Adjusting power steering pump

[rujib]

Hi,

My power steering on 7745 seems lazy to say the least. For example when the tractor is standing (not moving) in a clean concrete slab, it is difficult to move the front wheels to either side.
When turning the steering wheel, I seem to hear a screeching sound coming from the steering pump. I guess it is oil relieving through the relief valve in the pump.
Is it possible to adjust the relief pressure in the relief valve, by adding a spacer to close the spring more or by adding a stronger spring?
Secondly, assuming I could do either of the above two options, could there be any downside side effect

Thanks for any advice on this matter.

R

 

[hve]

Well...... i did a bad thing,
i put a 3mm packer under the spring on the Steering ram relief valve on my 6745, and 2 things happened.....
1. steering was no longer lazy , (but i forgot i had adjusted it yesterday until ......)
2. When i reached full lock.... Bang ..... smashed the front housing off the alloy hydraulic pump
i guess there is no pressure relief valve built into the pump on my model (Calzoni ram, not sure about the pump, have not gotten it off yet.... job for tomorrow)

 

[hve]

Well today i went to the local tractor wrecker to pick up my new FEL and a few bits including a Power Steering pump....... interestingly completely different to my old one.
All the Zetors at the wreckers had cast iron 3 port pumps (that must have a relief valve built in) bolted directly to the front of the block (aka compressor crankcase)
my old pump (while factory original) was all aluminium and bolted up via a cast alloy adapter plate, and has a much smaller shaft and coupling and no built in relief valve............... Italian crap?......... cannot find a brand name on it under all the gunk.
but only 4 bolts held the top plate on, so no wonder it broke when the relief valve was er... over adjusted (oops)
i expect the Cast iron pump to work much better at much higher pressure
but if i do brake another pump i am just going to fit a belt drive pump off a car (as i have 6 in the shed) and the worst that can happen is the belt slips

 

[Renze]

Original pumps were all cast iron, our 5245 also had a cast iron, which was a 1986, way later built than your 6745

 

[dave_peters]

We bought 2 6945's new, one had Calzoni steering and Lucas starter, whilst the other had Zetor steering and PAL starter as origional equipment. we had no trouble with either steering, but the Lucas starter turned out to be Magnetti Morelli made and didn't last a year. I think you have a calzoni pump, but you will probably be better off with a Zetor one.

 

[Renze]

Dave, now you say it, there have been some years that they also used Calzoni servo cylinders for the powersteering... Although i have never seen one for myself with it...

 

[hve]

Yes, as per my earlier post i have a Calzoni Ram, so stands to reason the pump will be of Italian origin too.
Renze.... i can send you a photo by email if you like.