Ford 7810 power steering problem

[ICP]

Hi there, Having an issue with the powersteering of the 7810 (1991 4x4). The original orbital unit had a crack on the housing and was badly leaking oil.
I replaced with a new unit (see pic) . The steering works intermittently now and feels like its working against itself if that makes scene it will steer but it is difficult at times, Fluid level doesn't drop Filter has been changed.

Is there a way to bleed the system?
There were no instructions on the new unit with which pipe goes where and I just changed pipes around until steering started to work, could I have busted something in the unit doing this ?

Any help / Ideas greatly appreciated,
Thanks.

 

[forblue]

Is that motor exactly the same number as original one as fords at some time fitted a pressure relief valve in the motor and not in the pump...there is no need to bleed system just lock to lock and top up pump reservoir..

 

[ICP]

thanks for reply,

Im not sure if the motor is exactly as original, it isnt the same shape the original one which was a complete cylinder. The replacement had a rectangular area where pipes connect to unit.

I will try Lock to lock to see if it improves anything.

 

[Mr Happy]

thanks for reply,

Im not sure if the motor is exactly as original, it isnt the same shape the original one which was a complete cylinder. The replacement had a rectangular area where pipes connect to unit.

I will try Lock to lock to see if it improves anything.

Port configuration for a conventional steering unit.

 

[Mur Huwcun]

Well T and P are clearly stamped on the orbital therefore double check twice that these are the correct way around. The other two won’t matter as if they’re wrong way around tractor will go left when it should go right so it will be obvious!!! As said you need to identify where the PRV is as there’s a cause the first one cracked. Orbitals usually have one but some Ford pumps had them aswell. Steering orbitals are not something to play about with as they can easily turn into a hydraulic motor and spin the steering wheel and at best break your thumbs and even much worse.

 

[ICP]

Thanks for the info lads,

makes more sense now, What does T and P stand for ? one for power form the pump and the other return to the reservoir?

I will check to see if I have them in correctly .

 

[Mr Happy]

P = pressure port, so that's the inlet port to accept the flow from the pump. T = tank, so that's the port that returns the flow back to the hyd reservoir.

 

[forblue]

When changing a hyd pump or motor it's important to fit the hoses in correct order as seals can be blown if not....

 

[ICP]

Thanks for reply's, checked the lines and they are plugged in correctly. I had tried different combinations when I installed the unit first, so I hve probably ruined the seals inside the unit .

Expensive Lesson Learned!

I will probably send unit to be checked out/ resealed.

Is there any way of checking the flow of the pump? or do they ever give bother? I doubt its the pump as steering was working grand prior to orbital unit replacement just pis*ing out oil.

heres the pump,,, ,, ,

 

[forblue]

Like all pumps than can wear but very reliable most common are oil leaks, flow and pressure check can be made just connect to pressure port and return port with pressure gauge and gate valve between, turn valve off until correct pressure is reading along with flow gauge if you have one, do not dead head pump unless you know it has it's own prv as you say if it was ok before new motor fitted then it should be ok...

 

[manhill]

Thrust bearings on the stub axles ok?

 

[Toms820]

Sorry to dig up this thread but when you removed the unit did you do it without splitting the tractor? Also can they be re sealed or is it a brand new steering unit?

 

[Mr Happy]

I can't answer the question about splitting the tractor but the steering units can be resealed. However I would send it to a company that know what they are doing. I would recommend B & N Hyds near Coventry.

 

[Barleymow]

Sorry to dig up this thread but when you removed the unit did you do it without splitting the tractor? Also can they be re sealed or is it a brand new steering unit?

No need to split tractor, just move header tank for radiator not a hard job