885 Dead Hydraulics

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ctomlin
Posts: 3
Joined: Thu Jun 13, 2019 2:58 pm
Location: United Kingdom

885 Dead Hydraulics

Post by ctomlin » Mon Jul 15, 2019 11:21 am

Hi All,
I have a bit of a battered 885, engine is running nicely, but no hydraulics at all. The tractor was sitting for a few years before I bought it. I rescued it from a garden and brought home. The gearbox/hydraulic oil was in a shocking state, completely emulsified and when I drained it out, the filter had disintegrated. As the the oil drained from the rear plug, the only way I can describe what came out was it looked like my tractor was having a Sh1t! So, not good! I rinsed the system twice with 20L of diesel running it for 5 min or so and the PTO as well, second time without the filter, the diesel that came out looked much less contaminated. I replaced the filter, cleaned the mesh filter with petrol and replaced, then refilled with Oil.

I ran it with the quadrant in the lowered, as per the manual for a bit, 5 min or so but no joy. I checked the oil coming from the top of the spool valve, it looked like fresh oil with no bubbles.

Now this is where things go badly wrong and I am deep down the rabbit hole..!

Reading through the workshop manual it suggests bleeding the system, in particular the Ram. So after lots of WD40 I tried to loosen off the bleed nipple, but it is difficult to get to as the selector lever assembly partly restricts access. I could get the open end of the spanner on, but the bleed nipple wouldn't budge and I could feel the flats of it rounding off, so I stopped. More WD40... I decided to loosen off the selector assembly to allow me to get the ring end of the spanner on to loosen the nipple, but although it did move slightly, it still wasn't great. So, I decided to completely remove the selector assembly so I could get a socket on it. More WD40... 30 min wait... got the socket on only to completely round off the flats, I now suspect the nipple to made from chocolate - or does it have a reversed thread?!

It now gets really bad...
I looked witheringly at the situation and decided one way or another it need to come out, so I got a stud extractor to it - I got nowhere other than destroying the nipple.

So now I have a few questions:
1. can I get a new one?!!
2. Is it held in place from the inside, am I going to have to strip the ram to get it replaced?
3. Any more ideas why I have dead hydraulics in the first place?
4. Is there a better manual than the one I downloaded from Best manuals?

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ollek
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Location: South West Finland

Re: 885 Dead Hydraulics

Post by ollek » Mon Jul 15, 2019 12:26 pm

What are you referring to when you wrote "I checked the oil coming from the top of the spool valve"? There is no oil coming from the top of the spool valve, you must be talking about something else than the spool valve. Air in the lift cylinder is not the reason for no lift. Bleeding the lift cylinder is not the solution if you have no lift. Air in the lift cylinder will give "spongy" hitch when the linkage is lifted up. Reading about the state of the oil, I would suggest that the problem is sticking and dirty by-pass and hold valves. You also wrote " second time without the filter". In doing this you have introduced even more dirt into the system, never run the engine without the hydraulic suction filter and screen in place. Please read the following in order to learn something about the Selectamatic system. The link also gives some hints in fault finding the system and informs of all adjustments tat have to be made if the system is striped down or any parts are removed. http://dbtc.co.uk/index.php/information ... lic-system The following link takes you to a workshop manual for hydrostatic steering and Selectamatic hydraulics. https://drive.google.com/drive/folders/ ... VVrOVJvbmM I would recommend not to do anything else at this stage than cleaning the by-pass and hold valves and checking that the spool valve is moving. Please be aware of that all workshop manuals are written by experts and meant to be used by individuals that have a basic knowledge of the hydraulic system.

ctomlin
Posts: 3
Joined: Thu Jun 13, 2019 2:58 pm
Location: United Kingdom

Re: 885 Dead Hydraulics

Post by ctomlin » Mon Jul 15, 2019 3:59 pm

Hi,
Thanks for the reply. I understand your comment about needing a basic knowledge of the system, but when you've never owned or operated one it's always hard to sift through the information available to find the correct info! It was reading on various forums that made me think maybe the system needed to be bled, assuming the worst case condition is it didn't need to be bled and the fault was elsewhere I didn't really think I had much to lose!

On reflection, looking again at the notes you linked to, I do not seem to have the bridge piece? My tractor is a 885N, to be honest much of mine does not look like the pictures I have seen in the manual I have or in the copy of the publication you sent me the link to! The two things I do have are the valve sticking out with a knurled top. This is rusted solid, I think is the hold relief valve, used to allow the fluid to be dumped back allowing external stuff like a tipping trailer to drop quicker - is that correct? On removal I could see the oil inside was still the old emulsified oil. Opening this while turning the engine, I do not get any oil coming out. This valve goes through a cover, which when the cover is removed there is another flat bladed screw top, this I mistakenly thought was the spool valve, but looking again I guess it is the Hold Valve? When I loosened this off while turning the engine, clean looking oil flowed out with no bubbles. With the engine stationary, no oil came out.

