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case 850 right track wont run in hi, looking for Case hyd tester

markmc60

Well-Known Member
Joined
Aug 8, 2011
Messages
47
Location
Texas
I am looking for a case hyd tester or, someone with the knowledge of it to explain what exactly the tester does in test 4 for and 850 trans pressure reg test. I have the book, gauges, flow meter, just loses me in that test. my 850 is not pulling in right track in hi, but it will in low, we currently have the dozer elevated and both tracks off the ground, right stops after a few seconds running in low, and barely moves a little in high, makes no difference forward/reverse. left tracks just spins its butt off. I also hear and noise in the trans when the right is engaged, I dropped the right track off the sprocket and the noise is still in the trans area.. I suspect an issue in the right hi/low shaft. I know we are going to pull the trans, new clutch discs and steels on the both hi/lo shafts and the forward reverse since we have access(old dozer). I also would like some one to help with low pressure in the trans, has anew trans pump but pressure is around 225(dash gauge). I know it is supposed to be 275(-+15) 260-275, my book dosent show how to adjust the regulator......just shim it up?
 

gggraham

Senior Member
Joined
Feb 13, 2009
Messages
587
Location
London Ontario Canada
Occupation
Licensed Heavy Duty Equipment Mechanic
I'm assuming you are talking about a straight 850. Make sure your RH brake pedal is fully releasing not sticking slightly, when applied lightly it declutches the track. I've seen a brake pedal stick and cause the Left or Right side to declutch. I've also seen the declutch spools stick in the declutch position. It's easy to check, remove the brake line from the declutch spool, insert a screw driver into the spool where the brake line attached. Push on the screwdriver you should feel a slight tension as you move the spool rearward. Release and it should spring forward, compare the right to the left. That's the easy checks out of the way. See attached diagramdeclutch.jpg
 

markmc60

Well-Known Member
Joined
Aug 8, 2011
Messages
47
Location
Texas
I'm assuming you are talking about a straight 850. Make sure your RH brake pedal is fully releasing not sticking slightly, when applied lightly it declutches the track. I've seen a brake pedal stick and cause the Left or Right side to declutch. I've also seen the declutch spools stick in the declutch position. It's easy to check, remove the brake line from the declutch spool, insert a screw driver into the spool where the brake line attached. Push on the screwdriver you should feel a slight tension as you move the spool rearward. Release and it should spring forward, compare the right to the left. That's the easy checks out of the way. See attached diagramView attachment 249120

we will try that. But the brakes have never worked since he got this dozer.
And this issue just started. And like I said the trans pump dash pressure shows about 225. We will look at the brakes.
 

markmc60

Well-Known Member
Joined
Aug 8, 2011
Messages
47
Location
Texas
thanks for the reply from ALRMAN, I asked a question of him in a message, he responded................ to my RESEARCH question............. thanks to the responders.
I think he has a bad hi clutch pack on the right hand side. we are going to get some time and pull the transmission. it is out in the woods and we have to pull it there and load the trans on a trailer
transport it to my shop and see what we can find. any idea how much the trans weighs? by it self and with the finals still attached.
i truly do appreciate all the replies.

G'day Mark,
I'm assuming this is an early model 850? (mid 70's vintage)

You need to figure out if you have a hydraulic (pressure) or mechanical issue.
If the transmission pressure gauge on the dash still works - it should show the same (or near the same) pressure in whatever range you are in.
Once at operating temp & at an idle (low pump flow) flick through each range & note if the pressure drops - particularly in RH high.
If the pressure drops, there is likely leakage occurring either in the shaft end cap (worn/broken oil control rings) or the RH high clutch pack piston seal - or both.
You could disconnect the oil supply to RH high & test the pressure directly into the supply fitting at the control valve & then Tee into the circuit to see how much lower the pressure is from the first test.

