NH 7635 Dual Command Issue (also slow loader)

[Half Pipe]

It's a kinda DIY quick fix, be ok for occasional use, but important spool fully open.
But if properly plumbed in and it's not that difficult, then rear linkage and spools will work normally when loader joystick is in central position

 

[monkspill]

It's a kinda DIY quick fix, be ok for occasional use, but important spool fully open.
But if properly plumbed in and it's not that difficult, then rear linkage and spools will work normally when loader joystick is in central position

That’s interesting, how should it Be plumbed properly then?

 

[Half Pipe]

I'll try get some pictures, might take a day or to tho

 

[monkspill]

I'll try get some pictures, might take a day or to tho

Appreciate it, confused now though, the book suggests it’s closed centre...

Also suggests the flow should increase when turning to the right but on my machine the flow increases when turning the control to the left...


The spec says 14.5GPM, should that lift a loader fairly quickly?

 

[monkspill]

Any more joy on this folks?

 

[Half Pipe]

Sorry for not getting back to you sooner, been one of those disappearing weeks!
Our tractor hasn't had the loader on it for years, but loader brackets etc still on it.
Just nipped out and studied it a bit, it looks more complicated than the valve block we fitted to a tl100.
This one on same model tractor as yours with the 2 rear flow adjustable spool block has 3 pipes connected to loader spool, suggesting it's load senseing, but tractor only has constant rate pump.

 

[Half Pipe]

this picture is taken from rear looking in at tractor spool block, light shining on the screw for adjusting detent

 

[Half Pipe]

this picture is taken from right hand step,
It shows the smallest pipe connected to loader spool block, presume this is some sort of load sensing, must divert oil to loader valve. The small metal pipe similar to a brake pipe connects to bottom of tractor spool valve

 

[Half Pipe]

this picture shows return pipe from loader valve T'd into rear valve return pipe
And the feed pipe is just T'd into the feed pipe for rear valve

 

[farmerphilly]

I’ve got a 6635. Plumbed direct into hydraulic system. We have had issues with the joystick and cables not being held into joystick correctly. The loader was going slow one day simply because one of the spool levers was engaged! It’s being a brilliant tractor

 

[monkspill]

Thanks for that much appreciated. As you can see my loader goes in to float when you pull the lever back which is strange, I’m wondering if someone has switched the spools around the wrong way for the loader and then change the joystick back to front to get it to work as a result? See videos and tell me if you think the loader is slow, maybe I’m just not used to having to give her as much Rev as other machines...

 

[Half Pipe]

This might help
https://thefarmingforum.co.uk/index.php?threads/trima-loader-hydraulics-plumbed-into-nh-tla.76820/

Or maybe best asking a dealer or manufacturer for some fitting instructions

 

[monkspill]

God knows, for a start there seems to be air/vacuum in the loader rams as there’s a judder when lifting and also if you hold the quick detach spools and press them against the valve block (detached) you can hear the air running out. Secondly, one of the loader pipes is joined with a very small pipe, I will try and get some pictures.

 

[Muck Spreader]

Have you checked the hydraulic system especially around filters, LP pipework for leaks that could be letting air into the system. You will see the oil on the dipstick become frothy after a few minutes.
We have an L95 with a loader fitted (not from the spools) and it's always worked at a very acceptable speed.

 

[monkspill]

Thanks for the response, do you know how many seconds roughly to fully lift the loader?

This pipework here seems as if it could be restricted, I’m wondering why it’s been joined. Also had her serviced last week and it’s the same. (This photo taken prior to filters).

Another issue does anyone find these slow starters or that it could almost do with a bigger battery?

 

[Half Pipe]

Thanks for the response, do you know how many seconds roughly to fully lift the loader?

This pipework here seems as if it could be restricted, I’m wondering why it’s been joined. Also had her serviced last week and it’s the same. (This photo taken prior to filters).

Another issue does anyone find these slow starters or that it could almost do with a bigger battery?

The joined pipes in photo look to be going up into cab, most likely heating or does it have air con?
Usually good starters, but could be weak battery or slow starter motor

 

[monkspill]

Hello again, sorry for the slow reply... yes it does have air con. Still can’t get my head around this, when the loader spool is engaged you can hear the tractor struggling & the pump moaning slightly. Pump was actually replaced a few years ago I believe (May be wrong). It makes the steering heavy unless giving it plenty of Rev. The spools are then quite hard to take out of the detent position and come out with a bit of a bang. It’s almost as if there’s no flow in the system and you’re dead heading the hydraulic pump. When you take the backend return off you can see no oil flowing back in when the loader isn’t being used but is engaged. It’s almost as if there should be some sort of relief valve or something to let the oil circulate until the joystick is used. When you raise or lower the joystick it takes the load off the system and the tractor returns to a normal Tickover engine sound compared the the straining when the spool is engaged.

 

[monkspill]

To clarify the issue with the dual command was indeed the wires so thank you to those that suggested that!

 

[monkspill]

Should there not be a free flow return when the loader joystick isn’t being used to save the pump from “dead heading”?

 

[Half Pipe]

If you have loader spool block being fed from a rear spool then it should have a flow in the return pipe, if not it means oil flow must be going through rear spool relief valve and it that is what's happening then oil will be alot warmer than should be and most likely the reason your rear spool detents are sticky.
Will also be reason it's had a new oil pump