You could try Reversing the polarity to the solenoid & see if it will push rather than pull. What are the dimensions of the hole in the solenoid & length?

Bob,
the coils are rated according to the following specs -
1. Push or pull?? (I am not sure how they achieve that electrically, but assume it is to do with the winding.)
2. Voltage - 12 or 24 VDC for the excavator??
3. Watts - quite a spread as this varies according to the loads generated on the spool when hydraulic pressure is operating.
4. Physical size ID OD and length??
5. External casing material??
6. Connector type for the wiring??
7. Method of retaining the solenoid on the core?? Can be a nut, circlip, or 4 screws through the housing on some models.

With all the above variables, there are literally thousands of different solenoids used.
If there are any numbers or brand names, that would increase your chances.
If not on the solenoid, look on the valve itself.

If you do chance upon the correct replacement, it will most likely cost between $30 and $100, certainly not the rip off $500 you have been quoted.

I have worked in hydraulics (mostly marine) since the 1970's so might be able to determine a replacement with a photo of the valve, or any numbers off the valve. Can't do if just from the solenoid.

Regards

Peter
PJK

Hi Peter..

It is a 12v system and it is a ex33u 1999 machine.... the wattage is unknown..

the size I have given above..

the external material is like Bakelite but may not be..

the connections are not important as i can change either end to suit

the old coil had an outer cover that held it in place but again I am happy to hold it inplace with a zip tie or tape as there is no load on the coil..

the OEM part number is 0685606...

 

Hi;

   Have you tryed taking the coil wire assembly to a motor rewinder premisses. They could remove the old wire, check the wire size and replace the winding with new wire. It may cost a couple of $$, but would be a lot cheaper than a replacement. Most likely removing the old wire and winding on new wire would not be a problem, and would most likely done on a lathe.Some thing to think about.

-- Edited by valiant81 on Tuesday 3rd of June 2014 07:41:40 PM

HI Bob
Now that the old coil is stuffed it is near imposible to obtain any info from it regarding its power[watts]

If it could be dismantled then as suggested a rewind could be the way to g,o but one would need to get the wire dia, strip off the old winding & THEN REWIND UNTIL FULL TO THE SAME LEVEL AS THE OLS WINDING

Without seeing the full assembly I cannot offer any comment on the pull in -pull out problem
But it does not matter which way the Coil is wound as changing the feeds around does simply correct that!
but again that will only have an effect if the piston rod is a permanent magnet
If a nonmagenetised piston it will simply attempt to pull into the coil
what can effect the direction of pull is the actual location of the piston in the coil in the unpowered position

It will either try to centralise itself or if the coil has a steel end piece on the top of the tube pull up to that.
If you can post some pics of the actual piston & actuator we may be able to see why that is not so.


Other than that, any 12V coil that is phsically near the same size ,in all aspects, & is continuosly rated should be ok .


PeterQ

Baz421 wrote:

---

Hi Bob

 

you may be able to buy from overseas if you can't get it rewound (assuming it is rewindable that is).

found these sites, some have tech diag to ensure it's the same valve body (I hope)

http://777parts.net/johndeere/0685606-solenoid/p179548.html

http://en.technikexpert.com/HITACHI-0685606-SOLENOID_detail_1949343.html

http://cn.777parts.net/hitachi/0685606-SOLENOID/p8431.html

might be useful

Cheers Baz

---

 Hi Baz, you are a better searcher than me they are all the correct solenoid and thats the body they fit into mate...

Now all I have to do is find out if I can get a price and buy one IF it isn't to expensive an help in that direction would also be appreciated..

PeterQ. Thanks for the extra details on why it pushes the pin out..

Also thanks to everyone that has tried to help, I said to a mate that came to help get to the bottom of the problem and then get it going by making a longer pin to make it work without the solenoid working that I would ask for help on this forum... he laughed and said good luck.... not knowing we have lots of experience between us all and sure enough the answer has been found and the mystery of solenoids explained..

Holy Solenoids Batman!

The Grey Nomad Team to the rescue again.

Hope it all works in your favour Bob.

DeBe wrote:

---

This is only a guess Bob. For the solenoid to push a pin, the armature is probably similar as ive drawn it. If this is so then all you need to find is a solenoid of the same dimensions & it should work.

---

 

 

HI

Yes, DeBe

That illustrates a plunger that will pull DOWN into the coil & will not be polarity sensitive..

AS can be seen the actual plunger is above the windings & will just attempt to centralise itself within the COIL length

That is a special arrangement & most off the shelf solenoid will not be designed that way

Bob ,  from the pic you show, it seems the pin is much smaller thah the coil ID

, I think you will find the the actual plunger is still inside  the coil .

