Clark GPS20MB:
Truck will not move, only one wheel moves when in air.

EDIT: Brake drum is stuck! Now, how to loosen it??????????

I recently purchased a Clark GPS20MB at auction.

335 Hours Showing, no idea if this is accurate. Mitsubishi 4G54 2.6, single speed, pneumatic tires.
Machine is clean but has been painted at least twice. In the description it was noted "This lift came from a local stove and pellet company. They said that sometimes it moves and operates for days then it will stop. Once it sits it works fine again."

I cannot get the machine to move, hydraulics all seem to work including steering. Checked Oil and Hydro fluid, both are at correct levels. This machine has dry automotive type brake drums and shoes with one master cylinder.

I jacked the front wheels off the ground and I can only get one wheel to move when I engage fwd or rev. I cracked brake bleeders, no change. The same wheel can be spun freely while in neutral, but the other wheel cannot. The bad side has about 1/4"-1/2" of easy play and then locks up hard, this makes me suspect a differential or something other than the brake. Basically the brake backing plate is fixed but the drum will move fwd and back just a small amount. I forgot to test to see if this same movement is present with brakes applied, I will do that tomorrow.

Does anyone have any ideas before I pull the hubs and shafts? Should I trans and look for metal first?
Could this be an inching valve issue, on just one wheel? I do not know how to bypass.

I have copies of both service and owners manuals that I found online.

THANKS!!!
  • Posted 22 Oct 2014 13:23
  • Modified 24 Oct 2014 12:18 by poster
  • Discussion started by Jordan
  • Maryland, United States
Showing items 1 - 15 of 17 results.
FIXED IT!!! Thank you guys!!!!

mrfixit's idea worked perfectly:
"Take the axle out, remove the retainer plate that holds the brake drum and hub on, remove the bearing, hit the outer edge of the wheel with a big hammer and try to get it rocking a little from side to side."

Now I need to go back and bleed the brakes since I am sure a let a little air in when cracking the bleeders.

Thanks Again!
  • Posted 3 Dec 2014 13:36
  • Reply by Jordan
  • Maryland, United States
Did you ever fix it?
  • Posted 2 Dec 2014 10:18
  • Reply by Topnotch
  • South Carolina, United States
This has 2 spinning star shaped adjusters, one for each shoe and there are holes in the bottom of backing plate to access them. The hole in the drum is big and you can see what you're doing much easier.
  • Posted 30 Oct 2014 05:27
  • Reply by mrfixit
  • New York, United States
no adjusting holes in the backing plate?
can't stick a thin flat blade screwdriver in and move the lock tab back and de-adjust it?

look close at the backing plate where the adjuster hole is supposed to be, it could be that it was never knocked out but is there. i run across these occasionally.

if you find this to be the case, knock it out, deadjust the wheel, pull the hub and remove the piece knocked out... then go from there.
  • Posted 29 Oct 2014 23:51
  • Modified 29 Oct 2014 23:59 by poster
  • Reply by swoop223
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com
If worse worse to worse and none of what has been mentioned works...do as mrfixit just posted then get a big prybar and start prying and heaving on the drum......sont worry about damaging the shooes as your going to be doing a complete brake job after you get the drum off anyways(i hope?) jam the prybar between the drum and edge of the backing plate might damage the backing plate some but this MAY be the only way to get the drum off...
  • Posted 29 Oct 2014 22:50
  • Reply by kevin_t
  • Pennsylvania, United States
Take the axle out, remove the retainer plate that holds the brake drum and hub on, remove the bearing, hit the outer edge of the wheel with a big hammer and try to get it rocking a little from side to side. That should start to get it loose. If the parking brake cable that goes in the back of the wheel is stuck and is pulling the brake shoes, cut it off so it releases the shoes. There is also a big hole in the brake drum to access the brake shoe adjusters but you would have to get the drum to rotate some to get the hole lined up to spin the adjusters loose.
  • Posted 29 Oct 2014 22:08
  • Reply by mrfixit
  • New York, United States
I am putting it in Fwd or Rev and then revving. Should I be dumping the clutch so to speak, with the machine wide open and then put in gear?
  • Posted 29 Oct 2014 13:48
  • Reply by Jordan
  • Maryland, United States
I tried your rocking method the other day and didn't really have any luck. Jacked on side and blocked the free spinning wheel so it would not move. I was taking the machine to wide open throttle, back and forth and the stuck wheel would not jar free.

