I’ve tried two dealerships near me, no one can fully answer this question for me, hopefully you guys help clear up my question! I have a 2003Case 70XT skid steer, low flow machine. under 700 hours Question: What is the ((Potential)) auxiliary flow rate UP TO the attachment quick couplers? I’m aware Case installed the common ½” body size quick couplers that are only 12+/- gpm. I’ve researched the Danfoss gear pump on back end of engine that supplies hydraulics to the loader arm, bucket tilt and auxiliary attachment couplers, my research results is about 19-21 gpm, just depends on who you ask… I can’t find any flow rates for the main loader control valve or the auxiliary (foot) control valve. I assume the main loader control valve can handle over the Danfoss pump flow rate, what I don’t know… did Case put any flow restrictions orifices in the output port on that valve that supplies the auxiliary (foot) valve and how many gpm can the aux foot valve potentially supply the attachments taken the existing 12 gpm couplers out of the equation? I know you’re wondering… so here’s what I’m trying to do! All my attachments run great on the restricted flow rate caused by the ½” body size 12 gpm rated quick couplers, but now I have a need to run a hydraulic gear box (helical pier/pile drive unit) that can handle 24+ gpm I would like to give that gear box as much flow as possible that my machine can potentially give it!!! If I went to the trouble and expense to upgrade the aux. quick couplers to lets say a ¾” body size (allows about 40 gpm) on both the machine and the attachment(s) side would I get much more flow than I have now? Even a few more gpm over the 12 gpm coupler restriction rate would make a big difference in regards to rpm to that gear box output, which would give me more production per hour. I contacted Case customer service, they were zero help!!!! they just told me to contact my local dealer again, who I've spent two hours on the phone back and forth, they don't know anymore than I do! The specs from Case for this machine says 21 gpm auxiliary!!! How can that be...LIE?? I still have the original Snape-tite/Parker 1/2" body 74 series quick flat face couplers http://www.snap-titequickdisconnects.com/products/drybreak_non-spill_couplings/74_series/index.html plumbing to couplers is all 5/8" steel tubing and fittings. Has anyone ever used a flow meter on this machine before and after the quick couplers? Thanks!!
Usually testing of the pump efficiency is done from the aux couplers now days. Your machine has a T fitting at the pump, which was used for the flow tests. I think you are greatly over estimating the flow loss through the couplers. I believe the same ISO flat face couplers are on the newer equipment (although the coupler housing is different on the new equipment). You will likely not get 21 gpm, as this is the full throttle flow, But I would expect you to get near the 17gpm area. The last flow test I did on a new SR250 was as follows Case spec is: Auxiliary hydraulics 22.5gpm actual readings at couplers are: 22gpm no load full throttle 2000rpm for rest of tests: 19gpm, 1400psi 18.7gpm 1800psi 18.5gpm 2200psi If you believe that you are not getting full flow to your aux circuit, make sure you are getting full stroke out of your pedal. If that's ok, then check your cracking pressure of the main relief.
Gary, Thank you for sharing the test results you did on the SR250! Your right... I may be "greatly over estimating the flow loss through the couplers" When I called Parker the tech told me 12 gpm max flow rate for that coupler and that goes for ALL 1/2" body couplers, which is as far as I know that's the size and style we all use for low flow machines. I'm glad you tested the actual flow through the coupler this helps me a lot!! Based on your test I bet your right, 17 gpm would be close. Why didn't my dealer know this, or better yet why didn't Case share this with me, they must have known that coupler they installed on just about every low flow machine out there can deliver more than the Parker 12 gpm specs!! "If you believe that you are not getting full flow to your aux circuit, make sure you are getting full stroke out of your pedal. If that's ok, then check your cracking pressure of the main relief." Gary I do not think I have a malfunctioning flow problem, the machine only has 700 hrs and runs like new! I was merely trying to take a proactive approach with this new attachment and I assumed when Parker told me 12 gpm max, that's all the coupler would allow, kinda like a flow control valve works. I would assume 12 gpm is recommend flow rate and not max, over the 12 gpm would cause excess heat. The Larger 3/4" body might be a good alternative to help with heat build up.
Here's what I found on google: http://www.colemanequip.com/SpecSheets/70XT.pdf
I wish you better luck with your dealers next time. The customers don't always get to talk to a experienced technician. Time is money, and having the techs answer phone calls doesn't make the dealership any money. But having inexperienced people answer the phone doesn't put much faith in the dealership. I doubt that you will have any heat issues with the attachment you intend to run. If you were going to run a broom, or mower, or something requiring constant flow all day long, then you may run into heating issues. I have done flow tests on the xt series as well, but I don't have any exact numbers available to give you. In my opinion you will likely be fine with your current set up. Best of luck. Keep us posted.
Thanks Dave! I already this, but its helpful for any ones looking for specs on the 70XT
Gary, Thank you again!! I'm going to more forward with what I have (change nothing) I will watch my hydraulic heat and make corrections if necessary.