D5m works perfect for 40 min. then starts to lose priority valve pressure only at idle. If I keep the rpm's up the priority valve will stay at 420psi and it gets worse as I continue to use the machine to after hour and a half the pressure drops to 150 psi at idle but pressure increases with rpm to 410 psi at full throttle and machine will still operate and shift as long as I hold throttle wide open. Yesterday it just stopped pushing while under heavy load of pushing dirt after 2 hours of use. Trans filter assembly felt very hot. But I still could hold the throttle wide open to get the priortity valve up to 410 psi and it would still go into gear to were I could park the machine but just couldn't push dirt anymore. Any thoughts?
I forgot serial number 3DR-00510
Are you doing the measurements of the priority valve pressure with the brakes applied or released.?
They are released.
At operating temp the pressure goes up and down with the throttle with either the brakes released or applied.
Test specs are 3 points. Low Idle with brakes On & off, then High Idle with brakes Off. The critical one I see is at Low Idle with brakes on - minimum 425psi. If the brakes are on then there should be no pressure losses via the brake circuit. At High idle with brakes Off the spec is 475 +/- 22 psi. How does your tractor perform against this spec.?
At high idle with brakes off I only get 410psi when its at temp. 425psi when its cold brakes off or on. At low idle with brakes off or on at about 180 degrees on the gauge is about 150 psi. The pressure fluctuates 1 to 1 with the throttle almost like its a rpm gauge when everything is warm at temp. Sure seems like its pump related.
Low all round then, both at Low Idle and High Idle, brakes on or off. In this case the test protocol is to have all systems at normal operating temperature. Are you using SAE30 TO-4 in the transmission.? How many hours on the tractor.? Original transmission pump.?
Thank you for your input Nige- All my tests numbers were at operating temperatures. Oil is the Delo Torque-force sae30 TO-4 specially for the CAT transmission. Hours are 4870.0 and its the original pump.
It would be interesting to see the results of some of the other tests on that attachment
Well I did test P1 pressure at operating temp and it too would fluctuate with the throttle. High idle was 350psi low idle was about 100psi. I'm thinking that maybe testing the other pressures while the initial pressure is not correct will just show everything to be bad at low idle? I'm begining to drain the oil tank and remove the pump starting today.. I could be wrong, but I think I have to resolve the poor pressure at idle problem, before doing more test.
So update to my d5m problem. I removed the pump and disassembled the pump, then measured some of the clearances of the pump shafts and the bearnings inside the transmission pump. I found that there is .0035" clearence on 2 of the shaft to bearnings clearence and .0025 on the other bearings which I think is .003" and .002" worn out. I believe it's to be only .0005" clearence when new. There is also a vertical Grove worn into all the bearnings that looks like oil can escape. You can feel the Grove with your finger nail.
Unless that's just an oil stain on the tooth of that lower gear in your photo (or a wear lip on the tooth directly below it) then that pump's fcuked........
Thank you for your reply, and yes what you pointed out is bad along with what you can't see in the pictures is the huge clearence of the shafts to bearning clearence. I'm ordering a new Pump on Monday. Thanks for your input.
i would like to see the faces under the gears and inside the cases Mark
Here you go, 3 section pump, 1.converter scavenger 2. Control section, 3. Torque converter section
TBH I wouldn't have expected a pump with less than 5000 operating hours to look like that inside unless there had been a major amount of contamination flying around the system for quite a while. What sort of history do you have for the power train oil system.? Or have you only bought the machine recently.?
I bought it with a little over 3000 hrs on it and I have to say I did not change the trans oil myself when I got it, I trusted the company whom I bought it from that told me it was serviced, which is part of the problem. I changed the fluid only a few months ago and the magnets at the pickup had quite a bit of very fine material on it. Obviously I will be changing filters and cleaning everything again. Now I just worry for what else might be affected. Thanks
Ok, new trans. pump installed, has a little more priority pressure at high idle 440psi and low idle is about 420 psi. Still loses pressure as it warms up. Everything works perfectly until it warms up. I have found that if I pull back on the lever steer handles about at least 1" the priority pressure goes to full pressure at about 410 psi and to about 420 if I pull both handles at same time at high or low idle. When pulling either lever steer handle only 1" the priority pressure goes up to the 410psi and the power shift works forward or reverse perfectly. Let go of the lever steer handle and the priority pressure goes down to 300 psi and it will not engage forward or reverse. The brake on or off does not effect the pressure loss high or low idle. So looking for where to go with this now? Thanks-
A replacement priority valve I would have thought. We fought with an issue identical to yours on a D9R a few months ago. Have you pulled apart the transmission hydraulic control valve and rebuilt/resealed it yet.?
