pot x 3
Inner rear hub bearing x 1
Parking brake **** interlock spring x 2
Parking brake actuator lever x 1

Plus a loose starter motor cable connection.

The newer family of Linde IC counter balance's is the best you can get in Europe, there very well designed, there built to last & there easy to service / repair when needed.

It sounds like your local Linde dealer need's to invest in some training OR get someone else with experience to look at this truck.
If you don't know your way around Pathfinder you can really mess the truck settings up & causes all sorts of problems.
  • Posted 23 Aug 2013 07:24
  • By Forkingabout
  • joined 31 Mar'11 - 862 messages
  • england, United Kingdom
supposedly, Hes from the Local Linde Dealer (The Largest One in the US) He seemed uncomfortable operating the pathfinder software last time when he diagnosed the bad hydrostat. which we replaced and didnt solve our issue. He mentioned he felt like he needed more training
  • Posted 23 Aug 2013 04:34
  • Modified 23 Aug 2013 07:08 by poster
  • By Howitt
  • joined 13 Feb'09 - 80 messages
  • Ohio, United States
A replacement pot needs to be calibrated with Pathfinder.

Also its very easy to fit the pot incorrectly if you don't have experience at changing them, the little tab needs to be perfectly aligned when fitting - I've seen this happen before a couple of times when I've been called to look at a Linde.

Is this an official Linde trained engineer with Pathfinder coming back to look at it?
  • Posted 23 Aug 2013 03:59
  • By Forkingabout
  • joined 31 Mar'11 - 862 messages
  • england, United Kingdom
waiting on the dealer to show back up we replaced the pot , it didn't resolve the problem either
  • Posted 23 Aug 2013 03:43
  • By Howitt
  • joined 13 Feb'09 - 80 messages
  • Ohio, United States
I've replaced a few throttle pot's on Linde 392's, they never seem to throw an error but the poor performance of the throttle can normally be caught with Pathfinder by watching the voltage trace.

Last one I did the truck had lost top end traction performance, no errors showing but with Pathfinder you could see the pot was faulty, even recalibrating the pot didn't fix it.

New pot cured it.
  • Posted 23 Aug 2013 03:10
  • By Forkingabout
  • joined 31 Mar'11 - 862 messages
  • england, United Kingdom
How about the errors shown on Pathfinder (Linde Diagnostic Software) I understand, the disgnostics with the computer has been done by Linde service.

By the way, the fwd and rev selenoids are activated by the proper power not voltage.
You may check it with diagnostic software.
The wheels should start to rotate at circa 440/460 mA.
With the fully depressed acc pedal the value should be about 1220 mA.
The desired traction wheels speed should be ~ 200 rpm.

Generally, in my opinion, you may have problems with the traction pot. Even the calibration itself may not be enough. The pot may be anyway dead.Possible is the problem with the gear or pinion gear linked with the pot.

Still - it's all speculation. Yo can get the answers simply asking the dealer service (I understand it's Linde) for some serious computer diagnostics.
  • Posted 23 Aug 2013 01:25
  • Modified 23 Aug 2013 01:59 by poster
  • By Karait
  • joined 21 Jun'09 - 355 messages
  • Poland
I know your deepest secret fear...
J.M.
Max engine rpm is set to 2700RPM
Both Speed Sensors Has been replaced. the linde speed sensor looks to been defective or was going bad. The engine revs smooth and easier now but does not solve our issue. The VW engine speed sensor made no difference

There is no error codes shown on the display at all.
  • Posted 23 Aug 2013 01:22
  • By Howitt
  • joined 13 Feb'09 - 80 messages
  • Ohio, United States
Good remarks, duodeluxe

I'ld ask additionally if there are no error codes on display or in Pathfinder? I understand Linde dealer service connected the laptop to the truck? If there are issues with the traction electronics, the Pathfinder should identify them.
  • Posted 22 Aug 2013 22:36
  • By Karait
  • joined 21 Jun'09 - 355 messages
  • Poland
I know your deepest secret fear...
J.M.
I would stop replacing parts and check for simple things like the pedal stops.
Was the truck ordered with reduced travel speed?
What is the maximum engine RPM?
What is the serial # of the truck?
There are two engine speed sensors, one is Linde and the other is VW. Have you checked them?
  • Posted 22 Aug 2013 21:47
  • By duodeluxe
  • joined 11 Feb'05 - 923 messages
  • United States
duodeluxe

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