15w60 full synth in Hydro Gear PG pumps & motors

Status
Not open for further replies.
Joined
Jul 7, 2016
Messages
1
Location
New South Wales, Australia
my gravely compact pro 34 has hydro gear 10cc pumps & motors. Its due for its 1st oil change - I have some 15w60 full synthetic (Penrite HPR15) and wonder if it would be safe to use? It would currently have 20w50 dinosaur oil in it and I would be draining from the filter so it won't be a 100% removal....is it ok for synth & dino to be mixed?
 
The dino syth mix doesn't matter and hasn't been an issue since the 70's. It probably wouldn't matter, but why not just use either 15w50 or 20w50 like recommended? I'm not sure how cold it gets in Australia, probably not very, but I know on my gravely it takes a few minutes for the hydros to warm up and loosen up so to speak. It's hard for me to explain.
 
Hydro Gear has a min. viscosity but not a maximum. So yes, it should work. If its what I think it is, most of fluid do drain out.
 
Why not use an ISO 68 hydraulic fluid? It would perform better in this application. Engine oil is only specified because it is easier to obtain.
 
Last edited:
Originally Posted By: DriveHard
Why not use an ISO 68 hydraulic fluid? It would perform better in this application. Engine oil is only specified because it is easier to obtain.


Says not to use hydraulic fluid, but is this because people might use the wrong kind? Looks like their is three different thicknesses, iso68 being the thickest.
 
Originally Posted By: Jetronic
I suppose you need hydraulic fluid with zinc, ashless exists aswell but if the system required that they wouldn't recommend engine oil.


There is a guy on youtube that repairs these. He said the guy brought the mower in and used hydraulic fluid. The machine wouldn't even move forward hardly. Maybe he used the wrong grade of hydraulic fluid?
 
Last edited by a moderator:
The only reason I can think of that the machine won't move, is because the pump is worn and can't pressurise properly with thinner oil. I'd also look into stick/slip action when lightly loaded, riction modiiers might be needed?

You're using 20w50 now, why change?
 
I use mobil 1 15w50. Says you can use either. Just wondering why a hydraulic system calls for motor oil, why not use hydraulic fluid like normal.

Or is a hydro gear pump and wheel motor not a true hydraulic system?
 
Originally Posted By: motor_oil_madman
Originally Posted By: DriveHard
Why not use an ISO 68 hydraulic fluid? It would perform better in this application. Engine oil is only specified because it is easier to obtain.


Says not to use hydraulic fluid, but is this because people might use the wrong kind? Looks like their is three different thicknesses, iso68 being the thickest.


Yup, they specify engine oil because it is easy to get, and there is a higher chance people will choose the correct viscosity. I will say that an SAE crankcase oil of weight 50 is a THICK hydraulic fluid and might be hard to find...I think it is equal to an ISO 150 or 220 grade hydraulic fluid. If it was my machine I would be running the ISO 220 hydraulic fluid.

UNLESS you run it in the winter...then you might want to stick with the multi-grade oil.
 
Status
Not open for further replies.
Back
Top