Power steering pump pressures

Hi, query for rocKWiz or anyone can jump in.
Bought a 2000 era power steering box for the Bantam rebuild, had a bit of ginning around making up a really heft adapter plate and can cobble together using existing Mazda T3500-T4000 mounting bolts.
Wondering what sort of psi should be running ( 4&3/4 turns lock to lock), going to use the original Land Rover (1990) porwer steering pump, resevoir and lines, but have to put different ends on the rigid part of the lines as have to route them in a different direction because of tilting the cabin. L/Rover 200 TDI good book says theirs run at 900-1000 psi, so how does that equate with original Mazda pressures? Thanx in advance
Dave_64

Geof,
P/M sent, Dave

Had to end up downloading a workshop manual in PDF form to locate the power steering pump pressures of the circa 2000 Mazda T4000.
They call it an"Engine speed sensing steering" whatever that means. Give operating pressures at 1490 psi.
Now, this set up cobbled together with the Land Rover 200TDI power steering pump (which puts out only 900 psi) looks a bit mismatched!
I have started the engine after fitting the pump and the steering box, all new lines etc, just checking for any leaks. Bled it the way suggested (had been didconnected at the Pitman arm) with the engine OFF, did this until looked like all air expunged from system.
Started the engine and with the half shaft sticking out of the top of the steering box, wound it back and forth another half dozen times, only had to top up the reservoir a tad.
Hooked the Pitman arm back up to the drag link and with the engine idling over (650RPM) could wind the steering box around with the half shaft, could hear the power steering pump load up enough to just drop thr RPM a bit, and with both front wheels on the deck, could still turn them, although not easily.
I'm thinking that the discrepancy in what the pumps putting out and what the box actually requires is going to make her a bit hard in the mouth.
Manual steering was very heavy, at stop just about had to put a foot up on the dash to reef her around! Real Armstrong!
Only 4 & 3/4 turns lock to lock (dont know what original manual steering was), wondering other than making it a bit heavy in the steering if it can do any damage??
Dave_64

I don't think a slightly lower psi will make a huge difference, only when parked at guess will you notice the difference and then not a lot by the sounds of it

Paul

Yeah, thinking along the same lines, Mrs.
Had something similar fitting a Holden power steering into a Jeep but run ing a Ford pump. A bit heavy in the mouth at low speed/low revs but quite nice to drive at highway speeds.
Dave

I put a Ford XF power steering pump on a Landcruiser 60 series I think it was steering box in HJ 45 with a 6.2 Chev V8 diesel coupled to a 5 speed cruiser box and a Hayman Reece 6 wheel conversion

It just sort of worked :silly: :silly: :woohoo: :woohoo:

My point is sometimes when we just do it, it actually goes pretty good

Im sure it will be fine, if the pressure does turn out to be a bit low maybe change the pulley size or something similar might help at idle, dunno

Paul

Better to have it on the low side rather than overdoing it and ending up over-stressing the steering components.

Yes, you don't want to break/fracture a steering component. Or stress it enough to have it break at speed.

I have Isuzu PAS on the bus. Very very aware not to haul on the steering unless moving.

Thanx for the comments, Guys. Trouble is as we all get a bit older, we get a bit spoiled! Days of hauling old F model Macks and manual Petes are well and truly over! Cheers

Here is an incomplete post, as he is not done yet, of putting power steering on a Brockway. Tom is an engineer by education and can possibly answer some of your questions. If you need his email address please PM me here or on BMT.
www.bigmacktrucks.com/topic/67511-1968-b...er-steering-upgrade/