MCconnell Marc 425 XL

[RealMav]

Hi ,I have a MCconnell Marc 425 XL , I think it is built by Jinma and nearly the same as Jinma 284. The tph has issues lifting when it feels like it, Also today after using fel for awhile the engine started sputtering and smoking when revved up. then all at once it blew oil out the breather on the right side of the engine. Shut it down quick. oil was over filled. Drained out more than 2 gallons filled up with 6 liters and seems fine now. Coollant level is normal , Fuel tank still full, Maybe Hydro fluid in oil, The fel and steering is slow to not working when cold. I need to get this tractor working proper.I need a new oil filter, and the filter under seat in hydro sump.Would like info and ideas on getting this tractor working.Thanks.
ps The hydro fluid looks clean, The hydro oil in the rear sump for tph looks cloudy and aerated, Are there seperate pumps and sumps for thp and fel ,steering? The only time the tph worked was when I filled it and then it bubbled out arond lift arms and plug.

 

[quicksandfarmer]

Sounds like a Jinma. Jinma's have a tendency to blow out the seal on the hydraulic pump, which results in hydraulic fluid entering the engine sump. Sounds like that is what happened to you. The usual cause is restriction in the hydraulic lines, there is no pressure relief and if the pressure is allowed to get too high the pump suffers.

The most common cause is the quick disconnects for the FEL coming apart.

You need to find the cause of the obstruction. Then you need to find out if your pump is blown or just the seal. Then the hydraulic fluid level. Both the steering and the FEL rely on the hydraulic pump so once you're hydraulics are working those should shape up. In cold weather the hydraulics on mine tend to be slow until the fluid warms up a little.

The balky tph lift cylinder is a common Jinma problem and probably not related to everything else, it's usually fixed with a new seal.

 

[Diamondpilot]

It's the same old issue. Get rid of the quick connect fittings and replace with swivels. Then fix the pump seal, change engine oil and hydraulic fluid with filters.

Chris

 

[RealMav]

It's the same old issue. Get rid of the quick connect fittings and replace with swivels. Then fix the pump seal, change engine oil and hydraulic fluid with filters.

Chris

Ok Chris , are you saying the QD 's are the restriction even if none came off or apart? thanks Ric

 

[Diamondpilot]

Ok Chris , are you saying the QD 's are the restriction even if none came off or apart? thanks Ric

Yes, they can be restrictive internally. The Chinese QC leave a lot to be desired.

Chris

 

[greg_g]

The use of Teflon tape to seal hydraulic fittings is a common cause of QD blockage. Bits of it that got cut off while rethreading/tightening fittings flow in the circuit, accumulating at choke points like valves and QDs. Thread sealing compound (or liquid Teflon) is the preferred method.

//greg//

 

[RealMav]

Hi all, did a bad thing, trouble shooting the tph I took a plug out of the lift lever control ,not knowing what was under it out popped a spring and maybe more small parts,I have been unable to find them if they came out in the snow. They would be a ball 5v part number gb/t308-89-5v and a spring seat part number 14fp.57.118. from my book on this tractor. Can I order just these parts or do I need the whole control? I auctually did this before the overfilled engine oil issue. could they be related? Still need to remove pump and replace front seal. And figure a cure for relief valve.It was warmer out today so I cleaned out a spot under cover for the tractor and moved it . the loader and tph worked and now its under where I can work on it. Just where to start? Thanks for all help and tips. Ric

 

[RealMav]

I traced out all of the hydr lines and find a line coming out of the spool thru byd port and one out the output port . the one from out goes to a tee. the tee connects to two hoses .one goes to back of tractor to a qc that is connected to the hose back to byd. the other side of this tee goes to the divider valve,then out of divider one goes to steering and one goes to ift control, and a 4th goes to return to tank which is teed into return from steering. there is a relief valve in the spool but do no under stand where relieved pressure would go? the spool is feed directly from pump. thanks Ric
http://www.generalimp.com/sites/default/files/product-pdf/kelley_loaders_dl1000.pdf this is the loader I have.

 

[erj]

Ric, let's see if this helps any. Here are pictures showing the hydraulic flows on my Jinma.
1. I don't understand why you have a hose coming out of the Power Beyond port unless it was to mount a piece of equipment that is no longer attached.
2. When you say 'spool' are you meaning the FEL control valve?
3. Please clarify "one goes to ift control".
4. The FEL control valve contains spools that drive the cylinders to raise/lower/tilt the bucket.
5. On my control valve, when the relief valve is engaged the fluid escapes through the outlet port.

 

[RealMav]

I traced out all of the hydr lines and find a line coming out of the fel control valve thru byd port and one out the output port . the one from out goes to a tee. the tee connects to two hoses .one goes to back of tractor to a qc that is connected to the hose back to byd port. the other side of this tee goes to the diverter valve,then out of diverter one goes to steering and one goes to tph lift control, and a 3rd goes to return to tank which is teed into return from steering. there is a relief valve in the fel control valvel but do no under stand where relieved pressure would go? the fel control valve is feed directly from pump. thanks Ric
http://www.generalimp.com/sites/defa...ers_dl1000.pdf this is the loader I have.
erj ,mine is like yours except the byd port being connected back to the out port, I think there by disableing the relief valve in the fel control valve. I think it had a back hoe at one time. Today I un coupled the two lines and then it will not lift fel at all. New pump is on the way.With those quick disconnects undone do you think the pressure relief valve in the fel control valve will protect the pump.?
Take a close took at the photo in my first post and you can see the line out of byd port, then look by the back light a you can see the quick connects together. I have unconnected those two lines . It does not seem like they should be connected, Thanks Ric