Hydraulic pressure testing for hydrostatic transmissions

[BMW1 42]

What brand of gauge and/or setup are people using to test the pressure in their hydrostatic transmissions?

 

The wheel horse hydrostatic manual says to use a 0-1000 psi gauge. The gauge in the picture in the manual(page 25 in Sunstrand Hydro (part 1).pdf) only goes to 600psi - which is probably fine as long as it's not used to test the cylinders.

 

I found several test gauges, but most are 0-3000 or more.  I found a couple that were 0-1000 but the increment lines on the gauge are around 50-60, which means the gauge would move only a small amount.  The manual says the pressure should be between 75 and 150 psi. 

Most of the reasonably priced digital gauges I saw had bad reviews.  

 

 

[wallfish 16,994]

Never used one to test transmissions but you can find many different gauges here. Some have increments of 20 psi

Not 100% sure but think the max pressure at the cylinder should be around 700-750 psi..

https://www.surpluscenter.com/Hydraulics/Hydraulic-Gauges/Pressure-Vacuum-Gauges/?page_no=1

 

[JCM 9,130]

Looking through some old notes I have regarding testing the Eaton 1100 Trans back in 2001 that was on a 1993 520-H I sold, normal charge pressure should be 30-90 PSI and implement lift pressure should be 700 + or - 50 PSI . My pressures were 200 charge and 810 lift. I was told to purchase a fluid filled guage to check these pressures and report back to the repair shop. when i did I was told to ship the pump out for repairs. I put no blame on WH or Eaton for the issues with the 1100, I believe it was the PO . When I removed the Transaxle and pump I found remnants of orange looking Permatex Gasket maker on the Trans case and thinking some of that may have caused the high pressures.There was also a rubber Hydraulic hose Micky Moused on the Pump that I changed to the correct WH line. I do still have that guage and will have to move some tractors to get at it and check the range and increments. I think I also have the old WH filter that was on the 1100 when the problem started and it looked like a beer can that was left out in freezing weather, the top of the can was pushed upwards at the top at the gasket side and allowed the oil to be forced out, not a good situation. The Pump was resealed and tested and after it was shipped back I installed it and ran that tractor until I sold it to a friend in 2005 and there have been no issues with it since the repairs.I did set the pressures to 60 PSI charge and 750 PSI lift.

[pfrederi 17,725]

I bought a couple different gauges from surplus center.  You want the desired test pressure to fall in the mid range of the gauge.  One for charge pump test and one for implement test.  As= far as baf=d reviews you would never buy anything anymore there is a bad review for everything.

[JCM 9,130]

@BMW1     I did locate that guage it is a 2- 3/4'' face with a 2-1/2'' body,1/4'' NPT    0-1000  PSI  in 20 lb increments , Stainless Steel fluid filled  by  NOSHOK  Made in Germany  FYI  this is a very high quality Guage by looking at it.

[BMW1 42]

Thanks for the replies.  

JCM - Appreciate you getting the information.  I will see if I can find one like that.