I have not rebuilt anything in this machine except the new trans pump this last week. Looking at the control valve, it looks like it's just spools. But I will look closer at it and what is involved to remove it.
That is exactly what is going on in my dozer... mine is a D5H, 1DD654... but i never watched the pressures on the priority valve, just watched P1 and P2´s. When oil is cold everithing runs fine, once it starts to heat up it starts by having problems in engaging, when really hot it even shows mickey mouse behaviour when using the brakes, it even disengages once one step on the brake, with THR cut. once THR ted up it reengages... I haven´t had time to replace the pump, but i suspect it will not solve the matter... its my intuition.
See attached parts breakdowns of the Transmission Control and the Priority Valve. Personally I would suggest re-sealing both of them, the necessary parts are highlighted in yellow. Also check the needle bearings carefully and replace if they are worn or have seized rollers. While you have both valves apart apart check the free length of all the springs, highlighted green, and closely inspect every one of the orifices. Any that are plastic personally I would replace because they tend to erode on the inside. I'm just not sure which orifices are plastic and which are brass in those two valves in particular. D&A instructions also included.
Thanks for your input- yes I replaced the pump and it did not fix the problem.
Nige- Thank you for taking the time to post these drawings and marking the parts, I do appreciate it. thank you-
Did you try pulling back on one of the steering levers just a little like 1" or so and then see if the power shift works when its warm. I'm reading and trying to figure out were the fluid goes when not pulling the steer lever, it might be the indicator of were the leak might be?
After doing a lot of reading in my cat manual in the systems operation section, I find that the clutch's have 325psi of pressure at idle and in neutral and when you begin to pull either of the steer levers it removes that pressure from the clutches which disengages the clutch and that may be what is leaking. The clutch pack may be leaking? But I find the book has a few things identified as the clutches. Namely the clutches in the control valve and then there is the actual clutch packs?
No, I did not tried that, cause in my understanding of the system steering/brake clutch packs are in same circuit as trans. PV prioritizes fluid to release brakes as PRK brake action is done by spring action on the clutches(experts pls clarify) same for clutch action. One question your M is not finger tip control? Thing is, my problem appears to be a faulty pump… as I read 21bar cold @P1/P2 slight less 1.5 bar At idle. 16/17 hot , values @WOT, in idle they are low, very low… like 1… Normal system calls for 24bar Hot Idling. But if we have a very small leak on this spring clutch packs it may lead to the low press to start with… As of u, I’ll be checking the pump first, I have a shop that can bench test it for small fee. If it turn out to be too obvious w’ll replace it. I’ll report back…
They made them both ways, but My D5M LGP is a lever steer, not finger tip.
Nige- After thinking about when my d5m problem all started, I want to explain how I ran it just before the problem started. I was moving my machine a mile up a very steep hill 45 degrees or more on a big ranch to clear a fire road at the top of this mountain and when I got to the top is when my problem all started. It worked perfect before I went up the hill. After reaching the top to were the fire road was to get cleared it was just about on a level grade. At that point the machine would not shift into gear unless I held it at high idle. The trans fluid was right at the full mark on level ground. But I read that it needs to have 10% more on steep grade (another 3 to 5 gallons) or it will starve the system of oil and pressure. So the question is what part of the system will get damaged first from starving it of oil after a very continuous long uphill steep grade with not enough oil in the system for a steep grade? Does that harm the actual disc's clutch pack?
Your explanation makes perfect sense. When you are working on steep slopes according to the O&M Manual the transmission should be overfilled by anything up to 15% of the stated system capacity to ensure that the pump suction is never starved of oil. It sounds like that's what happened. Nasty things happen when the clutches in a transmission under load run short of oil, as in they burn to a crisp PDQ.