Anything else I could try short of cutting? I was going to try and smack the drum around a little, then heat the outside of the hub and then try the this rocking thing again.
  • Posted 29 Oct 2014 13:14
  • Reply by Jordan
  • Maryland, United States
really, just like getting a car stuck in a pothole to climb out of the pothole by rocking it back and forth, this is your best bet.
you CAN try taking the wheel off, and pounding on the drum with a good sized sledge hammer a bit, you may get enough vibration where the shoe is stuck.
put both wheels on the floor and give it a go, maybe a pair of 2x4 in front and behind the good side, to keep the one good side from moving too easy...
you can also see part of the park brake cable in the handle to see if it is moving like expected.
heat would mean that you are going to replace the drum. so you might as well use the cutting torch as the rosebud.
  • Posted 28 Oct 2014 21:54
  • Reply by edward_t
  • South Carolina, United States
"it's not rocket surgery"
I am pretty sure the parking brake is inside the drum... Any idea's on how to beak this loose? Heat???
  • Posted 28 Oct 2014 11:32
  • Modified 28 Oct 2014 11:32 by poster
  • Reply by Jordan
  • Maryland, United States
Make sure the parking brake cable has not rusted and stuck on.
  • Posted 24 Oct 2014 20:57
  • Reply by mrfixit
  • New York, United States
Thanks soooo much for the info and ideas guys! I have confirmed that it's definitely the brake that is stuck!

I tried the chalking the loose wheel idea to no avail, WOT on the engine and the stuck wheel will not budge. Unbolted the axle and confirmed that is spins freely.

Any other ideas on how to break this thing free?
  • Posted 24 Oct 2014 12:25
  • Modified 24 Oct 2014 12:26 by poster
  • Reply by Jordan
  • Maryland, United States
you would loose about 1 to 2 cups of 90weight gear oil, and less if you have the wheel that you are removing higher than the other wheel. I stuff a rag in the axle hole to prevent much more oil from spilling while the axle is out.
Yes, I saw the part with; "1/4"-1/2" of easy play and then locks up hard". I expect this to be the shoes moving on the backing plate, twisting with the drum they are stuck onto, but only as far as they can before the hardware catches.
I work for a company that buys "off lease" trucks from other dealers, and we often see trucks that the shoes have stuck to the drum from rust after a few months sitting. they mostly move a little bit like you say.
  • Posted 23 Oct 2014 09:33
  • Reply by edward_t
  • South Carolina, United States
"it's not rocket surgery"
That's an idea... Know how much, if any fluid I would lose?
  • Posted 23 Oct 2014 08:20
  • Reply by Jordan
  • Maryland, United States
You could unbolt the axle from the wheel/hub and see if the wheel, hub, and brake drum spins then. If so, then the differential is where the problem is.
  • Posted 23 Oct 2014 08:04
  • Reply by mrfixit
  • New York, United States

Post your Reply

Forkliftaction.com accepts no responsibility for forum content and requires forum participants to adhere to the rules. Click here for more information.

Having trouble using the Discussion Forums? Contact us for help.

Global Industry News
edition #1200 - 10 October 2024
Today is World Mental Health Day, dedicated to raising awareness of mental health issues around the world... Continue reading

PREMIUM business

VETTER Industrie GmbH
The world's most comprehensive range of forks and the most intelligent sensor fork for more safety and efficiency.
Upcoming in the editorial calendar
FORKLIFT DAMAGE PREVENTION
Nov 2024
AGV FORKLIFT MANUFACTURERS
Feb 2025