I know im kinda off topic but I recently purchased a C500
Ship date: May 1975
Model#CHY160D
Serial#HY1625-14-3061
It ran great when I got it a week ago, with no problems from the hydraulics. the guy I bought it from said it needed some hydraulic fluid added to it because the steering ram leaked a bit. When I went to fill it the only place i found to fill it was from the dual filter units under the seat behind the side plate. When I removed the cover from the front filter tube, I heard a ?suucking? sound. After putting 15gal into the tank and sealing the filter unit back up, the hydraulics felt like they were full of air (jittering, loud groans from the pump, settling of the forks 8"-12" after stopping vertical lift) I noticed later that the main Hyd. pump is fed from the top of the tank from the filter tubes. which means the hyd. fluid has to come up from the tank through the filters and into the feed tube. Im assuming that I bleed off the pressure/vaccum that was present in the filter tubes, causing the air problem.

My question is: Is there a specific way to "pressurize the system" after changing the filters and adding fluids, and if any one knows where i can find a service manual for this particular Forklift?

I checked the Clark dealer locations and called the dealer in Milwaukee, Or. They said the service manual was no longer available but the operators manual was, along with the parts manual. They were also unfamiliar with a Hyd. system that old. The guy I spoke to said he would try and see if he could locate their copy of the service manual and have it copied for us but I'm not holding my breath.

Would the operators manual have anything on this issue in it?

Any help is appreciated.

Will

*Edit* had to change spelling of S., U, C. K. Ing due to Censoring LOL