Nige- I'm still working on finding the problem. I have taken apart the priority valve and really did not find anything obvious, I purchased new springs for the valve. I did remove the bolts holding the priority valve to the bevel gear case and found all of the 5 bolts were wet with the trans- hydraulic oil, which I find not normal for a cast assembly were the bolts should be dry. Is it normal for those to be wet with oil? O-rings did look OK on the back of the valve. Can not really inspect the inside of the valve for cracks.
I think the clue to it may be that when you start to pull back the steering clutch levers the pressure starts to disappear. As you commented in Post #27 above, that seems to suggest a leak (or leaks) somewhere in the steering clutch system. Poke a piece of wire down each of the bolt holes. Does it go right through or hit bottom.? If it goes right through you have your answer.
They are blind holes. They do not go through to the inside of the bevel case. So the bolts I would think, should all be dry. Thanks for your continued input. After doing a lot of reading of the systems operation from the manual- The way it works from the priority valve is; oil first goes to the steering and brake clutches at low idle, brake off, 310 and 400 psi. Only after that is achieved;, then the pressure builds at the priority valve that goes up to 425psi, then it sends oil to the transmission. So if the steer clutches or brakes had a problem that slowly looses pressure, then that will result of the priority valve not having enough oil pressure to get to 425 for the transmission to work. But what I'm puzzled with is you would just think that only pulling one of the steering clutches would cause the priority pressure to raise up. But in this case if I pull either steer clutch independently they both will cause the priority pressure to raise up the same amount. What are the odds that both steer clutch's would be damaged exactly the same amount. So there might be a common problem with the steering clutch valve spools or some other commonality between them that I'm trying to figure out before I start taking all the tracks off, ect. to get to the steer clutch pistons. Thanks-
Been folowing this tread as i do have same problem in my dozer, despite mine is a H model. Shouldn't be much diff if not exactly same components. But i recall reading through another thread here with somebody complaining the same problem in same era and model machine. This may be a common problem... I haven't done much to correct it on mine. Haven't work with it either...
I'm suspicious of the priority valve housing with the oiled mount bolts. My trans. filter was also collapsed at the very top to were the hydrulic pressure had the power to bend the steel housing on the filter.. the priority housing is very thin between the Port's and very thin and close to the mount bolts and the symptoms are of something that gets worse when it warms up, Stay tuned.
Update, no problems with the priority valve. When it was removed, I took a picture of the mounting location on the bevel gear case. The upper right tube goes to the steering/ brake valve and the left tube goes to the transmission, the middle hole goes directly into the gear case for the priority valve to spill its extra oil. The lower left tube I believe has to do with torque converter. Not sure about the lower right tube. I inserted my air chuck into the upper left trans tube and it pressured up and blew back out toward me. When I inserted the air blower to the right tube to the steer / brake valve I could hear it escaping somewhere and it never built pressure from my 150 psi compressor. I believed it should pressure up and blow back at me but it didn't. I reassembled the priority valve and placed gauges on the right steer and brake valve test ports. At idle cold was 300 psi for the steer and 380 psi for the brake and the same at high idle cold. 450psi for priority. After 45 min of running the steer went down to 240 and the brake about 370 at idle. And about the same at high idle. Priority was down to about 400psi at idle and 420 high idle. When pulling left steer lever the right steer pressure barely increased to 250 but the brake increased to 380 and the priorty went up to 450psi. So from the air gun in the tube test and the results from the gauge, I believe the problem is in the steer clutches from going up the long hill that I describe in previous statement. I believe testing with the priorty valve off the machine is a help to diagnose. Any suggestions? Thanks
Attached the System Operation document for the powertrain. You may find it useful. Have you checked any pressures on the torque converter inlet/oulet.? That might be interesting. Bear in mind that the oil from the priority valve passes through steel tubes that are expanded into position inside the holes in the rear case. That's how the oil gets to the steering clutches and brakes amongst others. Cracked/split tubes are not common but neither are they an unknown occurence.
