Hanix 15b-2: Strange Tracking Issue

[mowgli]

Guys ,

Thanks for your time to read this, appreciate any help!

I wonder if anyone could give me some hints on how best to diagnose this one or even any ideas on what this could be:

I have a Hanix 15b-2 small excavator that works great digging however:

1. Stalls instantly if I move the track levers in the opposite directions (one forward or one back)
2. Will move but labours if both sticks in the same direction but eventually recovers, unless I try to doze then it bogs down quickly and stalls.
3. If turn the machine with only one stick all works fine.
4. No 1 does not happen if I'm raised off the ground.
5. The left track high speed mode does not seem to work.

So I'm thinking its something to do with spool or a drive....but not entirely sure the best way to go about diagnosing this.

Could someone give me some pointers or better yet an answer if you've seen this sort of thing before

Thanks in advance

[Muz]

I take it you are running the engine at full revs ?

[mowgli]

Yeah muz running full revs...if I don't even tracking straight fwd or back will kill it.

Should have said I've changed fuel filters and checked pump is getting fuel so I think its something hydraulic related..I think 😃

I don't understand why having one lever fwd and one back would have such an impact..its a quick immediate stall.

[Muz]

I don't understand why having one lever fwd and one back would have such an impact..its a quick immediate stall.

Because it creates a lot of drag, and loads the engine heavily as the pump will have to produce maximum output to perform the manouvre.

It sounds as if somone has bumped up the relief pressures in the block too high, does stop ending any ram cause the engine to die also ?

Your double speed travel will be a faulty solenoid most likely (assuming theres a switch somewhere that controls the speed change?)

[mowgli]

No nothing else causes that stall behaviour...relief valve kicks in when I dead end bucket etc...only seems to be drive related.

On the high speed
The strange thing about fast speed is according to manual it's one out feed from rotary that feeds a tee piece to each of the drive motors...one works other doesn't....I'm gonna try swap the lines see if it makes other side work.

[2414.ginger]

I wonder if someone before had the lines off, and then put them back wrong.
Not sure if this would cause the problems to which you refer, but never be surprised at what someone else has got wrong.

[Muz]

No nothing else causes that stall behaviour...relief valve kicks in when I dead end bucket etc..

Ok the reason for asking is that the track motors are treated as a top priority service in the block just like the boom lift, dipper , and slew, so if a relief was faulty, you would expect some other service to cause engine labouring too...

forensic thinking on the other hand ..... could the previous owner have been annoyed at having no high speed travel ... bypassed the actuating solenoid and plumbed the digger to 'only' work with high speed travel ..... which would labour the engine with more load ? means also its tracking power would be halved.. so reluctand to turn etc

[mowgli]

The high speed does work on the right hand track and i tested the solenoid it appears to work...I can see this if i raise the machine and step on the high speed pedal.....but very strange that it doesn't on the left as I just double checked manual and it says its fed from a single port output from the rotary valve and this is then T 'd to the drive motors high speed ports....I guess I need to check this T section out as a next step to see whats going on there...make sure to Gingers point its actually connected to the correct place!!

I'll get a pressure test done Muz to see what port1/2/3 relief valves are set to make sure the basics are ok...guess I better buy a test kit! :)

Thanks a lot for the pointers, appreciate the help, I'll let you know how I get on, apologies if I'm asking basic stupid questions..hydraulics are v new to me

......hate these dark nights can't get anything done!

[AndrewMawson]

On my 803 someone had replaced the high/low servo flow and return lines that operate the spool on the track motor the wrong way round on one motor. Result was that one motor was always in low speed but the other changed to high speed fine.

simple job of unscrewing two hoses and swapping them round, but took a lot of diagnosing !

[Muz]

could be !!! ... just a matter of tracing the lines back to the orbital valve then .... easy to get them mixed up around there ... done it meself

[mowgli]

So plugged in pressure gauge to ports 2 and 3....cant get the bloody thing into 1 not enough room gonna need to try adjust valve.

I have a question when i plug into two it shows no load until i use slew etc and all seems well.

If port 3 is plugged in i get 50psi straight away without touching anything.....is that normal?

[mowgli]

sorry should have said 50 bar on port 3 without doing anything!

[mowgli]

Ok worked it out looks like its the pilot pressure on pump no 3....just need to get into that port 1!

On the track high speed mode I disconnected the high speed hose from the problem side.....seemed to leak oil constantly don't know if this is expected. When i hit the high speed button it did start to fire a constant stream of oil out....so looks like its def the correct hose!

Scott

[mowgli]

Managed to test all the ports:

Port 1: 175 bar relief (also worked out this drives the left dr)- whats strange is this seems to sit at about 10 bar even when not doing anything is that normal?
Port 2: 175 bar relief (also worked out this drives the right dr)
Port 3: 50 bar constant 170 bar relief when using dozer blade.

Also forgot to mention i have a PTO pedal if i press this with nothing attached it hits 150 bar and then the engine stalls out similar to the drive problem...may be red herring but thought i'd mention.

Any ideas on what to test next to try figure out why this stalls when under drive load but fine digging?

Thanks!

[v8druid]

Managed to test all the ports:

Port 1: 175 bar relief (also worked out this drives the left dr)- whats strange is this seems to sit at about 10 bar even when not doing anything is that normal?
Port 2: 175 bar relief (also worked out this drives the right dr)
Port 3: 50 bar constant 170 bar relief when using dozer blade.

Also forgot to mention i have a PTO pedal if i press this with nothing attached it hits 150 bar and then the engine stalls out similar to the drive problem...may be red herring but thought i'd mention.

Any ideas on what to test next to try figure out why this stalls when under drive load but fine digging?

Thanks!

dead ended service ... oil no where to go ..... relief ought to kick in and dump to tank ..... I'd be looking to see why it doesn't ..... and what else it services ??