Last Mohecian
Administrator
I'm working on rebuilding my hydraulic trim for the YJ. I'm going to do my best to explain my concern & how this thing works since I'm pretty sure very few, if any, of you have ever seen one.
There is a ram that mounts on top of the pump that moves back and forth to trim the nozzle up & down. Fluid is pushed in one end to go up and the other end to go down. It is basically 2 single action cylinders, one on each end, using a common ram. You can see the pin that fits into the nozzle hanging out of the bottom of the ram in this picture:
The ram seals in the cylinders at the ends. You can see the seals installed on the ram here:
The cylinder walls look great on both ends. The pump works just fine. Everything is in good shape except for a little corrosion on the ram. This corrosion is what I am concerned about. The ram measures 1.245 at the non corroded part and 1.239 at the corroded part.
There is a wiper seal at the end of each cylinder. This is what rides on the corroded part of the ram. My guess is this wiper was intended to keep water out of the cylinder when the hydraulic seal is at the far end of travel. I see no way this seal will be 100% effective just given the physics of it. When the ram moves a vacuum is going to exist behind the seal and water is going to be sucked in to the small void between the ram and the cylinder wall. You can see the wiper seal here. This is the best I could do to get a picture of it. There is one for each cylinder toward the center of the piece. This pic is through the center hole where the pin was before I removed it for the rebuild.
I have a couple of solutions in mind:
(1) Have someone cut the ram down on a lathe even with the corrode part. Then I can have it (A) powder coated (B) ceramic coated to build it back up to close to the original diameter.
(2) Leave it the way it is and paint it with epoxy paint to prevent further corrosion.
(3) I'm way over thinking this and I should just leave it the way it is and put it back together without any effort to prevent further corrosion.
My guess is the real problem is when the cylinders get corroded. This is where the hydraulic seal happens. I'm thinking the best protection for the cylinder walls will be to run the ram back and forth a couple of times after each trip to the lake to displace any water and coat the cylinders with hydraulic fluid.
Any thoughts???????
There is a ram that mounts on top of the pump that moves back and forth to trim the nozzle up & down. Fluid is pushed in one end to go up and the other end to go down. It is basically 2 single action cylinders, one on each end, using a common ram. You can see the pin that fits into the nozzle hanging out of the bottom of the ram in this picture:
The ram seals in the cylinders at the ends. You can see the seals installed on the ram here:
The cylinder walls look great on both ends. The pump works just fine. Everything is in good shape except for a little corrosion on the ram. This corrosion is what I am concerned about. The ram measures 1.245 at the non corroded part and 1.239 at the corroded part.
There is a wiper seal at the end of each cylinder. This is what rides on the corroded part of the ram. My guess is this wiper was intended to keep water out of the cylinder when the hydraulic seal is at the far end of travel. I see no way this seal will be 100% effective just given the physics of it. When the ram moves a vacuum is going to exist behind the seal and water is going to be sucked in to the small void between the ram and the cylinder wall. You can see the wiper seal here. This is the best I could do to get a picture of it. There is one for each cylinder toward the center of the piece. This pic is through the center hole where the pin was before I removed it for the rebuild.
I have a couple of solutions in mind:
(1) Have someone cut the ram down on a lathe even with the corrode part. Then I can have it (A) powder coated (B) ceramic coated to build it back up to close to the original diameter.
(2) Leave it the way it is and paint it with epoxy paint to prevent further corrosion.
(3) I'm way over thinking this and I should just leave it the way it is and put it back together without any effort to prevent further corrosion.
My guess is the real problem is when the cylinders get corroded. This is where the hydraulic seal happens. I'm thinking the best protection for the cylinder walls will be to run the ram back and forth a couple of times after each trip to the lake to displace any water and coat the cylinders with hydraulic fluid.
Any thoughts???????