Thank you for the manual, I have the complete Cat service manual and have read the system operation several times now, I retain a little more everytime I read about the different components. I will take note to maybe back feed air pressure from the top of the steer/brake finally drive test ports on top of the housing to maybe detect a cracked tube. Good idea about the tubes. I will put a gauge on the torque converter test port. Thanks Nige.
Both of them. Converter inlet pressure is measured cold and outlet pressure is measured hot.
I think you will end up pulling the final drives and steering clutches. The steering clutches are oil applied so when you pull the lever you are dumping the pressure. You will probably find the seals in the steering cutch failed and you can also inspect the tubes while you have the clutches out.
Ok, I tested both the Inlet torque pressure 130psi high idle on the priority valve and the outlet on the torque relief valve 110 psi high idle. I removed 2 track shoes so I could get to the rest ports on top of the left steer/brake housing on the final drive. Tested the left steer port and removed the transmission fill cap above, inserted my air house to the test port and held my hand on the 2" fill opening and the air just pressurised the bevel gear oil reservoir. I would think that test port should hold 300psi before spilling to the reservoir. I was just holding the air pressure with my hand and it pressured the transmission reservoir. What do you think?
130psi maximum with cold oil at HI is the spec IIRC. Did you test the outlet pressure with the converter stalled against the brakes in 3rd speed and with everything at normal operating temperature.? 110 psi sounds awfully high, I would have expected somewhere in the range 50-60. The spec will be in the manual.
I just tested it now after warming it up again high idle 3rd speed with holding foot brake. It's about 75psi outlet.
I did test the torque output again after reading your post, after warming up the machine, the output pressure in 3rd gear high idle was about 70- 75 psi. What I would like to know and you may not know the answer, is when testing the steer clutch at the final drive steering test port, should it hold pressure from a air gun and not just flow right out of the bevel gear case fill tube as mine does? I also had someone pull back the left steer lever, which made no difference in the pressure coming out of the fill tube. I would think it should hold some amount of pressure. Thanks
Spec is 68±10 psi so that's about right. Maybe a bit towards the high end of the range but so is the inlet pressure so not exactly unexpected.
Thank you for your input Nige-
I tried another method of testing the steer clutches before taking them apart. I used my air leak down tester on the left and right steer clutch test port above on the final drive. They both had exactly the same leak down 84%, meaning I believe they both have an exact same size bleed hole in there pistons for when you shut the machine down it releases the clutches pressure. That's my theory anyway. The system operations section does not go into it that deep. If the steer clutches had a problem, I would think the leak down would be different from each side.? Thinking my trans oil leak is coming from maybe the tube that go's from the priority valve to the steer/brake valve is cracked as Nige mentioned. Now to figure out how to test that.
You would need both valves removed and fabricate blank plates to go over the ports that seal 100%. One plate would need a fitting on it to allow you to pressurize the tube. Apply shop air pressure and check if it holds or leaks off.
Since u are in such a deep troubleshooting efford, remind us, the reason of your problems started by the machine not engaging, or having problems engaging when hot, and NOT steering, would it be so out of the box checking the TXM operation with the steering system bypassed? so as the braking system? Blocking the PV to the steering/brake side would do it. Despite it need pressure in Brake system to "walk" that would not be a problem to check press at P1 and P2 ports and rule out TXM clutches system leakage. BTW driving the machine up slope or dwn slope , side slope or anyother slope would not starve any of the clutches of lube oil, no more than it would in a flat spot, as this lube is coming from same pump intake. Unless u have a really really low oil level, or other issue in lube system. Either way pump would cavitate so much that it would not be unherdable and machine would get stuck imediatly. just my opinion. nice job u´re doing,
There is a small note in the Cat manuals that when on steep slopes over 45* to be sure to overfill the transmission 15% of oil because the pump may starve of fluid. And yes you would know if it was starving by its reaction by it being noisey or feeling it. The reason for me going the steering and brake direction is if the priority test pressure is not at full pressure at low and high idle, you have a problem with the steer/brake side of things. You would start checking the transmission side of things if the priority pressure is good at low and high idle. My priority pressure goes down to 200 psi at low idle after 1 hour of operation and then will not shift. If I pull 1 of the steer levers the priority goes to full pressure. The priority valve only gives the transmission it's needed 425psi only after it gives the steer/brake valve it's full psi. So no need to block off the steer/brake valve side when you understand how it works. Besides that it would be a monumental project to make a block off plate to test it as you suggested. Thanks-
