thwaites steering problem.

[ivor]

Hi,I'm new to this forum and new to working on Hydraulics.I have an elderly Thwaites Dumper model number 12-53222.It has a 3 cylinder motor and twin rams on the bucket.The problem is the steering is ok, then all power goes and I can't steer the thing.It can happen at any time no matter what the ram position is.It doesn't seem to effect the bucket rams.I've changed the oil and filter also had new seals in the steering ram,though the fitter said it was very stiff.( still leaks a bit). Any suggestions gratefully recieved thanks!

[SRB]

Hi Ivor, could be a fault with the hand metering unit (pump on end of steering column), wouldn't have thought it was a ram issue if its ok then goes, i would check up on the reseal because of leak, rod might have a dink in it.

just my £0.02 worth.

SB

[essexpete]

It sounds like a sticking valve or air lock. Has this got the small cylindrical orbitrol unit that didtribute oil to the steering (and also acts as a hand pump)? Or is it a really old model with steering drop arm moving a spool valve to operate the ram?

[ivor]

Hi, thanks.As suggested I'm fairly ignorant of hydraulic matters and the component names so apologies.The steering column has two pipes going to ram and two others to system.
I've had the dumper about 8 yrs and it's always had a problem but it's much worse lately,not really safe to use.I always seem to get into trouble with a load (moderate)on and manoevering at low speed.The main swivel pin has quite a lot of play in it and I did wonder if it was causing the ram to lock but I'm pretty sure it isn't the cause as it doesn't seem to matter how rough the ground is.ie it locks up on the straight and level as well as rough.