David Brown 880 Selectamatic Hydraulic Problem
Hi there,
I have recently purchased a David brown 880-selectamatic 1966 white version. I have a fair bit of experience with rebuilding tractors but this has baffled me, can anyone help me to solve this problem, I have placed a post knocker onto the external hydraulic pipe system on the back of the tractor, but once all the correct valves have been opened and the rear hand leaver dial aimed to external t.c.u. nothing happens apart from a slight twitch from the pipe. The oil admitedly was slightly creamy as water must have entered from running down the gear sticks, so oil and filters have been changed, another David brown tractor has easily lifted the weight on the post knocker, so that is working ok, and I have lifted a tipper trailer with the external hydraulics ok but with a slow return. The pump pressure has been checked, and with some revs read 1600, so, what do you think the next area to check is,
Thanks,
Ken Coppice
Hi Ken,
Obviously the hydraulics do work because you have tipped a trailer. Could it be that the hydraulic couplings are not opening each other???? Try new couplings or hard piping the post knocker to the tractor to see if that solves the problem. I know this doesn’t seem like a particularly technical suggestion, but it just may be a simple thing like this that is causing you problems.
Regards,
Steve VTE
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The quadrant leaver needs to be held in select or it won’t be in constant pumping mode. Some tractors have a pin on the leaver and a catch on the quadrant, for loaders or a hydraulic mower. if you don’t have a catch tie it back. The hydraulics are in TUC mode unless the leaver is held in select. By the way make sure that the leaver is in select when you change hydraulic modes if you try to force it you’ll break the fork inside the casting and thats a big job to get at it.
Pressure should be about 2200 psi min. Could be the pump or main relief valve. MRV is adjustable via shims. If the oil is in the state you describe then time for oil and filter change. If slow to return was dump valve open?
I have a 1974 David Brown with a case loader. I recently ran it low on hydraulic oil. I added and then the loader started acting funny. When I go to lift it goes down instead,it almost stalls the tractor. Any solutions? Air lock maybe?
Have you moved one of the controls by mistake??
Steve.
Hi,
Anyone got any idea how a DB 770 hydraulics work. Recently bought this tractor – which was parked up for some time. When started – lifts go up, have no idea how to get them down – levers dont do anything to control the lifts. There’s a knob beside the lever (on differential pedal side), that turns, what does this do? Is the hydraulic pump in the back end of these? Christ – why cant they just be like the MF35’s! Grrrrrrrr….
880 white david brown have had it for 30 years never does much but last year and this year took it to moss to bring out turf to road with linkbox . once warmed up lift performs poorly having to really rev engine to keep lift up mabye only 8 bags of turf on linkbox . i changed the oil. old oil like new . i put in hyd type oil . can any one tell me the type of oil and where a filter may be or would there be something else wrong . i have been playing about with levers to put into constant pump but no better.
Midlands I’m having the same problem. Let me know if you find the solution.
BUCS
Des…. Hydraulic type oil is too thin for the hydraulics… not sure of the number of the correct oil but the same grade of oil as whats in the engine is the correct grade – should find the hydraulics work better after that
Midlands, welcome to the world of david brown hydraulics – sounds as if theres a stuck valve somewhere- the knob to the right of the seat near the diff lock pedal controls the speed of drop of the hydraulic arms- the hydraulic pump is located in the rear of the tractor- you’ll need to remove the pto housing and its right in front of you (if a long shaft comes out along with housing shove it back in when you draw the housing off far enough to grab it )
First thing I can think of is to check that the cable that controls draft control on the top link bracket isnt seized . 2nd thing would be to remove the oval plate (on the right hand side behind the quadrant lever on the top ) (there may be a dump valve through the plate (remove it and u should see 2 hydraulic valves- take the caps off to expose them (I suspect one of these valves will be stuck)CAREFULLY REMOVE THE CONED VALVEs – DONT DROP IT IT’LL FALL TO THE BOTTOM OF THE TRANSMISSION CASTING LOL ) clean it with a dust free cloth and put them back in- this may help
there should be a small round plate at the drain plug on the gearbox. remove this and there is a mesh filter , it just pulls down, clean this well( if you remove the o-ring from the top and pour a drop of petrol on and light it , it will be fairly clean, just tap on a hard surface and blow out with an airline) after fill the gearbox with 5 gall of diesel , start it up and use the lift until the diesel gets around the valves and cleans any grit out , drain and refill with new oil
I have a David Brown 885. I changed the trans/hydraulic oil and filter and cleaned the mesh type screen. I found the fill plug for that to the left of the steering column. I need to know what the plugs on each side of the seat are for. If they are for fluid, what type? The one by the left side of the seat seems dry. The one by the right side of the seat, when checking with a screw driver has a small amount of lube of some kind. I do not have a manual of any kind. The rear hydraulics work fine now, but I am concerned about the plugs by the seat. Any help would be appreciated. Ken
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