Update- The attached photo is inside the bevel gear housing while the machine is running at low idle, I used a camera with a light to be able to get this photo and I also have video that may be to large to post here. I wanted to see if the tube that supply's the steer/brake valve was spraying or leaking without having to remove the priority and steer/brake valves and make test plates to pressure test. What your looking at is the tubing to the steer/brake valve inside the bevel gear case. The tube that looks red or dark in color in the middle of the picture is the return to tank tube from the steer/brake valve that has oil flowing out when the pressures are below the check valve psi values. I have other video and pictures of that flowing oil out. That tube actually rises up to about 6" vertical and is just a open tube at the top to where the oil just flows out from the top. Question is, should there be oil flowing from that valve when it is not at the required pressures for the steer and brake spools? I would think it should not until it reached the required pressures set by the shims. I have other video and photos of the tubes from the priority valve that shows no leaks or any spraying. What do you think Nige? The tube below the one that is leaking oil is the pressure tube from the priority valve.
I dunno what to think. If I was stood next to the tractor what I would be trying to do is work out the function of each tube and where it carried oil to/from. Never having seen one of these in the flesh it's hard to comment. Even if it was a bigger tractor like the ones I am more familiar with I would still go back to first principles and trace where fluid was going to/from, etc.
I do understand what each tube does in this picture because I have studied the diagrams of the valves out of the service and parts manuals. My method of using a camera saves a lot of time from having to take things apart. Now I will take apart the spools out of the steer/brake valve and see if there is any debris in one of the orifices. Using the camera through the transmission fill tube will only work for seeing a few suspected problems in the gear case and is not a solution for seeing other problems. It just so happens that in this machine the steer/brake valve and priority valve tubes can be seen from the end of the fill tube while it's running and if there was a split tube you would be able to see it spraying or dripping oil.
Any developments?
Update- Did not find any problems with the steer/brake valve, no debris in it. So here is what Cat does not tell you in there books and after talking to more then a half dozen Cat technical people, which none of them know how to test the steer/brake system. I found the smoking gun of the problem with my steer/brake system. At lest I believe I have. When I had the steer/brake valve off the bevel gear case, I used my shop air hose and blew air in the right and left tubes for steer and brake tubes (4 of them). The right side held pressure and blew the tip of the blow gun back at me for both the steer and brake tubes, the left side blew all of the air pressure out the trans fill tube for both the steer and the brake tubes. So that's my smoking gun. So I put the steer/brake valve back on and wanted to know if you could test it with the valve on the machine. I hooked up to the test ports on the steer/ brake valve for just the right and left steer. You can only test this with the machine off. You have to pull back both steer/brake levers to where they begin pulling the brakes spools, this is what makes the two sides completely independent for testing the steer clutches and it also works for the brakes as lo g as you pull the levers back far enough. Put air pressure in the test ports to see how well each side holds air. You could use a leak down test also. Mine just blew air right in and out of the trans fill tube. So the order of testing is if the priorty pressure is low, the problem is on the steer/ clutch system. If the priority pressure is always at its required pressure and you still have problems it's in the transmission side of things. Hope this helps someone.
I’m glad that you have got to the bottom of the problem but more than one person has been trying to tell you to look at the steering/brake system from very early on.
Besides you Nige, there was only 1 other person that had a comment on this thread of what it probably would be, but did not have a method of testing it and that was only a few weeks ago, not early on. My method is an easy test that I would think Cat should have in there manual. I've read other post on this forum to where they just replace everything without knowing what is really wrong and hoping it fixes it I did the same thing replacing my pump. Question is, do I just rebuild the side that's bad or rebuild both sides. Could get a few more thousand hours on the good side, you just don't know.
And that was 3 weeks ago. Personally I’d suggest that you rebuild both sides. If one has failed the other must be “tired” by now That’s why even though you didn’t know until now which side it was if you had pulled both sides at the start and rebuilt them the problem would have gone away.
