anestg
Member
Hi john thanks for your input. It is a Waratah 622b head. It was paired right from new from the dealer as far as I know. The attachment rotate is plumbed from a small pump behind the pilot pump.
-
Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
Link belt 240lx hydraulic head scratcher
- Thread starter anestg
- Start date
jcb jeff
Senior Member
The manual is a JCB manual from the training school as a part of dealer training but i guess although these machines are similar there may be differences .
Does the dipper sorry stick drift about 1 foot and then stop if so suspect the load hold check valve on main hyd valve block.?
You say now that you have tracking problems is that just one side or both tracks when this happens try the track individual as this possible may be main pump fault or regulator on side of pump.
In the hyd pump bay do you have two filters one spin on like and oil filter and one that is a aluminum housing with a 15/16 nut forged into this filter body if so worth a change of these as this is servo filters. The alloy one you may need to take off an put in a vice if its really tight never broke one but it gives you that impression.
If the dipper check valves check out fine this eliminates fault with ram if you take the pipes as per the other post
As per the the first text neg control can tell you a lot of what is going on or not in some cases.Will see if i can take a better picture for you.
Does the dipper sorry stick drift about 1 foot and then stop if so suspect the load hold check valve on main hyd valve block.?
You say now that you have tracking problems is that just one side or both tracks when this happens try the track individual as this possible may be main pump fault or regulator on side of pump.
In the hyd pump bay do you have two filters one spin on like and oil filter and one that is a aluminum housing with a 15/16 nut forged into this filter body if so worth a change of these as this is servo filters. The alloy one you may need to take off an put in a vice if its really tight never broke one but it gives you that impression.
If the dipper check valves check out fine this eliminates fault with ram if you take the pipes as per the other post
As per the the first text neg control can tell you a lot of what is going on or not in some cases.Will see if i can take a better picture for you.
anestg
Member
I talked to the mechanic and my machine doesn't have the hose burst check valve option. Jeff where abouts on the main valve would I find the regeneration valve? As for your question on the tracks it travel straight it just seems to be very slow for 2 to 5 seconds and then it seems to kick out of it. Almost like a spool isn't shifting. Behind the pump door it looks exactly like this picture I found on the Internet on my machine. 
jcb jeff
Senior Member
The servo pump or pilot pump filter is the one in the top left in picture on the pressure hose from the pump in a aluminium housing next to the accumulator with the 15/16 nut on the bottom. Main pumps are different as we have a pilot pump mounted on the end of the main pump JCB anyway. Do you have another pump on the top by chance?
On the tracks when its hot if you can stall the track in turn with a an old bucket pin against the track frame mind your hands don't get caught my brother squashed his thumb this way bit of a mess to say the least and see if it drags the engine down as this is a quick way of testing the pumps as if you stall one track at a time you are only getting either p1 flow or p2 pump flow not a combined flow masking a fault .
As far the regeneration I will have a look in the book later and let you know might be slightly different though .
As far as tracking as you say the tracks appear slow for a short time and then become normal again if you were to select another service and feather say boom up or dipper out does this speed the tracks up.
On the tracks when its hot if you can stall the track in turn with a an old bucket pin against the track frame mind your hands don't get caught my brother squashed his thumb this way bit of a mess to say the least and see if it drags the engine down as this is a quick way of testing the pumps as if you stall one track at a time you are only getting either p1 flow or p2 pump flow not a combined flow masking a fault .
As far the regeneration I will have a look in the book later and let you know might be slightly different though .
As far as tracking as you say the tracks appear slow for a short time and then become normal again if you were to select another service and feather say boom up or dipper out does this speed the tracks up.
jcb jeff
Senior Member
item marked red is the regen spool (spool port M) the two filter looking items on the top are the restrictors for the neg control lines Not sure if this is the same as your valve block but would think it would be close though .Hope it helps .
jcb jeff
Senior Member
This is the slew over dipper priority valve on the side of the valve block cant see it being this but might be worth a look neg control will tell you a lot need two gauges and two t pieces to tap into regulator on pump.
pt1 and pt2 on the regulator on the main pumps.Pump nearest the engine should have two hoses on regulator 90 degree 1/4 bsp on jcb this is at th rear of pump and nr the top and it should be the hose nearest the flywheel and on the other pump facing straight down with straight fitting both 1/4 bsp again and pt2 should be the furthest from flywheel you will need a t peice on each and two gauges of 0 -60 bar or 10-1000lb in2 oil at about 50 degrees C / 122 Fanestg
Member
Yes there is another small pump on the other side of the pilot pump towards the motor. Yes you are correct, tracks are sluggish when stick acts up,but if I feather the dipper out it speeds tracks up to normal. I was watching pressures and with no service selected p1 had 1800 psi on p1 and p2 was normal at around 400psi. This is after pulling dipper back and not touching any controls. If I bump dipper forward it drops p1 down to around 400psi as we'll. would this mean that a spool is sticking and stroking p1? I took some videos today of pump pressure on screen and the problem of how the dipper free falls after pulling it in until you push lever for dipper out.
jcb jeff
Senior Member
when you feather stick /dipper your are combining both pump flows in the valve block so if you had a pump problem this masks the fault. No abnormal noise from pumps or brass like particles in the hyd oil by chance?
This could mean that your pumps are not being stroked up so as the regulator on the pump is not working correctly telling the pump swash angle to change to increase flow/pressure.
Neg control will tell you when a spool is selected and if it cuts the oil supply to the pump regulator to enable the spring to over come hyd pressure in the regulator thus increasing pump flow /pressure. This will tell you what's happening.
This could mean that your pumps are not being stroked up so as the regulator on the pump is not working correctly telling the pump swash angle to change to increase flow/pressure.
Neg control will tell you when a spool is selected and if it cuts the oil supply to the pump regulator to enable the spring to over come hyd pressure in the regulator thus increasing pump flow /pressure. This will tell you what's happening.
anestg
Member
It was a nice day here today(not raining),so I thought I would tear into the main valve and start checking all the reliefs and ports that Jeff showed me. Pulled it apart hot. Pulled spool end caps. Pulled arm 2 spool out. Looked good ,moved freely. Pulled arm 1 spool ,hmmm stiff. It moved very stiff for the first inch. On closer inspection spool had scoring and a small wear spot were chrome was rubbed off. I'm so glad to have found the problem. Thanks to everyone for your help and encourment.
anestg
Member
One more thing Jeff. Do you or anyone else know how to reset the "service due" on the display? Thanks
jcb jeff
Senior Member
Hi
Glad you have found something wrong will the spool clean up or is it worse than that .The neg control would of shown you had a problem there straight away so its a good check when you issues as you can see what each spool is doing plus you will know if the pump should be stroking up at well.
As regards to the service light not sure on link belt can you send a pic of the dash as it might be the same as an early jcb? if not try posting on this forum on how to turn the service indicator off on the link belt I would think you can do it from the panel in the cab though.
Glad you have found something wrong will the spool clean up or is it worse than that .The neg control would of shown you had a problem there straight away so its a good check when you issues as you can see what each spool is doing plus you will know if the pump should be stroking up at well.
As regards to the service light not sure on link belt can you send a pic of the dash as it might be the same as an early jcb? if not try posting on this forum on how to turn the service indicator off on the link belt I would think you can do it from the panel in the cab though.