This is really as far as I got before I disappear down the rabbit hole over bleeding the ram. Interestingly the three way valve, which impedes access to the Ram bleed, when removed also only had the old emulsified oil, so no new oil has got here - is this correct?

Can I buy a new Ram bleed nipple anywhere? Also, I assume I should be able to remove it by screwing it out in the normal way? I am assuming for now this one is rusted or otherwise in place and will have to drill it out?
Cheers Colin

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ollek
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Location: South West Finland

Re: 885 Dead Hydraulics

Post by ollek » Mon Jul 15, 2019 8:14 pm

The hold valve is in the top of the valve chest and the dump valve is on top of the hold valve. It is the dump valve that goes trough a cover that helps to get the tip down quicker, not the hold valve. You will have to remove the dump valve and the cover in order to get to the two plugs for the by-pass and the hold valve and also to see the top of the spool valve. The valve has two nuts on it, do not touch these nuts, it will mess up the adjustment of the valve. You did not tell that the tractor is a narrow (N) model, and quite correct, there is no bridge piece in a narrow tractor. If you remove the by-pass valve plunger and keep the hold valve plunger untouched, you should get oil out from the drilling for the valve when you crank the engine (do not start). If not, then you can have a pump problem or a broken pipe between the pump and the valve chest.

Gard
Posts: 256
Joined: Sun Apr 06, 2008 2:25 pm
Location: Fairfax Vermont USA

Re: 885 Dead Hydraulics

Post by Gard » Wed Jul 17, 2019 12:53 pm

I know the hydraulic system on your tractor is a lot different from my 900 but the state of the oil and filter when I got it was the same. I think flushing with clean diesel was a good start but I ended up removing cleaning and replacing every valve on the tractor including the ones attached to the pump before getting everything working. Just keep working away at it one system at a time.

For the stuck bleeder I would try welding a lump onto it that you can grab with locking pliers. The localized heating and cooling will most likely loosen it up. I am sure a new or used one can be found or fabricated. I think there is a seating or sealing surface under the bleeder that would need to be resurfaced if you end up having to drill it out and go a little too deep.

Water most likely entered the system from the rubber boots on the transmission shift levers so add new boots to the list.

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db2d
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Location: Monmouthshire

Re: 885 Dead Hydraulics

Post by db2d » Wed Jul 17, 2019 4:39 pm

If the bleeder is not leaking I suggest leaving it as it is.

ctomlin
Posts: 3
Joined: Thu Jun 13, 2019 2:58 pm
Location: United Kingdom

Re: 885 Dead Hydraulics

Post by ctomlin » Wed Jul 17, 2019 10:48 pm

Thanks for the replies. I tried again to get the bleed nipple off, long story short, it sheared! Bum!

I investigated further the hydrolics. I removed the right hand ramshaft cover with the engine running to see a plume of oil gushing from the far right side. It did not matter where the quadrant was the flow rate didn't seem to change. I loosened off the bypass valve cap a quarter turn to see a good flow of oil. I loosened and removed the dump valve from hold valve, there was a slow flow of oil.

I inspected the bypass valve, the needle was a bit bent, I straightened it. I removed the sleeve assembly but did not remove the brass restrictor I just blew it through with my compressor.

I checked the hold valve, I found the restrictor with the three holes, but no ball bearing?!
Reading the notes on the web page here, it suggests checking the movement of the spool valve. I guess the is the two nuts on top of each other? If so these don't move when I move the quadrant engine on or off. The notes suggest I remove the whole assmebly and check the movement of the spool valve, but I can't find any background how to remove it!

Any help greatly appreciated!
Colin

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ollek
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Location: South West Finland

Re: 885 Dead Hydraulics

Post by ollek » Thu Jul 18, 2019 5:42 am

The spool valve is most likely stuck in the up position if it does not move and there is a oil stream from the right hand side of the valve chest. Try to pry the spool valve up and push it down manually a few times if it does not move when you move the main control lever. There are some pictures in one of the ink I have sent earlier and there you can see the spool valve with its two nuts. Have you had the by-pass and hold valves out from the valve chest? You must remove the valve plungers using a wooden stick pushed into the valves and make sure that they are moving in the drillings. I have provided the workshop manual earlier and you can read it by clicking on the second link in one of my posts. The manual shows all valves and the parts in conjunction with the valves. The manual also gives information's about removing the valve chest as well as the adjustments that have to be made. Please, read the information's you have been presented with. db2d tried to prevent further damages when he wrote "!If the bleeder is not leaking I suggest leaving it as it is". You also have to prepare for a bigger repair, if loosening the by-pass valve, hold valve and spool valve will not fix the problem with no lift. This is because of all the dirt and water that has find its way into the valve chest.

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