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-   -   Just installed a Lares 974 power steering box - lack of assist at idle (https://forums.maxperformanceinc.com/forums/showthread.php?t=837111)

njsteve 01-12-2020 05:08 PM

Just installed a Lares 974 power steering box - lack of assist at idle
 
1 Attachment(s)
I just installed a Lares 974 steering box in my 75 Firebird 455. (2-1/2 turns lock to lock). Pretty uneventful R&R. After bleeding the system (no bubbles), and taking it for a test drive I noticed that there is much harder steering effort required at idle. When backing into the garage it feels like close to no power assist. It is using the original Saginaw pump.

Is this a low pressure issue? Is there some modification needed to get the assist up at low RPMs?

FYI: This is the car http://forums.maxperformanceinc.com/...ghlight=gramma

JLMounce 01-12-2020 07:51 PM

Yes more than likely that’s the case. Here’s a link to pump mods. You probably need 200-300 additional psi.

http://pozziracing.com/camaro_steeri..._Pressure_flow

The Champ 01-13-2020 06:57 AM

When I put in the Lares 972 (basically the same box), I installed a new Lares power steering pump (the old pump had issues) at the same time and everything worked fine.

tempest1964 01-13-2020 01:58 PM

Nice link Jason

njsteve 01-13-2020 08:44 PM

1 Attachment(s)
I spoke with the Lares Tech line today. They said it is common on old pumps that if you bleed the system at running idle speed, it will hold an air bubble at the valve in the back of the pump and never clear it, which will result in the exact situation I have - loss of assist at idle. That's why they recommend that you bleed it with the coil wire out and just at cranking speed.

Attached is their remedy - basically remove the pressure line from the back of the pump, then remove the fitting itself. Access the valve behind that fitting. t will probably be sticking in the bore somewhere in its full travel. Push it up and back until it moves smoothly. Then reassemble and re-bleed at cranking speed only. He said that the stock original pumps put out more than enough pressure to operate this steering box at idle.

I will try this in the next couple days. Hopefully it works. He said there was no need to buy a new pump (which was nice since I fully expected him to say you should buy a brand new pump from us...)

I will say the 974 box is really nice. Lots of firmness on the road - like a modern car and not like the old, anesthetized, one-finger turning of the original box.

Geoff 01-14-2020 04:30 AM

I hope this works for you........
But the question begs: the valve wasn't sticking before, why would it be sticking now, & why just at idle. I have removed/fitted lots of those pressure valves & they have always been quite a loose fit, would take a large chunk of debris to jam it.

njsteve 01-24-2020 07:30 PM

Lares said the stock original pump's output pressure would be fine. They recommended to pull the pressure hose fitting off the pump and make sure the valve inside moves freely and then reinstall the fitting and hose. I was going to do this a week after installing it but it seems that whatever tiny air bubble(s) that were still inside the valve managed to disappear after a week of sitting. So the system does work nicely now. Box is very firm. It has a real road feel to it now. I did have to reset the tie rods as the steering wheel was about 1/4 turn off with the new box. Wheels are now straight and steering wheel is in the right spot and all is good in the world

389 01-27-2020 06:43 PM

Pick up a Pressure kit from Bergeson and remove all the shims on the pressure valve...


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