Siroma 204E (Jinma?) hydraulics questions

RonMar · Jun 13, 2013

EE_Bota said:
Per the schematic, closing any of the valves, including the variable flow control valve is just a nicety to keep from cycling the lift every time you dump the trailer.

Actually it is a requirement on the 200 series. There is a link from the 3PH lift arm to the control lever. If you don't close the speed reg valve, when you try and dump the trailer with the 3PH control, the arms will come up, and that lever will kick the control valve back into neutral before the dump trailer will move an inch...

EE_Bota · Jun 14, 2013

RonMar said:
Actually it is a requirement on the 200 series. There is a link from the 3PH lift arm to the control lever. If you don't close the speed reg valve, when you try and dump the trailer with the 3PH control, the arms will come up, and that lever will kick the control valve back into neutral before the dump trailer will move an inch...

Good point, and I certainly believe you. I just can't see that in the schematic.

The arms are supposed to be down on the 304 too. It has position and draft control, so I'm sure making them stay down is a help.

I wish I had "known correct" hydraulic schematics for my tractor and some of the others.

EE_Bota · Jun 14, 2013

While doing a search for a better schematic, I found this written by Ron, and it tells chapter and verse about that valve. Good write up, Ron.

http://www.tractorbynet.com/forums/chinese-tractors/62435-caution-jinma-284-hydraulic-failure.html

dwk789 · Jun 17, 2013

Hello All,
First things. I've now got my trailer going up AND down.

I phoned the dealer before I went to have a bespoke pipe made up. As it turns out the valves I have at the rear for the double acting cyclinder are standard and not an added option. However the pipe I required was standard on a different model which would bolt straight on to my control valve (as shown in Rons picture). At 32 UKP + delivery + tax I bought & fitted it.
One thing I finally figured out. At first I couldn't understand how shutting the the valve that restricts the return fluid (down stroke) helped because the fluid could still send it up. Idiot. Then I realised if the return oil can't get out of the other side of the piston then the cylinder can't extend. Got there eventually!
Circle D. Thanks for that. The adding a seperate return was plan B if I couldn't get the above to work. In so far as switching the engine off, I'd had this suggested before but couldn't get it to work. Never mind all's well that ends well.

Again, thanks to all on the forum.