Hey guys...just signed up so here goes......got a sp48dd ingersoll rand single drum roller.....run it about 30-40 minutes, vibrating and not, and the machine comes to a halt, might move a little and then lock up again.....cools off for 15 minutes and good to go, but hyd.oil not getting hot....sounds like the axle brake is coming on cuz when it acts up, the pressure light on dash for park brake comes on, so assuming it's losing pressure in that system.....drive motor has a charge relief valve and high pressure relief valve, and the propulsion pump has a charge pump on it.......any of this sound familiar? maybe a good way to check? don't have any pressure settings to go by...thanks
You will need to check charge pressure cold and hot, neutral and traveling both directions. If you have excessive internal leakage the charge pressure will drop and the park brake will apply. It may also be low enough that the servo will not stroke the motor swash plate. It should be an old Sundstrand 20 series pump and motor. Manuals should be available to download from the Danfoss website.
thanks a bunch Ben.....any help is appreciated......the charge pump looks to be on the rear of the propulsion pump, which then goes to the drive motor/pump in front of the axle?? wasn't for sure on how the flow went...all I got is a parts and operating manual..
Hey Ben.....lots of info on the Danfoss sites.....thanks again for leading me in the right direction....let me see if I can figure it out
Hello Ben, well this is what I got on this roller......hooked up gauge to port on bottom of pump (neutral, forward, reverse check) and everything looks fine cold, wide open neutral 360, both directions 300, mid throttle 270 neutral, both directions 250, idle was 240, both directions 200....20 minutes later (hot) neutral went to 110, mid throttle 240 and wide open 290 at idle.....both directions went to 20 at mid throttle and 240 wide open.....but when you gave it full throttle FAST, it goes to 40/50 and locks up....if you feather it it would move...now the longer you travel, neutral is 110 idle, 250 mid, and 290 wide open, and then both directions with mid and wide open goes from 250 mid/290 wide open TO 10, and locks up, even if you feather.....have to let it sit for 20-30 minutes off to cool and then back to normal....I don't know if the charge relief at the motor would act up like this or like you said internal leakage in the motor...looks like I can take system pressure at the motor manifold but wanted go get your thoughts first....any help would be appreciated
The fact that your charge pressure is dropping significantly indicates excessive leakage internally. Also you really should only be testing at full rpm.
Thank you sir......on that note, I will pull the propulsion pump and motor and send in both for a rebuild.....you have been a big help