CNC 19 #1 Posted 12 hours ago I have a C160 automatic the hydraulic valve is leaking fluid. I have replaced all the hoses, had the cylinder and value rebulit . it still leaks at the valve assy. I am at my wits end! Has anyone had this problem or any suggestion? Thanks Share this post Link to post Share on other sites
peter lena 9,924 #2 Posted 11 hours ago @CNC only thing I can think of is o ring seal , rolling due to dry installation ? as tightened , if not properly lubed , the rings , grab and bind , twisting smaller tighter , making a leak area , regularly used SUPER LUBE , hydraulic lubricant , my suggestion , pete Share this post Link to post Share on other sites
ebinmaine 79,385 #3 Posted 10 hours ago 1 hour ago, CNC said: rebulit Can you see exactly what seam or joint is leaking? Share this post Link to post Share on other sites
CNC 19 #4 Posted 9 hours ago 46 minutes ago, ebinmaine said: Can you see exactly what seam or joint is leaking? It looks to me like it leaks from the hose that is 11 in. long that goes from front of valve assembly to back hole in the cylinder I have a friend that is coming over after the 4th who knows more about hydraulics to check it out and see where he thinks it is leaking. 2 Share this post Link to post Share on other sites
pfrederi 20,791 #5 Posted 9 hours ago 23 minutes ago, CNC said: It looks to me like it leaks from the hose that is 11 in. long that goes from front of valve assembly to back hole in the cylinder I have a friend that is coming over after the 4th who knows more about hydraulics to check it out and see where he thinks it is leaking. Possible the O ring was damaged during installation.... The hose end could be an SAE #6 ORB (O Ring Boss) or SAE#5 ORB #6 threads are 9/16NF #5 are 1/2" NF The orings are Dash #906 or Dash # 905 3 1 Share this post Link to post Share on other sites
Handy Don 16,841 #6 Posted 6 hours ago ORB fittings depend on smooth, continuous, debris-free seating of the O-ring between the body of the fitting and, in this case, the cylinder body. To be ready when your friend comes, have the IPL handy when s/he comes. 1 Share this post Link to post Share on other sites
953 nut 67,048 #7 Posted 5 hours ago Torque settings for ORB fittings should be made in accordance with this chart. Too tight will kill the "O" Rings. You will need to use a crows foot placed to the side of the torque wrench to get a correct reading. JIC ORB Size SAE Thread Torque Size SAE Thread Torque 4 7/16-20 140 In/Lb 4 7/16-20 220 In/Lb 5 ½-20 180 In/Lb 5 ½-20 260 In/Lb Dash# 905 O Ring 6 9/16-18 250 In/Lb 6 9/16-18 320 In/Lb Dash# 906 O Ring 8 ¾-16 550 In/Lb 8 3/4 -16 560 In/Lb 1 2 Share this post Link to post Share on other sites
pfrederi 20,791 #8 Posted 5 hours ago That is great info!!!! I probably over tighten mine 2 Share this post Link to post Share on other sites
ebinmaine 79,385 #9 Posted 4 hours ago 45 minutes ago, pfrederi said: That is great info!!!! I probably over tighten mine I definitely do. Bear tight. 😬 Share this post Link to post Share on other sites
WHX?? 57,185 #10 Posted 1 hour ago 3 hours ago, 953 nut said: Too tight will kill the "O" Rings. Absolutely true. They must be torqued to spec. Share this post Link to post Share on other sites