Cat d8n converter temp, how hot should it get? Machine is 9TC serial number Ripping and pushing dirt the converter outlet temp got up to about 110 degrees c Then it seemed like the brakes were dragging, pulled up and it took 5 plus minutes for the converter temp to drop back under 100, radiator haha been cleaned and is running fine engine temp wise and trans cooler has been removed and cleaned. Changed transmission filter and it looked clean, machine is running in 35 degree plus weather, unsure when trans oil was last changed. Any help appreciated.
If it gets up to 110C at the end of a push it should fall while you are backing up for the next push. The high converter outlet temp alarm goew off at 125C so you are still a long way away from that. Was that at Low Idle RPM or something higher than that.? When the radiator was cleaned did you remove all the protection in front to get access into the corners.? It might pay you to get hold of an infra red thermometer and measure the coolant temps at the inlet & outlet of the radiator.
Low idle rpm As low as it will idle without shutting the throttle The main reason for stopping before it got any hotter was the machine had dragging brakes Which went away after the converter temp dropped Radiator has been cleaned inside and out and new thermostat fitted 91 degrees c on the top hose and it’s dropping to 74 on the bottom hose
Try idling it at medium throttle, say 13-1400 RPM. See if it cools down quicker. That temperature drop indicates to me there is a flow problem through the radiator, be that inside the radiator itself or somewhere else within the cooling system. The absolute maximum temp difference that you should see between top hose and bottom hose on a new radiator with everything in good condition is 10 DegC.
So if the engine isn’t overheating and there is a new thermostat fitted, what could possibly be wrong inside the radiator and how could it be ‘overcooling’ And if we have approximately 75 degrees out the bottom how does this correlate to the high converter temp and the dragging brakes.
Loss of flow by the water pump (loose or damaged/worn impeller is a possibility). Something else in the water lines partially plugged or restricted.? If the brakes are dragging under certain circumstances that could indicate all sorts of things. Transmission pump pressure below specification, problems in the priority valve, leaking brake piston seals, etc, etc. If the flow of coolant through the transmission oil cooler is not sufficient then it will not be capable of carrying the heat from the transmission oil away fast enough to the radiator. Hence high converter outlet temperature. All speculation on my part but it fits the facts as you have presented them. To dig deeper into the water lines arrangement would require Serial Numbers for both machine and engine, as there are quite a few different setups. Does your tractor have one water temperature regulator or two.?
Have you looked at the trans filter? It doesn’t take long with dragging brakes to warp the brake disks. Friction material will show up in the filter and suction screen.
New trans filter fitted a couple of hours ago It looked clean….. It has only had the brakes dragging for approximately 50 meters Then the machine was stopped until it cooled. I’m thinking now that I need to be testing the temperature drop accross the trans oil cooler, this will tell if the cooler is doing its job. Does anyone have any specs for this procedure
Was it cut open to check.? Any particles would be lodged in the bottom of the filter media pleats. See HERE for a good how-to video. Was the suction screen removed and inspected/cleaned at the same time.?
Temp drop across the cooler could vary quite a bit due to engine temp and volume of oil going through. You need to do some pressure testing. You need to know pump pressure , converter outlet pressure and lube pressure to get any idea what’s happening when it gets hot. Pump pressure measured at the filter. Converter outlet under the floor plate at converter outlet relief valve Lube pressure on back of trans case. Lube pressure is a good indicator of cooler flow.
I would add priority valve pressure to the list above. If something is going whacky in the brake system that ought to give a clue.
You might find the attached useful when you go testing.
Hey Guys , always leaning ... What gets me thinking is why would the brakes drag?, without someone stepping on the pedal or from a malfunction in the brake valve? If i got this correctly system is built around having pressure to realease brakes, without this pressure, it is not even possible to engage the trans, and if this pressure is lost the TXM go neutral.
“Learning”
Just thought I would say as you have a ripper the pin puller is linked into the transmission pressure, well the priority control line, Is this a Diff Steer or 2 tiller Tractor? loss of oil flow and pressure would put the brakes on or cause drag, the best way of having a look is to remove the rear plate but you will need to lash up 2 narrow strips of steel to bolt the round pressure boss onto the back case, then you can look in with the first thing you see is the priority control valve.
i see, what i can´t understand is: "pressure loss @ priority valve will cause TXM to go neutral" how can the brakes be draggued when TXM is in neutral?
The Transmission will mess about like move in 1st a bit forward but seem good in reverse, these transmissions are controlled via Boden Cables and there is a little filter in the valve block, the priority valve can leak off oil but still make pressure to lift the brakes, when the pressure drops the brakes come on due to mechanical spring pressure.
