Hydraulic purging for a 15 year old Gravely Promaster 44Z

[satman858]

Hi everyone,

I just changed out a Hydraulic hose line that leaked out to the point of losing power, and now I am about to add some Mobile One 15W50 Synthetic motor oil as recommended in my manual. Since I am not doing a complete oil filter change, because it was changed last year, that knowing how much oil the manual says it takes will not help me in my case. I know how to purge the unit by way of the two bolts on the the two pumps, but I have a question about how to determine what is to little oil or to much oil by way of the dipstick reading, that these old Zero Turns lawnmowers used back then.

My question is this:

Should I measure the oil in the Hydraulic tank by screwing the dipstick all the way in, or by unscrewing the dipstick and measure it by dipping it in unscrewed?

As seen in the photo below circled in "Blue" you can see that there is a good 1 inch difference in the reading screwed in or not screwed in.

 

[StarTech]

The way I read the following from the owners manual you read it after has been screwed and then removed.

 

[satman858]

The way I read the following from the owners manual you read it after has been screwed and then removed.
View attachment 57976

These instructions in the manual are completely inaccurate, and full of mistakes.

1,) The engine has just been running for 10 minutes, and it tells you to stop the engine and unscrew the dipstick and check the dipstick for the Hydraulic oil level. (Doing this just after the engine hot will give you a false reading as the engine oil MUST cool down before checking, which is in all oil checking cases)

2.) It also does not address the complete purge instructions to get the air out of the system, which requires cycling the levers forward and back with the bolts on each pump opened a 1/2 turn, to allow the air to be pushed out the system, then tightening those bolts up and repeating the cycling of the levers forward and back once again before checking the reading on the dipstick.

3.) Last but certainly not least, is addressing my issue of the reapplying of the dipstick after wiping the oil off, and then giving you instructions into if it is to be screwed in to check it, or be checked outside of it being screwed in.
(I understand where you are getting your thinking about it being done screwed in to check it, but as we all know, to check any oil, you should wipe the oil off and reapply after removing the dipstick to get an accurate reading.)

Thank you for your reply, but I still think I need to get all of the complete information from that addresses all the issues I brought forth above, before going forward with doing this correctly.