Urgent help required with D1850FD hydraulic control valve

Ally · Nov 7, 2008

Hi, I'm new to this forum and you've got no idea what a relief it is to discover you guys! I live in Australia, have a Mitsubishi D1850FD (i think) gray market tractor, no manual (reckon that won't surprise anyone), have problems with 3PT linkage not lifting and DESPERATELY NEED ADVICE about how to remove the seat on the hydraulic control valve. I have an exploded diagram of a similar control valve which is removed with an allen key (or hexagon wrench as you guys might call it). Mine, however, just has almighty slot that would fit a giant flathead screwdriver. Needless to say, I've tried everything to remove this seat but just can't. I must have the case reassembled this weekend so PLEASE CAN ANYONE HELP???

Ally · Nov 8, 2008

I made a tool and got it undone. Problem is now, that once its all back together and I push the plate and let it spring back so I can set the distance between the body of the valve and the plate....... well, if I push and let it spring back, then I have one measurement...but if I PULL and let it spring back then I have an even bigger measurement. I can't for the life of me figure out why this is happening. Everything is lubed up and the springs appear fine. Also, the air tests (where you insert air into the unloader valve) are failing despite many adjustments. Any ideas anyone??

mit · Nov 10, 2008

hi ally the way i understand the 3 point hitch is like this.oil comes from the resovour passing through a screen which is in the resovour.the pump pumps the oil thru a pressure relief valve to the control valve.when you move the control lever to raise the hitch.the control valve allows oil to go to the lift piston which forces the arms to rise. the arms will rise to the point depending on the setting of the control lever.at this point fluid will be bypassed from lift cylinder and go back to the resorvour.the only adjustment is done to the linkage between the valve and the lever.i remember i had to hold a nut on the control valve in a vice the nut had a hole on it.i used a wrench on the control valve body and turn counter clockwise.

Ally · Nov 13, 2008

thanks again mit for your help. taking the top off the hydraulic case was a great learning experience in hydraulics for me as i was able to work out what went where and how it all worked. not as complicated as i thought it would be

i had already removed the big nut with the hole in it. in fact, in my usual style, i had dismantled everything (i did have an exploded diagram to guide me). the diagram had the settings listed but i was having problems with the way the backplate was springing back to the valve body. anyway i fudged my way through and i've managed to get things ALMOST back to normal

not bad for a girl! hahaha..

mit · Nov 13, 2008

very nice ally. now post some pics for us to see that work horse tilling the dirt.i just installed a block frost plug heater on mine. waiting for it to get colder to see how well it works.so far it starts nicely at 35 degrees f.

Ally · Nov 16, 2008

what is a block frost plug heater? is it to replace the glow plug? i am unaware of your climatic conditions where you are. do you need the block frost plug heater in your winters over there? sorry for sounding so niave

Ally · Nov 16, 2008

sorry mit, can't post photos. there's no-one to take them while i'm working

PILOON · Nov 16, 2008

Ally said:
what is a block frost plug heater? is it to replace the glow plug? i am unaware of your climatic conditions where you are. do you need the block frost plug heater in your winters over there? sorry for sounding so niave

When temp is at freezing or below, fuel does not ignite well and simply glow plugs are not enough, hence the common solution is the 'block heater'.
Other methods do exist such as inline hose installed heaters as well as a dipstick heater element.
On smaller engines the most popular is the frost plug method. One simply pries out the frost plug and replaces it with an o-ring sealed heater element.
Large engines will generally use an inline heater assy that is spliced into a coolant hose line.
In Canada, forget starting a fuel powered engine without an engine preheater.
Generally about 1 hour of preheat is needed.
About 500 watts is what one wants on smaller engines.

I notice that on some newer design engines the manufacturers actually provide a threaded socket to accept block heaters; guess that negates having to drain coolant to install/service the heater.

oliver28472 · Nov 17, 2008

And your frost plug will be a small bowl shaped metal disc on the side of your engine block. There may be one near your oil filter. It should be about 45 mm diameter. Mit put one in his recently. You can search for that thread and get what you need.

mit · Nov 18, 2008

Its ok Ally.there is no rush for pics.i think australia is pretty warm so you may not need a block heater.sounds like you r all alone in a remote part of down under.b careful out there dont get attacked by a kangaroo.in all honesty you did an excellent job of fixing that 3 point.for a gal u get ten stars.keep up the good work.