If I got it correctly , u had the brake/clutch valve assy off the tractor and found no evidence of a problem? and still the right and left side of this dual valve system behaves diff and sound to be the problem in your dozer? This weekend i plan to look a my dozer, and the idea was to remove the TXM pump and send it for testing and repair if needed, but in this case i´ll also look at the priority valve pressures and the Brake clutch Valve system to see if it mimics your finding. As i mentioned before, i´ve seen people complaining of this very same problem in this era machines here and other forums, with apparently no solution.
I noticed a post on here of a guy just changing everything and still had the same problem after parts changing. Then he either still hasn't fixed it or he fixed it and didn't post what his findings were. Which we all would be curious. The main thing to do before anything is check pressure on the priority vavle at operating temp low and hi idle, and that will direct you to where to start looking as I stated in my post above. As Mobiltech mentioned above it's probably the steer clutch's, and he had that answer after I mentioned my priority pressure went up when I pulled either of the steer levers. Well that wasn't hard to figure out after I mentioned that. But I like to be sure myself and found a way to test which steer clutch side it is, maybe somebody knew how to test it but nobody posted how to. So my answer is Your Welcome! Good luck finding your problem.
Yep after some time dealing with several types of machinery including airborne machinery, i can conclude that books and manuals do not speak with us... and certain procedures are hid, or they are too obvious if one know the system by heart. Lot of people in forums search answers for their problems, but once they fix theirs forget about it. Personally I like to share my solutions and or findings. Experience also tell´s me that a tired oil pump is never the root cause of this type of problems, unless its too obvious due to catastrophic failures. About your testing... maybe i did not got it well, u have done static testing on the Brake/steer clutches too? i mean bypassing the valve? cause i understood the problem was on the valve? is this correct? If u did test the steer/brake clutches how have u done it? Thanks.
If your 5h is the same as a 5m and you have lever steer with powershift transmission, this is how you test the steer clutches. The steer/brake valve has 4 test ports on it, made for PD242 quick coupler (amazon.com). The right and left outside ports are for the steer clutches. (You may have to remove the left side male quick coupler and put on a 90 degree -6 ORB male x -6 ORB female and then put the straight male coupler back on because there are hoses in the way.) I had to remove the emergency brake 4 bolt cover to install the -6orb 90. With the engine off, put a bungee cord around both lever steers and pull them both back as far as you can. This will make each steer clutch independent for testing. Connect the PD242 coupler (amazon.com) with just an open hose (no gauge on it) so you can inject shop air one at a time to those outside test ports and see it pressures up. (You may need to remove the trans fill tube cap for the test to let the air escape if one of the clutches leaks air) (You can also try a leak down tester to be more accurate for the test) They should hold pressure. You can also test the other inside test ports for the brakes but you need to remove the bungee cord from the lever steer controls and allow them back to there normal postion.
I should say that you can just remove the test port male fittings and put the air hose right on the valve to test so you don't have to buy anything.
So, there´s no problem in your Steer/brake valve... problem is upstream in the cluch pack... i understood reverse. 5m same weight as 5h diff engine and other gadgets available like finguer tip control... TXM with lever control seems to be much alike. including same problems... thanks
Yes, I believe the problem will always be in the clutch pak on all machines. Probably will never be the valve.. My problem is the clutch pak, the left side does not pressure up.
The reason. I thought it was my valve is because my filter collapsed and may have let debris into the valve. But that was not it.
