How to ADD Hydraulic Fluid

[Kluffinator]

I use a small hand pump I got at harbor freight for under 9 bucks. I only use it for transmission fluid so it was equally handy for the transmission or filling the jack reservoir

[GKU]

After checking the fluid level in the tank properly. (Jacks Up -- Slide Out). I added 2 quarts of ATF.



The coach is garaged at our house in an attached garage with concrete floors, I found no leak.


This was another great learning experience with spot on help from members of this forum....Thanks!!!

[Old Scout]

...all is well that ends well...am still of the "opinion" that only uni-directional rams [eg jacks] have an impact on fluid levels.....hard to see how bi-directional slide cylinders being open or closed, would have an impact.....just an old farm kid's opinion....

[GKU]

Old Scout your "Opinion" might be correct. As I went through ALL options of Jacks up/down slide in/out the only one that made a difference as to the fluid level in the tank were the Jacks!!



The Jacks MUST be up when checking fluid level in the tank.

[twinboat]

Originally Posted by Old Scout

...all is well that ends well...am still of the "opinion" that only uni-directional rams [eg jacks] have an impact on fluid levels.....hard to see how bi-directional slide cylinders being open or closed, would have an impact.....just an old farm kid's opinion....

A retracted, double acting cylinder will hold less oil, because the piston rod is in the same side, displacing the oil.

A double acting cylinder will have more power pushing, then pulling, for the same reason.

[Old Scout]

TB--excellent point...never considered the displacement volume of the slide ram rods in the equation...guess you are also saying the dia. of the rod also has to be subtracted from the lbs/sq inch pressure equation for retracting too... extended/retracted rod position for a typical slide mechanism is pretty obvious, may be not so obvious for a scissor mechanism?
Sorry, not very technical here but what happens on the retract side of a leveling jack ram? Realize the springs retract the piston and fluid is pushed/returns to the reservoir, and piston/ram dia. is very close to the cylinder inside dia, but it seems like there would be a vacuum or displacement issue between the ram o-ring seal and lower scraper seal?

[twinboat]

Originally Posted by Old Scout

TB--excellent point...never considered the displacement volume of the slide ram rods in the equation...guess you are also saying the dia. of the rod also has to be subtracted from the lbs/sq inch pressure equation for retracting too... extended/retracted rod position for a typical slide mechanism is pretty obvious, may be not so obvious for a scissor mechanism?
Sorry, not very technical here but what happens on the retract side of a leveling jack ram? Realize the springs retract the piston and fluid is pushed/returns to the reservoir, and piston/ram dia. is very close to the cylinder inside dia, but it seems like there would be a vacuum or displacement issue between the ram o-ring seal and lower scraper seal?

Single action cylinders don't have seals on the moving piston, only a guide bushing.

The oil seal in just inside the wiper. The oil fills against that seal and pushes the piston out of the cylinder.

If a double acting cylinder is used in a single acting position, the other port has a filterd vent in it.

[Boilervol]

Originally Posted by GKU

After checking the fluid level in the tank properly. (Jacks Up -- Slide Out). I added 2 quarts of ATF.



The coach is garaged at our house in an attached garage with concrete floors, I found no leak.


This was another great learning experience with spot on help from members of this forum....Thanks!!!

I remember when we took delivery there were several low fluid levels - hydraulic and coolant I remember for sure. You would think Newmar would include this in a quality check! We now have 19,000 on our 2019 and I’ve not added any addition fluids.