OR you could swap the HI/LOW hoses over & see if the problem goes to RH Low (note the operating position of the controls will be opposite) - showing a supply issue OR if the fault remains in RH High - an oil control ring or clutch pack issue.

Usually the fault is with the oil control rings - however most people keep operating like that for many hours & pressure is sent to both the HI & Low at the same time.
As most operators push in Low - pressure is also being sent to High - dragging it like a brake which usually overheats the oil & also burns out the clutch pack.
When this occurs there is often some evidence in the transmission suction screen...... lots of bronze clutch plate material.

Hope this helps.
It's always best to start a thread to discuss this type of problem on the public forum as the information will help countless other people in the future, long after us old Case blokes are dead & buried - but I've already now told you what I would have told you in public chat, & I don't like repeating myself... ;)

Cheers
alrman

To steal ideas from one person is plagiarism. To steal from many is research
 

markmc60

Well-Known Member
Joined
Aug 8, 2011
Messages
47
Location
Texas
  1. markmc60 said:
    i'd like to know more about this problem as well, what was the fix?, and I am looking for a case hyd tester or, someone with the knowledge of it to explain what exactly the tester does in test 4 for and 850 trans pressure reg test. I have the book, gauges, flow meter, just loses me in that test. my 850 is not pulling in right track in hi, but it will in low, we currently have the dozer elevated and both tracks off the ground, right stops after a few seconds running in low, and barely moves a little in high, makes no difference forward/reverse. left tracks just spins its butt off. I also hear and noise in the trans when the right is engaged, I dropped the right track off the sprocket and the noise is still in the trans area.. I suspect an issue in the right hi/low shaft. I know we are going to pull the trans, new clutch discs and steels on the both hi/lo shafts and the forward reverse since we have access(old dozer). I also would like some one to help with low pressure in the trans, has anew trans pump but pressure is around 225(dash gauge). I know it is supposed to be 275(-+15) 260-275, my book dosent show how to adjust the regulator......just shim it up?
    Hey Markmc60; which 850 do you have? It kind of sounds like the shaft seals may be bad for the right track. They are located under the front shaft cover on the front of the trans housing under the floor plate. Post some pics if possible and a serial number would be helpful.

    Coy Lancaster, Nov 24, 2021 Report
    #23 Like + Quote Reply

  2. markmc60 Active Member
    Joined:
    Aug 8, 2011
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    39
    Location:
    Texas
    Coy Lancaster said:
    Hey Markmc60; which 850 do you have? It kind of sounds like the shaft seals may be bad for the right track. They are located under the front shaft cover on the front of the trans housing under the floor plate. Post some pics if possible and a serial number would be helpful.
    we checked them, as a matter of fact, one had the hook piece broken, we replaced it, but that did not fix the issue.

    markmc60, Friday at 1:22 PM Report
    #24 + Quote Reply

  3. Coy Lancaster Senior Member
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    markmc60 said:
    we checked them, as a matter of fact, one had the hook piece broken, we replaced it, but that did not fix the issue.
    If you can do pressure test at control valve that may tell you what you don't want to know.

    Coy Lancaster, Today at 6:44 AM Report
    #25 Like + Quote Reply
 

markmc60

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Aug 8, 2011
Messages
47
Location
Texas

  1. markmc60 Active Member
    Joined:
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    Messages:
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    Location:
    Texas
    Coy Lancaster said:
    If you can do pressure test at control valve that may tell you what you don't want to know.
    we swapped the hoses at the control valve, the issues stayed on the right track, so its in the right side, my guess, burned up HI/LO clutch packs. our trans pressure (using the dash gauge) is only 220psi, according to the book it should be 275 +/- 15, so 260-290. we plan to pull the trans and bring it to my shop, beat with a baseball bat and see if that helps. kidding, we will open it up and look it over, there is a leak some where. has a new trans pump. Does anyone have a ballpark weight on the trans and the finals, might just bring it all back and take the opportunity to look over the finals as well.

