Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

Sign in to follow this  

Sunstar hydro pump helpful with Sovereign PS install?

Recommended Posts


I have been searching and reading a lot lately on adding power steering to my 917 and a Sovereign roller chassis I have.  Some articles date back to 2007.  It seems there is an uncertainty regarding why the Sovereign PS lags compared to the Sunstar.  

Has anybody figured out why?  Is it because the Sunstars Hydro Sundstrand pump is better suited for PS and hydraulic lift than the current Sovereign Sundstrands??? 

I have a Deutz 1920H with a junk motor and wondered if taking the Sunstrand pump out of it and putting it into my Sovereign would solve the lag issue many others have discussed or if the pump will even bolt up nice...

Edited by Alltractoredup

Share this post

Link to post
Share on other sites

The Sunstar Sundstrand Series 15 pump is a different spec # than the Sovereign Series 15 pump.  The biggest difference that I know of is that the Sunstar pump has a mainshaft that is splined on both ends to drive the rear PTO.  This means that swapping the Sovereign pump with a Sunstar pump is not so simple. There may be other internal differences and the pressure relief valve settings may differ (probably).  It appears that all Sunstar pumps have the higher volume charge pump, not all Sovereign pumps do.  There are at least 7 different spec #'s for Sovereign pumps,  but only one that I know of for the Sunstars.  I have not compared the hydraulic circuits between the two systems to understand if the hydraulic priorities are different (is steering a higher priority on the Sunstar?)  Inquiring minds want to know.  

Edited by CarlH
  • Thanks 1

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Who's Online (See full list)

    There are no registered users currently online

  • Today's Birthdays

    No users celebrating today
  • Recent Status Updates

    • Paul M.Murphy

      Paul M.Murphy

      Hello glad I got on this site. I hope to upload a couple of photos of my Simplicity Broadmoor 
      Model 707 Tractor. I have replaced all the belts on it and installed a new ignition switch.
      Have a mower deck which was in poor shape , repaced a couple of bushings and welded the
      deck where there was some holes. The tractor and mower deck came from a friend and the 
      mower deck metal was getting pretty thin. Some new metal was put in it and we also undercoated the underside of the deck. This was done by my friend Greg Toulman.
      I have not put the mower deck on the tractor yet, waiting for Greg to come home and give me a hand. Can you please tell me if there is a manual for the mower deck and where I could get one.
      I would also like to get some moon wheel discs as well.
      I will try and down load some photos of the tractor when my wife shows me how to. 
      I really love driving this tractor and also how well it is made compare today's tractors, especially the flexible rear end and the rollers.
      Tell the next time 
      · 8 replies
    • jbrooks

      jbrooks  »  Talntedmrgreen

      folowing  this from a link at the downloads.  I just rescued an AC 920 with the lambodini diesel. I can' t download  yet .  Where did you find the PDF copy you posted. . I would like to figure out how to adjust the injection pump. 
      I assume it's a bosche, correct
      · 0 replies
  • Adverts