Pesco 1P-677 Hydraulic Pump

[Rob58]

Really hate to bring this topic up again, but I am trying to resolve some confusion in my mind. In one of my machines, 08R, I have a Pesco 1P-677 CCW, so for a while I simply assumed that this was the correct part number (CCW = counter-clockwise). Now in 35R which is receiving a big dose of TLC at the present time I happened to look at the data plate and it says 1P-677 (no CCW), and I should note the hydraulic system works great. So this leads me to ask the questions: does it really matter which way the pump turns? Is the -CCW stamped on the dataplate just random and maybe the pumps are all the same inside? I am hoping someone out there has actually seen the inside of this pump so that I am not compelled to tear one apart. My knowledge of pump design, although limited, does suggest that some designs can spin either way. I also checked the type certificate and it lists the Pesco 1P-677, without the CCW. I wish things like this didn't bother me... I am just cursed with the need to know... Rob

 

[bbarrett]

I can’t explain the stamping. But I know for a fact that there’s a right and wrong way, because I couldn’t make the Pesco I had work on my IO-470, regardless of how it was hooked up.

 

[bobgoodman]

mine is a 67B025. i know that doesn't help, but i happened to have the 8130 form sitting here. don't know which way it turns. but it works. on an io-470k. most hydraulic pumps only work one way but i suppose it would pump backwards if the hoses were reversed but may not build enough pressure.