Machine is currently parked up. I have recently installed a new bevel gear seal as oil was leaking out around the yolk. When I dropped the trans plate down it was full of dirt, and I mean full, so much so it was nearly up to the driveshaft. It has not been off for a long time. all around the bottom of the converter was full of dirt so this would most certainly not have helped with heat dissipation. however, I would not think the brake issue should have happened when the oil got to 110 degrees. We are going to change the trans oil and add a 50W (as that's what's recommended in our temperature range) and run the machine and monitor trans temp/brake drag. If the problem persists, we will carry out pressure tests and I will update with what I find.
The front input shaft seal is not anywhere near the bevel gear, there is no seal on the bevel gear drive as it is inside the case.
So the plot thickens I have not had a chance to carry out any pressure tests on the transmission or converter due to not being near the machine. Operator has been running machine for approximately 2 days and trans temps are running fine…. Operating in approximately 38 degrees C weather, now after several hours of operation the hydraulic oil temperature alarm comes on for hot hyd oil The hyd temp is at 95C and he shuts down. We are going to change filters as we have no idea when they were last done It is not low on hyd oil. My questions are Could blocked hyd filters cause it to overheat the oil? The service manual lists approximately 11 things that can cause it to overheat but where should I start and can I check the cooler oil flow/pressure to make sure oil is actually being pumped to the cooler? Thanks
I’d suggest confirming what the gauge is showing with a temp gun as a first step.
Update: Due to miscommunication with the operator the hydraulic oil was 40L down and have since filled it up to the correct level and have had no further hydraulic overheating issues and running in 35 degrees c temps so that issue is sorted. Fitted new hyd filters aswell. Ran pressure tests on the brakes while working and all within spec ect Machine has been back to work and hyd and converter temps are running ok Converter is around 90 C and has new oil ect So now we are working in 35-40 C temperatures How hot should the engine run? Nige mentioned previously that he thought we had to greater temperature drop over the radiator Engine temps have been as high as 100 C Is this normal under these conditions? There’s no real spec in the book except it says that if the engine overheats the alarm will sound. So I guess the question is now are these normal temps given the situation and is it safe to keep running or should we be looking at the cooling system. Thanks
Based on that you really need to find a better class of operator........ Can you believe anything he tells you.? Have the temperatures you mention above, especially the coolant ones, been checked with a temp gun.? Need the actual temps from radiator inlet and outlet in your current climate conditions. What type of coolant do you have in it.? The coolant temperature regulator is set to be fully open at 92 DegC. When did the tractor last have a new one.? When was the radiator last given a good cleaning.? By that I mean all guards off (inside & out) and a deep clean, not just spraying water through the holes in an attempt to clean it. Fan belt condition & tension.? Fan pulley condition.?
Yes they were checked with a temp gun The machine was in the workshop and had a trans cooler clean, new thermostat and gasket aswell as a radiator cleaning product put through it, as routine maintenance. Belts and pulleys look in good shape, will check in more detail today. After it left the workshop it was put into some ripping and it was running 92C on the top hose and we were getting 76C out the bottom. However this was some months ago and it was not as hot then. The radiator has routinely been washed ect but it may need to be removed and cleaned further however it looks very clean externally.
Coolant is new and a 50/50 mix of Valvoline advanced oem 05
I'd suggest that you measure those temps again now the ambient temperature has increased. Up to 10 DegC difference between the top hose and the bottom hose would be the absolute maximum for a cooling system if everything (radiator, water pump, temp regulator, etc, etc) was in perfect condition. So what you had back then is way out of whack from what it ought to be. That's fine. It'll work. It can look fine from the outside when you're looking through the gaps in the guards. Has anyone actually removed them and taken a GOOD look at the radiator.?
Update Been a while Radiator was removed and cleaned internally and externally and was spotless. its not an original radiator its an upgraded Adrad fitted in 2018. We fitted a new cam and full set of lifters and clips while we were in there as cam had wear, put back to work on a 16ft cutterbar in CQ. We are running all day in 35 C plus temp with no stopping. So its 100% duty cycle on converter, and everything seems to be running fine Engine 100-105 C Converter got to 107 C hydraulics got up to 80 C Carried out brake pressure tests as per manual, all in spec we have since sacked the operator and got a new one. Machine is working very hard all day, and has done 130 hrs now without drama. Thanks everyone
The only thing in the cooling system we have not done is temp sender for the gauge and water pump, however some seem to suggest that 105C is not to hot for and engine thats working this hard in this temp.