Ford 5610 lost hydraulic function

[Renardiere]

Hi, I'm hoping for some advice or maybe confirmation of my logic in diagnosing this hydraulic issue. I have an Old Ford 5610 (mid 80's) which suddenly lost all hydraulic function following the use of a tipping trailer. I assumed dirty oil from the trailer cylinder had been the final straw for filters which were slightly overdue for a change. I have changed all the filters and cleaned the low pressure screen on the transmission pump. This tractor also has the auxiliary engine hydraulic pump which also has had a new filter. The case was fully drained and new oil to fill to correct level. Having done all this I still have the same issue. Won't lift the three point linkage. I have removed the loader for the moment to allow servicing of the tractor so can't test the external services.
One thing I have noticed that for a brief period when starting the engine the three point linkage arms will start to lift. In fact I can lift them all the way up by repeatedly starting and stopping the engine. My guess on this is that for a brief period there is useful pressure which as it builds is then dumped ? faulty pressure relief valve. Is changing this PRV the next step? Is this the valve immediately forward of the filter on the transmission pump? or is there another one somewhere?
Hope someone can help.

Many thanks

Alan

 

[ROUSTABOUT]

Is the tractor an R or a Series II ? And it has the aux pump that is driven by rear of camshaft ? First guess is your relief. It either blew or more likely got trash iñ it. Probably happened on let down of trailer. I love them tractors. Only complaint is the reverse. Low reverse too slow, high reverse too fast.

 

[Tx Jim]

Years ago I owned a Ford 5610 with closed center load sensing hyd's that breakaway coupler malfunctioned stopping hyd cylinder from operating correctly. There was also a load sensing valve on the top of rockshaft housing that failed. My 5610 caught on fire & turned into a very crispy critter! For my use older Ford tractors with open center hyd's similar to my Ford 6700 suits my needs better than the CCLS hyd system. I may still have a 5610 tech manual.

 

[Renardiere]

Hi, thanks for the replies. I have no idea whether this is an R or Series II. I should have added that I'm in the UK and this is a UK built machine. Yes auxiliary (gear) pump is driven of the camshaft at rear left of engine. Damaged PRV makes most sense to me. Can you confirm that this is the item immediately in front of the transmission hydraulic pump filter? I hope that this is all I have to replace. Getting the top cover off would be a nightmare as there is a very rusty cab sitting on top.

Regarding reverse speeds I find that this is an issue with most shuttle type gearboxes. My Antonio Carrera is just the same.