Ok, Got the point But did u find any problems steering or braking with the levers when operating the machine? Anyway , do u have steering/braking system operation explanation in your Manual? could u share this part? Or someone in the forum... Maybe i´m missing something , cause i understood the system operates by releasing the brake clutch pack from spring action for service brake, and by adding/removing pressure to the piston for active braking, either by foot pedal or lever action. And Steering is achieved by releasing spring action by adding pressure to the pack. would apreciate an explanation
The problem I had with my machine is I would loose priority pressure after an hour of operation which got worse as I used the machine and it would only effect the ability of it not going into gear unless I increased it to high idle where as it would then get 400psi and then it would go into gear. Watching the priority pressure gauge, the pressure would drop to around 200 psi at low idle after an hour or so which is why it would not shift into gear because the priority pressure needs to be around at least 400psi for the spool to shift over in the priority valve for the transmission to get oil to shift. I did explain this at the beginning of this thread. I think you need to read the system operation section in the Cat manual for your machine so you can understand how it works. The steer clutch gets 325 psi + -20psi as soon as you start the machine and remains under pressure until you pull back the steer lever which then reduces it to 0 psi. Both steer clutch's are co-mingled from pump pressure when they are not pulled. When you pull both steer levers back and hold them there, they are separated from each other and separated from the pump to were they can be tested with the machine off as I directed you in the above post.
That is exactly what mine does, i start it and it run perfect for an hour hour and half or two hrs then starts to have problems to shutle when cuting gas, keeping the ability to shutle at WOT, if one continues it starts to act funny in geting off gear and in gear. I don´t have the manual thats why i asked if someone could share it. Nevertheless , probably we can conclude something weird happens in the cluch packs, or in some O rings in piping, wich is much easier to fix than if it was inside the TXM. In 2 or 3 days i´ll post my findings. Regards
In this thread Nige posted the operation section of the manual that you can download. Maybe a page or 2 back. Nige is very helpful with posting parts of the manuals.
Hy gentleman... Looks like my dozer(d5H) experiences the same fault as this one (D5M) ... when i operate the steer brake levers P1 acts funy ... it goes up and drops... left handle more than right... sorting out where F%$#" PV port is located
It's under your feet when sitting in the seat. Remove the plate under your feet.
Buh... did not found the PV test port @ valve assy(behind filter) I wonder where is that thing, picture in manual is a bit blured to understand where that thing is located. A good picture would be apreciated. Anyways , found some interesting repairs in that thing... the most interesting was that at some point someone replaced the oil intake hose to the TXM pump, this gipsys used a silicone hose and clamps like those used in auto tunning. Thing is the hose has evidence of colapsing , i could not test it, cause i was alone and nobody to help in throtling... ( i'm pretty convinced this is not an issue) nevertheless i going to replace this hose. Meanwhyle, despite i couldn't measure PV pressure, i could get an idea on how much the levers movement afect P1. Left handle rises about 500 kpa, right some 350. Other interesting thing is the P1 with the parking brake aplied comes down to 750Kpa, and when released P1 goes up to 1500. This testing was done @ 1000RPM after 2.5 hours working, when the shifting problem is really evident. Apreciate comments, pls have patience first time diging into this mechanics.
Because I don't have the same machine I can't tell you how to find the PV test port, but I believe in your year machine it is made as 1 casting with the filter housing and the test port ( if it has one) should be on that filter/PV valve ( the filer is part of the PV valve) . Like I pointed out before, the order of testing always starts with a gauge on the priority valve pressure. When you have the required pressure at the priority valve 420psi at operating temperature or after running the machine for an hour is when you want to test the PV pressure. If it stays up around 420psi after an hour or so running or so only then can you test p1 pressure. You keep testing p1 a d that's not how you do it. You will not figure it out if you keep trying to test p1 pressure. That is only for the transmission, You have a steer clutch problem and you only test that by way of PV pressure test..
Yes thats true, the PV is in the filter assy, belive it or not there´s no port on the PV body, nevertheless there is a port over the Filter cover labeled Pump Press, could that be the port? The manual show a test point , no way it resembles the filter cover... and they say its on right side of Steer/brake valve.... no way i see those ports there... i understand your machine is not same as mine... its just the next model ahead... Tested P1 just cause i couldn´t find the PV test port , nevertheless it show some interaction when moving the levers... as u mentioned yours had... BTW understood by reading manual that the steer clutches are opened by Lubrication fluid pressure and not spring actuated like the brakes, what didn´t made sense to me was: in absense of oil press they would disengage, and they do but that is not a problem as the brake clutch pack is dwn stream of driving power and will always secure the track hub in the absense of oil pressure. thanks again for your time.
I believe that port on the filter is what they mow call priority pressure, it is the first thing the pump goes to which is the priority valve.