    markmc60, Today at 7:44 AM Report
    #26 + Quote Reply

  2. melben Senior Member
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    If you have a good working dash gage you can zero in on the problem, with warm oil all clutch pressures when checked individually should be the same regardless if your reading is not up to spec, if one lever position checks lower than the rest a leak is indicated in that clutch circuit. I however agree with ALR, a flowmeter is indispensible for this type of diagnosis and a pump test is in order. I am retired almost 9 years and have my own flowmeter, there has got to be one hanging around out there somewhere

    melben, Today at 8:40 AM Report
    #27 Like + Quote Reply

  3. markmc60 Active Member
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    melben said:
    If you have a good working dash gage you can zero in on the problem, with warm oil all clutch pressures when checked individually should be the same regardless if your reading is not up to spec, if one lever position checks lower than the rest a leak is indicated in that clutch circuit. I however agree with ALR, a flowmeter is indispensible for this type of diagnosis and a pump test is in order. I am retired almost 9 years and have my own flowmeter, there has got to be one hanging around out there somewhere
    there is no difference on the dash gauge when we go foward reverse in hi or lo, we blocked the dozer up and just let the tracks spin.......... in HI it will creep the right track a little bit1/8 rotation them just stop, in low it steady creeps but not smooth the left side, hauls ass in either position.
    well I sure would like to see inside the flow meter just to see what they are doing, how it works, Hell, I'll make my own. when I start looking for a "flowmeter" folks eyes glaze over and i get the deer in the headlights look..
    wanna sell yours?...........think I could get a few pics of the inside the meter box to see the plumbing and what the valves are doing/controlling. you know what they say, a picture is worth a thousand words.

 

markmc60

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Messages
47
Location
Texas
Melben.
Do you think I could get more info or maybe a pic of the inside of your flow meter? Or if anybody has 1 for sale, lease, rent
 

alrman

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@markmc60 - the flow meter is only really required to test the transmission charge pump efficiency.
Even though "the book" - describes flow testing the entire transmission - in the real world - even when I worked at a Case Dealer - a flowmeter was available but those test tools/manifolds were never available.......& we never bothered to make them.
We would diagnose any transmission fault comparing pressure differences.
As I have already suggested to you - compare the inner workings of the transmission by swapping the supply pressure hoses from LH to RH & see if the issue swaps sides or remains in the RHS.
You may need to get new hoses if they are old & gone hard in order to do this.

OR you could swap the HI/LOW hoses over & see if the problem goes to RH Low (note the operating position of the controls will be opposite) - showing a supply issue OR if the fault remains in RH High - an oil control ring or clutch pack issue.

Have you drained the oil or checked the suction screen yet? This could supply clues to internal transmission issues.
 

markmc60

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Joined
Aug 8, 2011
Messages
47
Location
Texas
@markmc60 - the flow meter is only really required to test the transmission charge pump efficiency.
Even though "the book" - describes flow testing the entire transmission - in the real world - even when I worked at a Case Dealer - a flowmeter was available but those test tools/manifolds were never available.......& we never bothered to make them.
We would diagnose any transmission fault comparing pressure differences.
As I have already suggested to you - compare the inner workings of the transmission by swapping the supply pressure hoses from LH to RH & see if the issue swaps sides or remains in the RHS.
You may need to get new hoses if they are old & gone hard in order to do this.



Have you drained the oil or checked the suction screen yet? This could supply clues to internal transmission issues.
As I said. We did swap the lines at the control block on top of the trans the left handle operated the right track and right handle operated the left track. The failure stayed on the right side. And yes when he replaced the ring he replaced the filters. Nothing was found in the filters. I only asked a out a flow meter because others keep asking for the numbers. And I don’t have any numbers. The dash gauge is the same 225psi left or right, swapped lines or not. In my mind either hi clutch pack or pinion bearing/gear.
Just trying to gather experience and knowledge.
 
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