Volvo EC15B weak tracking problem

[Muz]

I know we relentlessly talk about EC15's here sometimes .. which is fine ..Ive owned many over the years .. I still own 3 and all have played up at times, and Ive learned a lot , and helped share fixes over the years, as have many of you too which has helped save us all a few bob .. its why this whole place/forum is here .. but Ive come unstuck on this one, partly as my attentions are devided these days

Volvo's tech guy or SMT in Scotland as they are now known has been very helpful so far but I dont want to plague the guy..

The problem is weak track function .. on the old XR XT models you just opened up the MRV on track circuit .. problem solved.

The B model is different to the XT or XR in its block architecture ... the simplest way to see this it is when you sprag and let one lever go .. the remaining powered track gets double the oil flow to increase the turn rate unlike the older XT XR models

THe EC15B block appears to have only one MRV .. across the board for tracks , Aux, slew .. so anyway the tracks having gone weak on this one .. I tested the valve block and got 190 Bar .. at the main relief .....terrific I thought ? seems above normal .. so I made a test rig to check the pressures on the track motors
IMG_0131[1].jpg

Howd you like that fellas ? .. this is where I feel bad for you lads you need to keep a good relationship with your local machine shops to do this kind of test .. fortunately Ive got a shed full of bits and a crimp machine to make up these rigs .. what I'm looking for is loss of pressure through the orbital valve and if the tracks are weak in pressure .. but they aren't ... TBC

[v8druid]

I know we relentlessly talk about EC15's here sometimes .. which is fine ..Ive owned many over the years .. I still own 3 and all have played up at times, and Ive learned a lot , and helped share fixes over the years, as have many of you too which has helped save us all a few bob .. its why this whole place/forum is here .. but Ive come unstuck on this one, partly as my attentions are devided these days

Volvo's tech guy or SMT in Scotland as they are now known has been very helpful so far but I dont want to plague the guy..

The problem is weak track function .. on the old XR XT models you just opened up the MRV on track circuit .. problem solved.

The B model is different to the XT or XR in its block architecture ... the simplest way to see this it is when you sprag and let one lever go .. the remaining powered track gets double the oil flow to increase the turn rate unlike the older XT XR models

THe EC15B block appears to have only one MRV .. across the board for tracks , Aux, slew .. so anyway the tracks having gone weak on this one .. I tested the valve block and got 190 Bar .. at the main relief .....terrific I thought ? seems above normal .. so I made a test rig to check the pressures on the track motors
[ATTACH=CONFIG]4111[/ATTACH]

Howd you like that fellas ? .. this is where I feel bad for you lads you need to keep a good relationship with your local machine shops to do this kind of test .. fortunately Ive got a shed full of bits and a crimp machine to make up these rigs .. what I'm looking for is loss of pressure through the orbital valve and if the tracks are weak in pressure .. but they aren't ... TBC

You'm gonna have to rename this place the EC15B forum shortly Muz ...... taught me a lesson already .... never buy a fkr

[Mattir]

I know we relentlessly talk about EC15's here sometimes .. which is fine ..Ive owned many over the years .. I still own 3 and all have played up at times, and Ive learned a lot , and helped share fixes over the years, as have many of you too which has helped save us all a few bob .. its why this whole place/forum is here .. but Ive come unstuck on this one, partly as my attentions are devided these days

Volvo's tech guy or SMT in Scotland as they are now known has been very helpful so far but I dont want to plague the guy..

The problem is weak track function .. on the old XR XT models you just opened up the MRV on track circuit .. problem solved.

The B model is different to the XT or XR in its block architecture ... the simplest way to see this it is when you sprag and let one lever go .. the remaining powered track gets double the oil flow to increase the turn rate unlike the older XT XR models

THe EC15B block appears to have only one MRV .. across the board for tracks , Aux, slew .. so anyway the tracks having gone weak on this one .. I tested the valve block and got 190 Bar .. at the main relief .....terrific I thought ? seems above normal .. so I made a test rig to check the pressures on the track motors
[ATTACH=CONFIG]4111[/ATTACH]

Howd you like that fellas ? .. this is where I feel bad for you lads you need to keep a good relationship with your local machine shops to do this kind of test .. fortunately Ive got a shed full of bits and a crimp machine to make up these rigs .. what I'm looking for is loss of pressure through the orbital valve and if the tracks are weak in pressure .. but they aren't ... TBC

Interesting. Following this experiment..

[Muz]

You'm gonna have to rename this place the EC15B forum shortly Muz

I Know but ... these problems could be the same on any digger ... and the symptomology and methodology are all going to be the same .. which was the point I was trying to make in my opening post .. but didnt ... anyways

the pressures at the test point read exactly the same .. 190 Bar .... with the track stalled out. Interestingly, I put the dozer down, jack the machine slightly, and gradually get the machine to stall it .. thats how weak these tracks are.

IMG_0133[1].jpgIMG_0137[1].jpgIMG_0138[1].jpg

So there can be no loss of pressure through the orbital valve .... Are my guages not accurate I wonder ?

Next I'm going to test another EC15 main relief that I have in the yard and see what it reads with the same guage .. I bet its gonna be 190 Bar .. which puts me right back to square one.. and I'm gonna have to phone a man

[Muz]

Well that was interesting ... plugged into main relief test point and got this... 170 Bar .. exactly what it should be .. and this machine works perfectly

IMG_0143[1].jpg

This is the test point here IMG_0140[1].jpg

Pilot pressure test point is this one IMG_0142[1].jpg


Innards of the beast IMG_0139[1].jpg


And now its time to utter the well worn phrase ... 'what the hell is going on" ?

So atleast that proves my guages are accurate and removes them from the frame as being dodgy

[Mattir]

Well that was interesting ... plugged into main relief test point and got this... 170 Bar .. exactly what it should be .. and this machine works perfectly

[ATTACH=CONFIG]4115[/ATTACH]

This is the test point here [ATTACH=CONFIG]4116[/ATTACH]

Pilot pressure test point is this one [ATTACH=CONFIG]4117[/ATTACH]


Innards of the beast [ATTACH=CONFIG]4118[/ATTACH]


And now its time to utter the well worn phrase ... 'what the hell is going on" ?

So atleast that proves my guages are accurate and removes them from the frame as being dodgy

Great. As a biproduct you produced perfect instructions how to measure the pressures.

But. The answer to the question might be found in the lifeline between the upper and lower part of the doug: the rotary feedthrough or connection or joint or whatever it might be called. It has myriads of seals and they are under constant wear. I would investigate that part, and it could be tested by having the pressure gauge in the final drive and rotating the cabin and observing for some changes (?)

[Muz]

I would investigate that part, and it could be tested by having the pressure gauge in the final drive and rotating the cabin and observing for some changes (?)

Now why didnt I think of that ? Good point .. I should have tested it in several positions but did not well thats mondays job

[v8druid]

but why are you getting 190 bar anywhere Muz, if the MRV is set to 170 bar ????

TBH I can't see that rotating the super is going to give you any different results
if an o ring is leaking it will leak in any position
... an electrical slip ring could give fault in varying positions, but fail to see how a rotary coupling could

[Digga]

Did you get this sorted out Muz? I have a 2011 EC15C that struggles to turn right. If I'm going up a slight hill it simply stops...

[Digga]

While I was fitting new tracks last night, I found that the right-hand idler wheel was knackered which explains why it doesn't like turning right!
Are these Idlers repairable or will I need to buy a new one?