953C Mag Coil.

[tctractors]

I am working on a shovel with low hydraulic pressure (1200psi at rod end) this is useing the test port on the tank, the seals are knackered on the MPRV on the block with the test port, but what does the mag coil just below the R.V do, it does magnetize when the engine is running, but it makes no odds if I remove the coil from its pillar or leave it on the arms still lift (slowly) I would think that the hydraulic pressure is around the same as a 953B etc, to put a flow meter test in play is a bit of a pig on this bird for me??? so its fix the seals on the relief valve then if things are still crap whip out the implement pump, any help would be great???

tctractors

 

[Bob/Ont]

Hi TC, just need to get on the same page here. You have a 53 with low hyd power? You have a gauge into the pump outlet? Load up lift and then tilt both directions at low idle then full throttle come on back with readings you get. Does the pump make much noise under load?
Later Bob

 

[Cmark]

The solenoid was fitted to the early machines. Discontinued on the later ones.

It gives two pressure relief settings. High setting when 24v to the coil. From memory, I think it goes high in bucket crowd.

You can strip the relief valve cartridge to check for crap stuck under the seat, but don't be surprised if it turns out to be the pump. I've changed out maybe three or four.

The pump is a vickers cartridge, but I've never had any luck getting one aftermarket. The last one I bought from Cat had to come out of Morton.

As you know, Cat's parts system is second to none, but availability of parts for the track loaders is noticeably poor from the southern hemisphere centre in Singapore. Maybe you'll have better luck with Grimbergen?

 

[tctractors]

Thank you Cmark and Bob for your comments, I tend to think its the pump done in myself, but the seals on the PRV are a might damaged so its to be sorted first, on the pressure thing all I get is 1200 psi on the bucket and frame so its not an issue with any 1 system control, the test point is on the front of the tank that I have used, is there a strainer/mesh in the tank on the oil supply to pump side? I also se the plumbing gets a bit tricky under the implement pump shareing things with other pumps, I did have a pamphlet thing that listed Vickers cartridges to CAT part No's but this Chariot would be a bit to new to find in it, the tank looks some game to strip if its needing a clean out.

 

[Cmark]

Before you start to pull the implement pump, I'd advise you to run the tractor up onto some sleepers or simillar. If you've got a pit handy, even better.

Once you're under there, you'll find a stack-up of suction/return lines bolted to the bottom of the pump with four bolts about a foot long. Not hard to get to but plenty messy and plenty of O rings to replace when its reassembled. You'll also notice an aluminium tube thingy. This contains a screen for the (I think) travel motors case drain. It's worth cleaning this out while you're at it. The rest of the work is through the cab floor. Remove a couple of steel lines for access to the pump mounting bolts, attach some sort of hoist to the cab roof and it'll come out OK.

There is a screen in the tank but its pretty coarse. If you decide the hyd tank needs a clean, remove the fuel tank instead and you can take the side off the hyd tank no problem.

As always, good luck.

 

[tctractors]

Cmark, firstly may I thank you for your well scripted reply, Today I poped up to Finning HQ Parts Dept to sort a few items on this Shovel, Rodger served me he is very shortly to retire, so you know you are getting the best of the best helping you sorting out the "dilema" he always makes small work of helping with parts print off's etc that you can keep to help things along, Rodger is the best advert for a man that loves to be helpfull in any parts location, anyhow the PRV seals are a bit knackered, the seal kit is around £100 so they where ordered plus the seal kit for that Mag Valve at around £4, the implement pump cartridge is around £1'200 mark so i Have that not on order but know its Ex Belgum (Grimbergen) so its realy only next day away if needed,I did drop out the Belly plate and have a peep at the oil feed situation, also whey up the effort to get inside the Hydraulic Tank, as you said its Fuel tank out on this job as it looks a right dog to tackle that heap of pipes, I would have liked to have done a flow meter test but the pipe work is just to tricky without a spend out on a bit of pipe work, again thank you for your trouble I will get a few pic's of my antics.

 

[tctractors]

Just thought I would post up the "Events" on this chariot, the Shovel has a good few hours on the meter so after replacing the seals on the MPRV and the coil spool with no improvement to the beasts pressure reading, I crawled under the tractor and set free the guarding, and removed the Implement pump (Mistake) stripped down the pump to find its innards like a new born baby? so refitted the pump and then managed to cadge (get for nowt) a pair of 1" bore High pressure pipes to hook up my flow meter and do a proper pump test for flow and pressure, the pump was working crack on, I should have done this in the very start as now my Customer looks at me as a messer(or something very close to it???with a W) anyhow now I know its something inside the Tank thats failed, the fuel tank is filled to the top so there is a bit of work now attached to the beast to get it in bits, credit to CAT that Hydraulic Tank is some pig to get into, any Ideas on what I might find failed? I will post some pic's asap.

tctractors

 

[Cmark]

That system is pretty basic. To my knowledge, there's nothing in the tank to affect all the circuits together, only line reliefs in there.

Did you strip the MR? I wouldn't be busting the tank open before I'd eliminated it as the cause.

If you'd like to PM me your email address, I can send you a copy of the service letter for the update to the later type valve for your delight and entertainment.....

 

[tctractors]

Cmark, thank you for showing an interest in my "Drama's" I did strip the Main relief down to check things looked as ought to be, the Serial No of this Chariot is 2ZN02679, its a 1999 build Shovel but its in realy stong condition with running gear in the 80% area with very good un-damaged outlook, its hell of a tidy Shovel compared to the usual 953/963's I get to work on its a bit of a Gem.

tctractors

 

[tctractors]

Well after messing about with this low pressure thing on the implement pump, I thought I would just test a few other oil lines and do my homework on the pumps, this is to check the charge and pilot pressure, so with 3 gauges hooked up I fired the motor into life to see instant Magic show up on the clocks including the implement pressure heading past the 3 1/2 large when the jaw spool (4x1) was tweaked, Cmark had sent me detail changes involving the MPRV that I will be sorting with Finning (CAT) all I can think the fault was involves that PRV, worst thing being the owner was looking at the gauges with me at the time perhapse I should have unbolted the valve housing off the side of the tank???? anyhow it work A1 and the shovel runs real sharp so thanks for all the help.

tctractors