Combines CR970

[JHEnt]

Its not your hydralic oil reservior temp thats too hot its the case drain oil at the hydro motor. Remember that hydro drives are closed center systems meaning that the oil is constantly sent from pump to motor. Oil is only added as some escapes. Only the oil that slips past the pistons returns via the case drain line to the reservior. The oil cooler as I remember is plumbed in with the chargepump pressure regulator. Oil that is dumped off at the regulator is sent to the cooler. This cools oil going back to the reservior not the oil recirculating in the hydrostat. My 1st thought would be if the temp sender is accually working properly. The sender is threaded into the case drain line at the top side of the hydro motor with standard pipe thread. My 2nd question is if yours is one of the 1st combines builtIJ Early 2002 models. If so did it have the hydrostat and motor swaped out by either the factory or the dealerIJ The early hydro units built by Sauer_Danfoss were defective. The would push the brass bushings out of the piston bores and then grind them up sending the grindings down the line to the motor. last summer I drove a CR970 about 35-40 miles from the dealership to a farm show. The outside temp both going and comming back were about 95-98 degrees F. That combine never cut back on the ground speed. If anything running wide open down the road should have created alot more heat than running through the field in a lower gear. I would almost bet you have a bad temp sender.

 

[buckshot]

First off, don't listen to twinspinner and john holland. Acting like an A$$ never made anyone want to help you out of a problem and it gives us the reputation of being sniveling jerks. I am of course assuming they are doing their best for you and are not ignoring you. Second, it could be the sender as was suggested. lastly, any time I ever had hydraulic oil get hot was because there was a restriction in the system. Oil gets hot when it bypasses. Have them look at the basic plumbing from your pump to the motor and back and if they don't find anything, have them check for a restriction on the cooling circuit. Does the hydraulic oil get hot even when the machine isn't movingIJ Something could be dead-headed in some other circuit. It's in there somewhere. If the problem drags on, ask for a free loaner. If they won't do that, feel free to throw a hissy. That way they can take the combine to their shop and do some serious work on the machine and you won't be left twisting in the wind. If the unit is under warranty, New Holland should pay for the loaner. I don't know what your laws are where you are, but in Alberta the company has to either fix the machine or provide a replacement within X amount of time. I forget how long but I think it is within three days. Good luck with your problem. I hope you are back making laps in no time.

 

[crrules]

check the cooler bypass valve, i believe it is located near the cooler towards the rear of the combine, at least that is where it is on a 940. good luck, post back if you find the solution

 

[NHD]

I know of one CR970 that last fall(2002) had a similiar problem in that the symtoms were the same as yours. NH traced the problem to Sundstrand the mfg. of the hydrostat. They replaced it. I don't know if they changed the plumbing. I think NH should fix it. Call Joe at NH harvest support 717-371-2228. Also, the computor is supposed to slow things down as the oil over heats. Just like newer trucks that stop the spark to some of the cylinders till things cool down.

 

[deetsch]

I own and operate a CX860 and had a hydrostatic overheat condition happen at 5:00am in southern Manitoba (on a day where no dew set in and it was time to catch up). It baffled me because the air temp was down around 15C. I lost ground speed just like you are reporting. Root cause was that I couldn't see how much thistle seed was hanging in the air and getting into the cooler. After cleaning it I had no problems. But since it happened once, I put the hydraulic tank and closed loop temperatures up on the display the next time we were operating in 30 weather. When running 6+ mph in 2nd gear, with a full grain tank, and the engine pulled down to 105 to 110% I saw hydrostatic temperatures within a couple degrees of critical, but the reservoir was 15 to 20 cooler. My thoughts on the issue are this: 1) The cooler is working, this is just a local hotspot, maybe not enough oil is being bled out of the closed loop. 2) I don't think that combines are designed to continuously run below rated engine speed and they suffer cooling capacity loss due to the fan slowing down proportionally. 3) I also know that hydrostatic pumps and motors have varying efficiencies based on speed, displacement, and pressure - perhaps one's t_m gear choice could contributeIJIJIJ Finally, my machine is at the dealer for off-season service right now. If they find a problem I'll post it and the solution. PS. Is there anybody out there with Goodyear 900x32 front tires that has a serious problem with them being out of roundIJ Is New Holland or Goodyear doing anything about thatIJ

 

[Sando]

Pete, I am running a 940 here in CQ and today (38 C outside)I could get the the hydro to heat to a stage where it would start to cut ground speed back. It would start to slow down at 98deg C. I was running wide open in 2nd gear - about 13k's. If I stopped and changed to third gear and continued on at 13k's the thing cooled down to about 83deg and stayed there. Went back to 2nd and watched it heat right back up again so ran the rest of the day in 3rd. I would normally expect the best result out of any other hydro by going back in gears and stroking open the hydro to get the desired ground speed. The other thing I will say is that I wasn't working the machine hard at all so I don't know what would happen if we started to load the thing up. I"ll stay tuned to see how you get on. Cheers, Sando

 

[humpo]

I to have the same problem. I am in Australia and just today driven our machine from the dealers yard.It was about 35 degrees "C" and after about 40 minutes on the road got the same warning message. Temp showed 105 degrees, once it got back to about 88 degrees it was happy again but didn't take long to get back up to 100+ degrees. I have heard of this problem in other CR's in the area.

 

[NHD]

I forgot to mention that louie told us at the factory pre-delivery school to run in 2nd gear in the field instead of 3rd as we always do with the TR's. The CR does run faster in 2nd than the TR so we used 2nd all season. It really does take a lot of your horsepower to move the heavy CR through the field, especially with a full 300 bu. hopper. Something like 52% just to pull the combine across the field with a full hopper.

 

[JHEnt]

The gear selection on CR is accually a 2 speed gearbox and a 2 speed hydraulic motor. Although without looking it up I can't say which gear is in which combination. The hydro motr runs about half stroke in its high speed and full stroke in its low speed. Heat can be created in a hydraulic system from too much oil leaking past. Such as a hyd cylinder, when deadheaded a cylinder with a piston leak will become hot to the touch around the position of the piston while the rest of the barrel will remain cool. It maybe a problem with the motor itself.

 

[2rotorsrule]

Joe went home for the winter I'm pretty sure. Its up to your dealer until mid-May next year if you want to talk to Joe