Ford 7740 SLE hydraulic problems.

[Mattgus]

Hi. I’m new to this form, so this will be my first post here.
i got an Ford 7740sle -96 that seems to have some flow problems in the hydraulic system.
the tractor is equipped with front loader.
the problem is that when I put the tractor in gear and hold the clutch partly depressed I have very low flow in the hydraulic system, front loader, rear lift and auxiliary hydraulics.
I have measured the flow and pressure according to work shop manual, and it is within specs. the problem is only when I have it in any gear and party depressed clutch.
Any idea? It is pretty frustrating to use any equipment with this behaviour....
The machine is located in Sweden.

Hope to find someone that can point me in the right direction....
//Mattias

 

[Dave W]

Think that's just how they are. My TS does the same

 

[Mattgus]

Hmm. That’s kind of strange.

 

[ridger]

Hmm. That’s kind of strange.

Not really strange, surely if clutch is half pressed it will be using the oil that should be going to loader.

 

[forblue]

Has it got two pumps or ccls..

 

[Mattgus]

I can’t really see how the clutch could use up the oil unless there is an leakage in that circuit.
it is a ccls system.

 

[ridger]

Because if you are slipping it then the oil isn't dead ending in the clutch pack and coming back out into the guts of the tractor I'd assume in layman's terms

 

[ridger]

Maybe put her in a lower gear and dont slip the clutch?

 

[fieldfarmer]

I can’t really see how the clutch could use up the oil unless there is an leakage in that circuit.
it is a ccls system.

Yeah all that I have driven do it , 20 yrs ago was well peeded off with one on a post banger having to neutral the gear box just before the post so the operator of the mast could use the spool block on the banger. ts115, sle.

 

[forblue]

Can i correct a few misconceptions, the 7840 could be had with a hyd operated normal dry clutch with 12x12 no splitter gearbox, or 12x12 with so called dual power, or 16x16 electroshift and could be had with two hydraulic pumps, one was transmission driven same place as old 10 series the other pump was fitted to engine in same place as older series. or it could be had with the ccls pump, i have never driven or worked on one with a loader but i do know that the 16x16 transmission use's more oil when feathering the pedal [which controls pressure in a clutch pack] so it's possible that this fault can show up more so when tractor is no longer new, i worked on a 7740 ccls pump which from new would show low pressure light on when backing up and using hyd lift to hitch a trailer and when feathering pedal, Fords asked me to fit an extra pump [engine] as well with extra oil pick-up and another filter, the feed i put into supply pipe to transmission still the same! should have had another box as i was sure an internal loss caused this but as far as i know this tractor is still around near me............

 

[Joe McLaughlin]

I know this is an oldish post.

The engine mounted pump is only the power steering pump. No sle 40series had that and all had one pump mounted inside the right wheel which houses the Power steering pump, charge pressure pump and the variable piston pump..... That's alot of work for a tractor without adding a loader in the mix!

 

[forblue]

I can assure you the sl 40 ser had two pumps the engine one was Not a power steering one it used oil as an extra when using the spool valves via combination valve i know that as i was asked by Fords to fit this pump to a customers sle which had the ccls pump so i made up suction and pressure pipes, the reason was red warning light of low pressure on when feathering the clutch pedal and using the hyd hitch at same time it helped but never cured it, the tractor was new when owner noticed it so all work was done under warranty...as regards a lot of work for the ccls pump rubbish, 10ser tractors had loaders with just one main pump to do work.

 

[Joe McLaughlin]

Would that have been a modification to cure an issue and not a standard option from the factory? Never seen an auxiliary pump on an sle yet.


I'm looking to fit a loader to our 1993 7740 sle maybe you could help? It's an old 2002 Trima 465 and I'm unsure where to connect the 3 hydraulic lines.

Any of your wisdom would be greatly appreciated fordblue.

 

[forblue]

The spool valves must be used to supply oil return same way or return to top cover if you have two metal caps on press and return pipes before they reach spools use these if spools are used and flow needs to be turned down do it only on spools and not on a separate valve for loader if it has one one, as on sl it will burn out out front pump, specifications for tractors are made to customer requirements and i agree the sle was normally sold withe all the gadgets when first released but after quad mod sle's could be had with things like ccls pump and manual hyd lift, edc with or without wheelslip, same as we had a couple with two batteries mostly single, places like canada and nrth america had two because of cold, didn't help over here when starters were getting old, getting back to your sle i would not advise fitting an additional pump a decent ccls pump will be sufficient.

 

[Joe McLaughlin]

This is a used loader so no instructions ect... All I know is it has two 1"pipes (roughly) and a 1/4" pipe which I assume to be a signal line. It came of a 7740 and wasn't plumbed using the spool valves.... Whith only having two spools I don't want to use up one anyway.

 

[Boohoo]

This is a used loader so no instructions ect... All I know is it has two 1"pipes (roughly) and a 1/4" pipe which I assume to be a signal line. It came of a 7740 and wasn't plumbed using the spool valves.... Whith only having two spools I don't want to use up one anyway.

A while since I had anything to do with a 40 and more experience of piping later tractors for load sensing but aren't there fittings on the pipes for the rear spools that the 3rd and 4th spools would be connected to? Or am I thinking of later models? If the connections are there use these for your flow and return. The sensing line needs to be connected into the tractors sensing line with a shuttle valve, a tee won't do. There'll be a 90 bend somewhere in the line between the rear spools and the pump that can be removed and replaced with a shuttle valve.

 

[forblue]

If you have only one pair of spools the metal pressure and return pipes that supply the spools will have metal plugs [female] on them these are used if fitting extra pair of spools, pipe to loader valve then look on the small metal pipe to existing spools may or not have a blanked tee fitting tha\t's the sensing line so fit your one from loader valve and it should work.........

 

[Mattgus]

@Joe7740.
1st pic is showing my pressure hose to the loader valve.
2nd pic showing the return hose from loader valve(it’s quite hard to see but it is in the middle of pic to the left)
3rd pic is showing the LS hose to loader (on the right side of the aluminium block In center of pic)

hope this can help u.

 

[bobk]

Buy a loadall , you'll never go back .

 

[Mattgus]

Buy a loadall , you'll never go back .

i got an wheel loader as well.