The Forestry Forum

General Forestry => Sawmills and Milling => Topic started by: Stephen1 on August 04, 2013, 09:32:21 AM

Title: Help, Replace hydraulic return springs
Post by: Stephen1 on August 04, 2013, 09:32:21 AM
I broke a return spring on the handles for hydraulics. I have a lt40hd g24 1993. I was able to replace one of the four, on the end closest to the mill. It seems like I will have to pull every switch off to replace the rest. I was also sent 4 contact springs which I dont know where they are in these switches.
Has anyone done thesee?
Title: Re: Help, Replace hydraulic return springs
Post by: POSTON WIDEHEAD on August 04, 2013, 09:35:02 AM
Stephen, I have never had to replace mine YET. But just asking, does it show it in the manuel?
I'll look when I get home and check my manuel.
Title: Re: Help, Replace hydraulic return springs
Post by: Stephen1 on August 04, 2013, 09:57:36 AM
I found it in my manual.Just the schematics, so I know where the contact spring belongs and how to get to it.
New Question, will I have to pull thes valves off? If so,  which I think I do,
What am I looking out for? I know to disconnect the battery, will they be under pressure when I discinnect the fittings?
Title: Re: Help, Replace hydraulic return springs
Post by: rmack on August 04, 2013, 10:02:44 AM
ElectricAl has a video on this.

http://www.youtube.com/watch?v=yQcXrP8ehTE
Title: Re: Help, Replace hydraulic return springs
Post by: Stephen1 on August 04, 2013, 11:24:21 AM
Great, that works fo me.
Thanks rmack, and Al for making the video. 8)
Title: Re: Help, Replace hydraulic return springs
Post by: Jim_Rogers on August 04, 2013, 03:57:34 PM
Stephen:
There is a whole thread about replacing those springs here somewhere. I posted some pictures of doing it as well.
the thing you need to be careful of is that the handle gets put back on the valve shaft correctly or the valve will be open one way when you back up the carriage and the hydraulics will turn on by themselves.



 (https://forestryforum.com/gallery/albums/userpics/10095/DSCF0140.JPG)

 

 (https://forestryforum.com/gallery/albums/userpics/10095/DSCF0142.JPG)

 

 (https://forestryforum.com/gallery/albums/userpics/10095/DSCF0143.JPG)

 

 (https://forestryforum.com/gallery/albums/userpics/10095/DSCF0129.JPG)

The last picture shows the handle down as the spring was broken.
To remove the valve you can just undo the connection below the valve and lift it up a short ways, due to the wire. Then you can hold it in your hand and work on it.
I scratched a line across the end of the shaft to align the handle with the shaft.
Then you dig out the set screw with an ice pick and clean out any sawdust. Then turn the set screw out. This will allow you to slide the handle off and watch out you don't drop all your washers and spacers. Then slide the new spring on and make sure it's aligned like in my picture above. Then slide the handle with washers and spacer back on so that the roll pin on the handle goes between the spring ends below the roll pin on the valve body.

If you take the valve unit out, you can change the contact spring at the same time. There are two screws holding a plastic cap on the back to open up and see the contact spring. I don't have a picture of that, that I can remember. But you can see it and if you have a new one you can easily replace it in the same position that the old one was in. If the old one is broken then you may have to look at another valve unit to see how it goes. I did it and if I can do you you can do it. It's not that hard, once you've done it, you won't have any problems doing it again.
If you have any questions about it, just post back or call me.

Jim Rogers
Title: Re: Help, Replace hydraulic return springs
Post by: sawmillhand on August 05, 2013, 04:36:47 AM
Nice pics Jim. The one thing i did do before i unhooked anything was clean around it get as much saw dust away from any openings. Sure don't want that trash in your hyd system.
Title: Re: Help, Replace hydraulic return springs
Post by: Stephen1 on August 05, 2013, 07:38:38 AM
Thanks guys, that job is done. replaced all the springs. Kept 2 unbroken ones for spares.