David Brown Hydraulics Problem

[Selectamatic]

My trusty 1494 has developed a hydraulic problem, and I'm stumped.

@john1594 has buggered off, he was an expert on these things...

Anyone else who knows the insides of a Selectamatic system like the back of their hand...?

 

[spark plug]

What’s the probloem? I’m not an expert but have overcome a number of issuers with my 1394.

 

[Exfarmer]

you may be best asking on the DBTC forum
but if you post the problem someone may help here
I can virtually certainly tell you the cause, but you probably know that already.

 

[farmer cen]

what’s the proplem @Selectamatic

 

[Stokes6368]

Sorry to jump into someone else's thread with my own problem, but I also have a David Brown hydraulic problem with a 1390, the hydraulics stop working.
I have changed both the back end oil and filter, and yes the previous stuff inside was probaly the worst I have ever seen, hydraulics were working but not well after this, and as the tractor isnt used much it was left like this for a year and on wanting to do some topping they got gradually weaker and stopped working all together,
Next changed the oil and filter again, the filter was pretty dirty, hydraulics didnt work so clean up that valve in the backend and they worked until i tried to use the tractor, and so assuming they had blocked up again I cleaned it once more and it was working for about 30 minutes before stopping once again.
I can only assume the system is so full of crap that is why that valve in the back end becomes blocked (although the last time it was not noticeably blocked) and the whole system needs flushing out really well.
Is it ok to use something like diesel mixed in with the oil to try and clean it out?
Is the problem possibly to be something else?

 

[multi power]

My trusty 1494 has developed a hydraulic problem, and I'm stumped.

@john1594 has buggered off, he was an expert on these things...

Anyone else who knows the insides of a Selectamatic system like the back of their hand...?

He is on Facebook

 

[Selectamatic]

Sorry everyone, I could not find the thread...!

The 1494 has a tandem pump, and an assister ram.

Suddenly, the plough would not lift, worked fine previously, got to the end of the furrow, no go.

There is plenty of oil in it, filter is clean, no major external leaks.

The arms will lift empty, but will not with a load on. They hold as the should, but have noticed that they drop a bit fast.

Some DB experts on facebook suggested it may be the dump valve, which made sense to me. Changed that for one I know works, no better.

It was working perfectly until I got to the end of the furrow, always has. Relief valve has pressure. Hydraulic top link from the spools works as it should, in both single and double pump setting.

I have been told what else it may be, but if anyone on here may have a suggestion, I'll let you go first.

 

[J 1177]

Sorry everyone, I could not find the thread...!

The 1494 has a tandem pump, and an assister ram.

Suddenly, the plough would not lift, worked fine previously, got to the end of the furrow, no go.

There is plenty of oil in it, filter is clean, no major external leaks.

The arms will lift empty, but will not with a load on. They hold as the should, but have noticed that they drop a bit fast.

Some DB experts on facebook suggested it may be the dump valve, which made sense to me. Changed that for one I know works, no better.

It was working perfectly until I got to the end of the furrow, always has. Relief valve has pressure. Hydraulic top link from the spools works as it should, in both single and double pump setting.

I have been told what else it may be, but if anyone on here may have a suggestion, I'll let you go first.

My 1210 sometimes gives bother with dirt getting in the 2 valves under the dump valve. You have to undo the bolt above the one next to the dump valve and push a pencil into the valve to pull it out and clean it. The same with the one under the dump valve

 

[Boohoo]

The 3 way valve in the right position isn't it?It hasn't moved by itself or been moved by accident? Have you tried disconnecting the assister ram and lifting the linkage in L?
Have you got pressure at the tipping pipe and the pipe going to the assister ram?
There isn't much to the system really

Eliminate the simple things first before delving too far.

 

[Viconacrobat93]

Hi, sorry to hijack the thread, but I have a 1390, and the lift will work no bother to rise, but when lowering it judders and shakes the whole cab. Anyone know what would be the cause of that?

 

[Selectamatic]

Hi, sorry to hijack the thread, but I have a 1390, and the lift will work no bother to rise, but when lowering it judders and shakes the whole cab. Anyone know what would be the cause of that?

Lowering to fast…? Try slowing it down a bit… does it still do it…?

 

[Viconacrobat93]

Lowering to fast…? Try slowing it down a bit… does it still do it…?

If I go very very slow it doesn't do it as much. But if I put it down at normal speed it it jumps

 

[Boohoo]

If I go very very slow it doesn't do it as much. But if I put it down at normal speed it it jumps

What happens if you slow it down with the lowering control?

 

[Viconacrobat93]

What happens if you slow it down with the lowering control?

Lowering control? Which lever is that? ( I only got the tractor recently and have been searching for a good manual on it)

 

[Netherfield]

Knob numbered 22 here is for the lowering control, somewhere on the right hand side of the cab.

 

[Boohoo]

Lowering control? Which lever is that? ( I only got the tractor recently and have been searching for a good manual on it)

There a 2 different types of linkage controls on the 90 series, depending on what age it is. If you post a picture of what you've got I'll try to get the relevant part of the manual.
If you're on Facebook there are a number of David Brown groups with parts and operators manuals available to download.

 

[Viconacrobat93]

View attachment 1033194

Knob numbered 22 here is for the lowering control, somewhere on the right hand side of the cab.

Ahh yes, I know that knob. Actually it is broke on mine. I checked under the cab and the knuckle (part 25 on the diagram there) is broke. Maybe that's the problem? I can't adjust the oil flow then?

 

[Netherfield]

Ahh yes, I know that knob. Actually it is broke on mine. I checked under the cab and the knuckle (part 25 on the diagram there) is broke. Maybe that's the problem? I can't adjust the oil flow then?

Part 25 is a 1" x 1/8" tension pin, I think you may mean part no 24 which is K203623, Barclay Williams may be able to help although there is one on eBay in Israel.

Try a Google search with K203623 ,mostly seems to be abroad.

 

[Viconacrobat93]

Part 25 is a 1" x 1/8" tension pin, I think you may mean part no 24 which is K203623, Barclay Williams may be able to help although there is one on eBay in Israel.

Try a Google search with K203623 ,mostly seems to be abroad.

I got it fixed today, seems like it was yanked out rough by previous owner but I got it to fit back properly. Used it to adjust the oil flow and it slowed the hydraulics when lowering, but the juddering is still in them when lowering at a normal rate

 

[JRspark]

The 3 way valve in the right position isn't it?It hasn't moved by itself or been moved by accident? Have you tried disconnecting the assister ram and lifting the linkage in L?
Have you got pressure at the tipping pipe and the pipe going to the assister ram?
There isn't much to the system really View attachment 783082
Eliminate the simple things first before delving too far.

is there an index to go along with this diagram? I have been searching for something like this to help me troubleshoot hydraulic issue with 3 point arms not working. it looks simple but more information would be helpful.
Thanks Rod