743b restoration

[cumminsguy]

You guys have helped me out in the past yr. re-pairing my old 743b, i would like to show you all how she looks now but cant seem to pull the pics off my desk top and drop them in the message box. any help would be great. Thanks, Tom

 

[OldMachinist]

Pictures have to be hosted on the internet somewhere or they won't show up here. Any of the free image hosting sites(Photobucket, Flickr, Imageshack, etc. etc.) will work.

 

[SkidRoe]

Have a read of this:
http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=2445
HTH - SR

 

[cumminsguy]

Have a read of this:
http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=2445
HTH - SR

Thanks Guys, I have started posting the restoration pics under ( cumminsguy 743b ) in the pictures area here on the site, take a look I will continue with the latest finished pictures shortly. Thanks again for all the help. Tom

 

[cumminsguy]

Thanks Guys, I have started posting the restoration pics under ( cumminsguy 743b ) in the pictures area here on the site, take a look I will continue with the latest finished pictures shortly. Thanks again for all the help. Tom

Its on page 2, sorry some have come out sideways.

 

[SkidRoe]

Its on page 2, sorry some have come out sideways.

Good looking machine, well done!! I have always had a soft spot for 743's.

 

[cumminsguy]

Good looking machine, well done!! I have always had a soft spot for 743's.

I have posted a pic of the front hydro gear pump and was wondering if anyone has ever attempted to do a rebuild on one of these. The pic is in the file with my restoration pics. My tilt will fade and my bucket will begin to dump after about 5 or so minutes so I'm thinking its most likely seals in this pump?

 

[cumminsguy]

I have posted a pic of the front hydro gear pump and was wondering if anyone has ever attempted to do a rebuild on one of these. The pic is in the file with my restoration pics. My tilt will fade and my bucket will begin to dump after about 5 or so minutes so I'm thinking its most likely seals in this pump?

Thanks for the kind words SkidRoe, Its been a fun project, kinda hard trying to rebuild/refinish this machine and still use it for work at the same time but its come along way, afew more things here and there and I might be able to say its finished.

 

[cumminsguy]

Thanks for the kind words SkidRoe, Its been a fun project, kinda hard trying to rebuild/refinish this machine and still use it for work at the same time but its come along way, afew more things here and there and I might be able to say its finished.

http://www.skidsteerforum.com/Portals/57ad7180-c5e7-49f5-b282-c6475cdb7ee7/TTTGallery/cumminsguy%20743b/_thumbs/IMG_0541.jpg

 

[SkidRoe]

I have posted a pic of the front hydro gear pump and was wondering if anyone has ever attempted to do a rebuild on one of these. The pic is in the file with my restoration pics. My tilt will fade and my bucket will begin to dump after about 5 or so minutes so I'm thinking its most likely seals in this pump?

It is not the pump, it is worn piston seals. Best start by rebuilding the tilt cylinder, that will likely take care of your problem.
SR

 

[cumminsguy]

It is not the pump, it is worn piston seals. Best start by rebuilding the tilt cylinder, that will likely take care of your problem.
SR

I did rebuild the tilt cylinder and the lift arm cylinders, I'll cap the return line on the tilt cylinder and plug the hose and to see if it bleeds down, if it does then ill pull the cylinder back apart, if it doesn't would you tend to think its the pump then?

 

[OldMachinist]

I did rebuild the tilt cylinder and the lift arm cylinders, I'll cap the return line on the tilt cylinder and plug the hose and to see if it bleeds down, if it does then ill pull the cylinder back apart, if it doesn't would you tend to think its the pump then?

You said

“My tilt will fade and my bucket will begin to dump after about 5 or so minutes so I'm thinking its most likely seals in this pump?“ If its doing this without touching the pedals and you're sure the cylinder piston seals are good then I'd suspect the load check in the control valve.

 

[cumminsguy]

You said



“My tilt will fade and my bucket will begin to dump after about 5 or so minutes so I'm thinking its most likely seals in this pump?“
If its doing this without touching the pedals and you're sure the cylinder piston seals are good then I'd suspect the load check in the control valve.

Ok, so I will check the tilt piston for leak down first and go from there. thank you , I will post my findings.

 

[SkidRoe]

I did rebuild the tilt cylinder and the lift arm cylinders, I'll cap the return line on the tilt cylinder and plug the hose and to see if it bleeds down, if it does then ill pull the cylinder back apart, if it doesn't would you tend to think its the pump then?

Just to be totally clear, the pump plays no role in holding the bucket/boom in position:; that is all up to the cylinders and the control valve.
Excessive internal leakage in either of these will cause the cylinder(s) to drift at unacceptable rates.
Hope this helps - SR

 

[jerry]

Just to be totally clear, the pump plays no role in holding the bucket/boom in position:; that is all up to the cylinders and the control valve.
Excessive internal leakage in either of these will cause the cylinder(s) to drift at unacceptable rates.
Hope this helps - SR

Quite often on these forums you will see that a person thinks bad seals will mean external leaks and drips. If it is piston seal that is shot there will be no external sign of it, just oil bypassing the piston internally causing drift and reduced lift.

 

[cumminsguy]

Quite often on these forums you will see that a person thinks bad seals will mean external leaks and drips. If it is piston seal that is shot there will be no external sign of it, just oil bypassing the piston internally causing drift and reduced lift.

Yes I understand that, it will most likely be the control valve, the tilt and lift cylinders are completely re-built and no scoring at all to the piston shaft. I played around with the loader today and brought the lift arms all the way up and tilted the bucket all the way back and turned off the machine, after 20 or so minutes the arms dropped 5" and the bucket started tipping too ( had not noticed the arms dropping before). So without the pump running the system is bleeding down slowly, the machine is still very much useable but little things like this tend to bother me till its fixed. I saw another post here about someone else working on there control valve so I'll follow along his post and dive into mine in the near future. Thanks again for all the help here from every one.

 

[Tazza]

Yes I understand that, it will most likely be the control valve, the tilt and lift cylinders are completely re-built and no scoring at all to the piston shaft. I played around with the loader today and brought the lift arms all the way up and tilted the bucket all the way back and turned off the machine, after 20 or so minutes the arms dropped 5" and the bucket started tipping too ( had not noticed the arms dropping before). So without the pump running the system is bleeding down slowly, the machine is still very much useable but little things like this tend to bother me till its fixed. I saw another post here about someone else working on there control valve so I'll follow along his post and dive into mine in the near future. Thanks again for all the help here from every one.

The control block has load checks, they may need new seals. If the seats are worn, there isn't a whole lot you can do to fix it.
That is only a small leak down, if you can live with it, so so. I know what you mean about them bugging you that it is not right.

 

[cumminsguy]

The control block has load checks, they may need new seals. If the seats are worn, there isn't a whole lot you can do to fix it.
That is only a small leak down, if you can live with it, so so. I know what you mean about them bugging you that it is not right.

I won't mess with it right now, would like to make some more $$$ with it first.