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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,

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.


Steve VTE

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28 Responses to “David Brown 880 Selectamatic Hydraulic Problem”

  1. 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.

    • stephen B
  2. 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?

    • Matt
  3. 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?

    • ed
  4. Have you moved one of the controls by mistake??


    • Vintage Tractor Engineer
  5. 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….

    • Midlands
  6. 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.

    • des
  7. Midlands I’m having the same problem. Let me know if you find the solution.

    • BUCS
  8. 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 :-)

    • Jim McKechnie
  9. 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

    • gerry lavelle
  10. 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

    • Ken
  11. I have a david brown 885, I hooked a finger mower on today, when I was working on the finger mower the hydaulic arms would just drop slowly, and I have to give her a good rev to lift it back up but it still falls down even on high revs, can any one help me? please!!!!

    • Ifan
  12. Considering buying a David Brown 990. Can anyone tell me whether i can fit a hydraulic connector on the rear to operate my hay mower. ( five disc kuhn.) Just to operate ram to lift up and down. Cheers.

    • Roger Wood
  13. I have a 1970 David Brown 1200 selectamatic. The 3pt. hitch wont stay in potisition with the selector handle, its either all the way up or all the way down. What could this be.

    • Doug Fulton
  14. I have a 990 David Brown, the lift is really slow going up or down. What could be the problem? The tractor has set up for about a year.

  15. Ok guys from experience now after getting the manual and tearing it all apart here’s the skinny. If the tractor has been sitting( mine’s an 880 selectamatic) the seals are probably bad. The valves next to the seat have o-rings that need to be changed, and also there is a bleeder valve on the left side by your foot the o-ring will have to be changed. Here comes the fun stuff, you are going to have to remove the cable on the top of the pto then remove the bolts from the pto and pull it off. I have a canopy set up so I used a come along and a 2×4 to help me. The hydraulic pump will be underneath there also with a valve and o-ring. Then the lift arm where it is attached on either side in the rear has a large 1/4 around with a 2″ i.d. inside the collars holding the lift arm. Reassemble and change filters and fluid if needed. There are some minor adjustments as to lift and lower speeds, but unless the pump is bad this should fix the problem. It is usually those two large o-rings on the lift arm that are leaking according to the manual. I hope this helps!

    • George
  16. Έχω ένα DAVID BROWN 880 SELECTAMIC και δεν ξέρω πως δουλεύει το ευαίσθητο ( απομονονει το συμπλέκτη ή συκώνει τα υδραυλικά ) και ότι άλλο μπορείται να με βοηθήσετε από που παίρνει εντολή ?


  17. I have a 770 selectomatic, the lift arms are stuck up and won’t go back down. I have no experience with tractors. I inherited this one. Any suggestions?

    • d-rack
  18. Hello to you all having trouble with the most advanced Tractor for it time. I had a good laugh from all of you. I grew up on the seat of a David Brown back in the 1960 & 70s so to put you all in the picture with the controls. First with the select a matic system you have two leavers together, the big one is the main control & the smaller one is to pre set the height or depth & the round knob is for the speed of rise or fall rate. Good luck & let me know how you all go as I have a mate who built them.

    • Roger
  19. I am new to this and this is a two part question, Where do I find the serial number for a david brown 880? And where do i find a manual repair for it. Thanks for your assistance.

    • Juan
  20. The hydraulic pressure on a Case 1070 is good, but 3- point hitch won’t work if there is a load on. Works fine if not loaded. I have tried everything I know to do! Any ideas?

    • Jim York
  21. Juan…Ser No. is found on the chasis machined horizontal surface right and rear of the rad. If you’re in CANADA google Elmer Landman.

    • Scott
  22. Ken.

    I seem to be having a similar problem to you.

    See my post on DBTC.CO.UK.


    If you are still having the same issue, or have found a solution some input would be appreciated :)



    • David Tocker
  23. chris townsend i have a 880 david brown white version. where can i buy the mesh filter at the bottom of the transmission and what type of oil does it use if some one will help me with this i would greatly appreciate this.

    • chris townsend
  24. I have an eight eighty david brown white and brown version?I am tying to find a part store to buy a new mesh filter for under the transmission and what tipe of oil does it use please someone help!!!! my #904-259-9253.

    • chris townsend
  25. I have a David Brown 990 Selectamatic and her hydraulics are on and off. Was recommended to use CASTROL AGRI POWER PLUS, AGRI MP PLUS for engine transmission/diff and to refill hydraulic fluid. But she will lift sometimes but not others. Have had tractor for 22 years and has had many diesel line overhauls but the hydraulics have got me beat! I think I must have a leaking seal so when she’s been running hot for a while, i come home, drop hydraulics, let her cool and when i go to lift hydraulics again, dead flat! Any suggestions?

    • Michaela Holroyd
  26. I have a 990 David Brown with 3 forward gears and High and Low Range. The 3 point lift is working normal and will pickup anything attached to. The front end loader will lift but will not lift any thing much heaver than the lift arms and bucket empty.

    This happened very quickly. Brute strength one day and weak the next day.

    Any help appreciated.

    • Tom Wilt
  27. I have a 880 Selectamatic. The draft control cable broke and i replaced it with a new one. Tried to adjust it with the correct procedure. When I use my box blade now it won’t go down, it just scrapes the ground (soft) and doesn’t dig in as it did before.I can start it up and no mater what position I have the control lever in, the box blade come up. Also I would like to replace the o-rings and gaskets for the hydraulic pump. Does anyone know of a supplier to buy these from. Thank you for your help.

    • Mark Blaylock
  28. Well, I just stuck a brand spanking new pump om the 885 and NOTHING works! Whats happened? The only thing I can come up with is the pipe out of the pump is leaking on the inner side of the plate the pump bolts to. It pumped ok by hand, I tested it before the rear housing went back on, where is the oil ending up?

    • DB885
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