AT the very top, would be it's normal open position

If you can get it out & it is the same  clearance od with the new coil , it may work Ok

Actually any soft iron round steel could still work.[soften by heating to red hot, then slooooDwly cool]D

Depends on how much you want to experiment

PeterQ

 

Remembering that all selonoids work on the same principle, the plunger will be pulled into the centre of the coil, .that does not matter what polarity the source or if it is AC or DC 

PeterQ

 

 

-- Edited by oldtrack123 on Wednesday 4th of June 2014 10:45:54 AM

-- Edited by oldtrack123 on Wednesday 4th of June 2014 11:03:39 AM

oldbobsbus wrote:

---

Hi Peter..

It is a 12v system and it is a ex33u 1999 machine.... the wattage is unknown..

the size I have given above..

the external material is like Bakelite but may not be..

the connections are not important as i can change either end to suit

the old coil had an outer cover that held it in place but again I am happy to hold it inplace with a zip tie or tape as there is no load on the coil..

the OEM part number is 0685606...

 

---

 Hi Bob,

well the level of help offered has been great, and very informative. Thanks to PeterQ and Debe, I now know why some solenoids push, and others pull. The excellent search done by Baz has given some leads on getting a new solenoid through the OEM number system.

If you can buy it direct from overseas and wait a week for it to arrive, the price should be about 1/3 what you have been quoted. In the hydraulics industry standard markups on imported goods is around 300 - 400%. Highway robbery, but if they all do it, and you want the item, you have very little choice.

 

I was going to try and get to the actual manufacturer of the valve, because the valves, pumps, etc, used on this type of machinery are normally made by specialist hydraulic manufacturers such as Bosch Rexroth, Linde, Eaton etc.

If you would still like for me to do that, I would need any numbers off the valve block, and would then follow up with valve suppliers such as Sun, Sterling, Oil Control, etc. 

Wish I was there. With the valve in my hands I could take enough measurements to order a new one off the shelf in Australia.

 

Let me know how you get on.

 

Peter K.

Bob, the mounting flange arrangement is rather unique.
I will see what I can find with that type of mounting.

Keep going with your enquiries as well and we will see what happens.

Peter K

PJK wrote:

---

Bob, the mounting flange arrangement is rather unique.
I will see what I can find with that type of mounting.

Keep going with your enquiries as well and we will see what happens.

Peter K

---

Hey Peter

seeing you are in the industry there may be another way to tackle this. There are MANY MANY Chinese manufacturing companies n the web that only manufacture solenoids BUT they must number their own products separately, as I couldn't cross reference the OEM part number to any they make.

maybe you have access to some cross referencing info??? Just a thought.

Cheers Baz 

Bob  at the wreckers in Oz

http://www.marketbook.com.au/listingsdetail/detail.aspx?OHID=10012203&LP=MAT

the above was found here, some in Oz some overseas

http://www.machinerytrader.com/list/partssearch.aspx?Manu=HITACHI

HI Bob
Looking at your last pics ,it seems you still have a smilar soloniod on the unit
Can you check the resistance of that coil & compare it to the new one?
If it is near the same, that is a fair indication of being the same power.
The other thing is are they the same length?
When I looked at you first set of pics I thought the lump on the top of the original was part of the coil assemby ,I now see it actually an extension of the actuator sealed assembly.
If your replacement is longer than the oriiginal , the action on the plunger will not be the same , remember what I said about the plunger centralising in the selonoid
Equaly so if it is shorter you may have to raise the coil to get correct operation for max pull

MAX pull or push is obtained just in the last few millimetres of travel[to the centre

I would expect the actual movement of the pin would be relatively short ?

PeterQ

WoooooooHoooooooo, as it is a bit cold and overcast here today I decided to bring the machine into the workshop and have a go at fitting the new solenoid...

I put it on upside down and connected it up to the plug and WooooHoooo it worked perfectly first try so apart from giving it a days work to test the coils ability to stay stimulated for a prolonged time all is now good...

As you can see I have zip tied it in place and sealed the plug connection with silicone in such a manner as to be able to pull it apart later if need be without damaging the wires..

A couple of pix of the new unit in place and one showing where it is and also one with all the covers in place which is why it was sooo friggen hard to find in the first place..

 

Again a BIG THANK YOU to everyone that helped and as I said before if any of you are up here near Grafton feel free to drop in and have a yarn for a day or so as there is plenty of room here on the farm..

My phone number can be found on the Country Music website below if ya want to call and say G'Day anytime..