Further forensic examination of the power assist on the restored grader above leads me to the following conclusions:

This is an upgrade made post purchase and didn't come from Caterpillar.  It uses the standard steering rod support bracket - but if you look closely you can see that the bracket has had a section cut out of it and it has been welded (I assume) back together to give more clearance for the power assist unit.

 

Here's what the original bracket looks like on my grader:

 

I've had a look around and I see that Eaton still sell this sort of steering power assist units here:

www.danfoss.com/en-us/products/dps/steer...s/torque-generators/

I don't know if 131 Nm / 1,160 lb-in of torque will be enough though.  Eaton seem to think these units are best for small tractors, which I'm not sure the 212 really counts as...

It will be a huge difference in the steering with that unit. We had one on a loader tractor as a kid, it was night and day difference after Dad put it on! That is 96lb/ft of added torque assist.

Hi, LangdonStevenson.
I don't know what that one is but it sure does look a lot like the original Rivinius power steering booster that was fitted to a LOTTTT of earlier Cat graders, 212s. 112s and 12s, maybe even early 14s too. It still pays to use the lean wheels as well for sharper turns but it certainly makes minor corrections when you are working a lot easier.

Just my 0.02.

www.acmoc.org/bb/discussion-d72/28632-qu...9k-steering?start=10 I stand corrected. If you scroll down a couple posts it will tell you all you need to know.

Deas - thank you, that looks spot on. The Internet seems to know nothing about Rivinius other than a patent, but based on the Rivinius specs I'm now sure that the modern Danfos equivalent will do the job.

Kracked1 - thank you for the link to edb's post.  That tells me everything I need to know.  I will have to find and mount an appropriate pump on the power control box, and set up an oil reservoir, but it's all doable with a bit of time and effort. It also opens the way to fitting up an hydraulic ram to tilt the mould board which would be nice...

any assistance is better than none. the other thing that helps with steering on anything correct tire pressures and lube, a properly lubed mechanism will do wonders to how it feels.

Trainzkid - agreed. It's interesting reading that the Rivinius units wouldn't turn the wheels when the grader was stationary (and they provided 1200 lb-in of torque) but gave more than enough steering effort when the machine was moving. Checking tire pressure and making sure the steering pivots are lubricated and moving freely seems like sound advice too. I will definitely do that. I saw someone lubing a Cat 12 the other day on Youtube and there were over 60 points! I guess that' just another reason why hydraulics are better...

Speaking of edb, has anyone heard from him lately or know how he is doing?

Hi, D4Jim.
No. I have not heard either from edb or about him for a while. Maybe some of the Chapter 19 people have seen him or heard from him as he hails from that part of the world.

Just my 0.02.

the hydraulic machines have just as many grease and oil points. many modern graders get plumbed for a manifold system to speed up greasing. one problem the grease lines get busted or blocked and you dont know if its greasing properly or not. nothing beats being eyes on with every grease point then you know its properly lubed. side benefit you can spot problems like worn pins etc before they become big problems