hidraulic prerotator help

[Caribean_gyro]

my pre rotator stop working. when I send it to a shop they told me 1 of the 2 pump was bad. so I bought a new pump and 2 repair kit. Today I install it and found I mounted the clutch pump inverted so in the reserviour line I was getting high preasure and forcing oil out.

I swamp lines and now I se when the pump is ingage the oil us pull down but when the whole sistem is purge of air I get back firing on the low preasure line and the upper pump dont turn? they are gresen pump ports are identified as port a or port B. They are bidirectional.

Tomorrow I am taking the uper pum appart put a repair kit and take the bendix out. I have oil all over the gyro and the hangar.

any suggestion or inputs I really need it.
Chuck Peterson

[Doug Riley]

Chuck: Are you sure you have bled out all the air? Try turning the lower pump by hand (in the correct direction!). Watch for the oil level to go down in the tank, and keep refilling it before it empties -- this eventually fills the circuit. Bubbles will come through the system to the tank. Keep turning by hand and topping up the tank until the level no longer goes down.

You can run the system either pressurized or unpressurized. If pressurized, the tank must be strong enough to withstand the pressure and the fill cap must be unvented and sealed. Ernie Boyette claims that a pressurized system yields more RRPM. I tried pressurizing and it did seem to get better RRPM, but my tank cracked and leaked almost immediately. I went back to a vented cap.

[Caribean_gyro]

finally it turn. I put the repair kit fill it and turn it by hand at the same time I actuate the system. the problem now is that the bendix stay engage. I have to adjust now the pump mounting. Now I was using transmition oil now I have real hydraulic oil.

Findings is that after 2 years the lower pump was ruin

chuckP

thanks doug

[Doug Riley]

Did the transmission oil ruin it?

[jos]

Ones a closed hydraulic circuit has one of the components damaged the debris left wil ruin the next component and so on .
Major cleaning is the first step to a solution.
Do not replace any part before cleaning unless you have a very powerfull filter.
JOS

[jdalexa]

Is it plain ol' transmission oil in Ernies hydraulic pre-rotators on the Dominator? I've been wondering as the color is wrong for hydraulic oil

[Caribean_gyro]

I use trans oil for 200 hours in mine. never a problem. Until it didnt work. I was wondering about the sediments when I flush the system and fould my lower clutch pump worn out. scuffing marks in it. So I have to buy a new one.

Sistem is working but last night I found a leak on the new pump. Since I have to chage the shaft to accept my cluth it seems I pinch the oil ring.

I dont know why the ring is a bit bigger then the grove it mount. I have a repair kit and replace the oilring last night. WIll know tomorrow if I finally solve it.

I am using hydraulic oil use on auto jacks. It has a higher viscosity.
Chuck :)