Guys, I need some help. I built a tunnel tab with a pair of trim tabs and a plate. I am using an Oildyne pump that made so much pressure it blew off one of the cylinders and ruined the threads. Rounded them and they are now worthless. I am making new covers for the cylinders that are a lot beefier with thicker walls and deeper threads.
My problem still remains too much pressure from the pump. On my drive pumps, the sound changes when the drives are all the way in or out and I assume there is a pressure releif valve built into them that is not in the Oildyne pumps.

How do I add a pressure relief valve to this pump. I hope this picture works.


thanks
Shawn

There's a relief in that pump.
Just need weaker spring in it (or shorter spring).

here is the pressure relief valve. The pressure range should be 2200-2600 on the "up" side. You may be able to ignore the warning and adjust the relief valve.

A picture is worth 10 words, ok maybe more.

Adjust it till you haver the pressure you need. Remember when the blue wire is hot the high pressure side is pressurized. Clip the spring if yo have to, but just try backing it off. We use these for hatch lifts, and if you don't lower the pressure and have a party going on back on your hatch it will either dump everybody overboard or break something. It helps to hook a gauge up to it, should be 3000 PSI max range. We only run 600 PSI or so for the hatches.

Ok I guess we are talking about the valves inside the pump. What are the large hex nuts on either side of the pump for?. I know they have a spring and ball under them.
What direction does one adjust the valves to increase the pressure?

Side ports are check valves. One is up and one is down.

The competition-tab/outboard pump you have in the picture is set to over 3400psi on the high pressure output side (UP) and about 1800psi on the low pressure output side (DN). If you order the replacement relief valves (as shown in the pictures above), I think they are set to the Bravo relief pressures by default, 2000+ on the UP side, 400-600psi on the DN side. The standard tab pumps that come with K-Planes are about 1600-1800psi on the UP, 600-800psi DN. Keep in mind that these pressures are from memory (not always good), but the exact pressure settings are not that important, just pointing out that you could set the pump down closer to the K-Plane settings or maybe even slightly lower. Keep in mind that these pumps were all originally designed for outboards and sterndrives, not tabs. The pump body markings are backwards from the line hookups. You have the higher pressure output port from the pump (UP) hooked to the line that pushes the cylinder out and the tab will go down.
Did you purchase these pumps new? I would think that a tab pump (or Bravo pump) would be cheaper.

Ok I am having the opposite problem that shawn is having. My tunnel tap keeps pushing back up. So can I increase the pressure on the check valves to stop this?

Shawn Who makes the rams and can you find the working pressure of them.

mmwalters no your problem would be leak down in some outher form.Maybe the thermal relief.Maybe shuttles.