Steering jam

10.6

Seems like the EVO is within range.



What happens if connect 12V to the terminal?

onkelmicke said:

What happens if connect 12V to the terminal?

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I wouldn't assume 12v direct is safe and may cause damage. I don't see doing that as a process in the manual.

Key on, then check for volts are the connector on the harness, first. Do you see more or less than 5v?

I'd ask again about codes, but you can't check when it's all apart.

I couldn't fit the probes into the socket so I will rig that some way, but I'm done outside with the cold and darkness for today.

It would be interesting to understand how the EVO actually works. I would guess there is a moving piston inside the snout of the EVO, acting upon the valve piece?
The valve piece in itself letting nothing thru the holes and the mesh, but instead around its circumference?

onkelmicke said:

I would guess there is a moving piston inside the snout of the EVO, acting upon the valve piece?

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As I said above, yes, the 'valve' is actually a piston that shunts to a different position, altering fluid flow thru the housing that holds it, based on inputs

That piston moves when the coil is energized - flow thru the EVO is controlled by the position of the piston inside. The piston and the housing combined amount to a valve.

On cars without EVO, the pressure relief valve lives on the same port on the side of the pump. On our cars, the EVO serves to do the same job. I can understand whine...it's all too common, sometimes cured by a flush, fill and treatment w/lucas power steering treatment. What I don't get is why steering would lock up. I can see blowing a hose if the pressure relief is blocked, tho.

The photo of the piston and screen looks clean - is that after you cleaned it up? A blocked screen might cause runaway pressure. If I can dig out my spare pump/EVO I'll take another look.

More discussion here: http://s7d9.scene7.com/is/content/GenuinePartsCompany/1232274pdf?$PDF$

KMT said:

What I don't get is why steering would lock up. I can see blowing a hose if the pressure relief is blocked, tho.

The photo of the piston and screen looks clean - is that after you cleaned it up? A blocked screen might cause runaway pressure. If I can dig out my spare pump/EVO I'll take another look.

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Agreed. Locking up is weird. Not only weird but downright dangerous. Another thing is that it locks up with the tires to the ground, but not in the air, i.e. only with the added resistance in play.

It made no difference to disconnect the EVO terminal, so any blocking action has to be mechanical.

The piston/valve wasn't cleaned up and the mesh screen looks permeable enough. If there is a pressure relief valve inside of it, it may or may not be blocked/stuck, I could not blow hard enough manually either way to make it open.

Also, in the link above it was mentioned that the EVO should rattle and it does that a bit so it seems fine.

The separate piston and spring are stuck inside my spare pump so I can't compare to yours, but that screen must cover a passage. My EVO ohms out at 16.5

If it was about that piston sticking, it wouldn't have come out when you removed the EVO.

Did you get the new pump yet? I'd wonder if it comes with a new piston & spring.

KMT said:

I can see blowing a hose if the pressure relief is blocked, tho.

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It blew something, but I don't know what. It wasn't a hose. A fountain of steering fluid made a hole in the hood lining and quenched the whole engine compartment. The drive belt was frayed at the rear side edge.

Now the return line hose below the oil filter has been opened, and with the EVO out, the steering is still frozen.

How about that? That leaves any valves in the rack or any hose on the pressure side........

I thought you said before that it steered ok with the engine off? Do you have the front wheels in the air?

KMT said:

Did you get the new pump yet? I'd wonder if it comes with a new piston & spring.

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Good thinking! Yes it has arrived but I hadn't even checked it out yet. I went out to do that just now, and yes, there are those parts in there! I would not have thougt so... Anyway, I don't see any difference to the old one, the oil tastes the same, and it doesn't react to trying to blow thru it. I am convinced that there was no fault to the pump (it may be now) or the EVO.

However I still need to get the old pump out to check, and possibly switch to the new one. Still haven't managed to get the tube out... there must be another fastener that I can't see or reach. I put the camera down there a far as I could next to the distributor and my guess is that it can be seen in this photo, and it looks like it needs to be removed from below. Can't imagine how.

KMT said:

I thought you said before that it steered ok with the engine off? Do you have the front wheels in the air?

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My first conclusion was that with the engine off the steering is frozen stuck. With wheels off the ground it works and is light moving. With engine on and pump running the steering works but is stiff and the pump screaming. Wheels up is working normal. Unfortunately that has not changed in the course of working with the parts. Have the wheels to the ground now.

I got the piston and spring out of my spare pump. It looks like there is another very small spring inside and that the pressure relief is internal. I can't blow thru the screen either so my guess is that the internal port is normally closed and only opens when pressure goes too high. The screen and internal valve are pressed into the piston, apparently and not meant to come apart/be serviced, other than inspected and cleaned if needed.

I agree the rack is looking like the issue now and/or the high pressure line.

onkelmicke said:

Still haven't managed to get the tube out... there must be another fastener that I can't see or reach.

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This is what the lower tube looks like out of the car (image courtesy TBSCshop):



You should be able to see the entire tube clearly if you remove the accessory bracket completely, as long as the pin with the nut is removed that clamps the ear on the tube to that bracket. Note the only fasteners are two nuts on each end and the pin w/the nut for the ear at the accy. bracket. If those 5 are free, then the tube is stuck on the flanges on the ends.

Apparently there are two types. One like that and another with an extra bracket that is screwed from below. I searched a lot of old threads and mine must be like that. I will look for it tomorrow.

About the rack, are there any chances that any valves in there are replaceable in a practical manner?

onkelmicke said:

Apparently there are two types. One like that and another with an extra bracket that is screwed from below.

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Looking closer at your photos, I think I see a horizontal flange with a vertical bolt coming in from below...


What year is your SC, again?

...any valves in there are replaceable in a practical manner

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The shop manual says the guts inside the housing where the steering shaft connects is one big valve. Not sure how practical a solution that would mean.

About heavy steering efforts:
Low Fluid
...fill as needed

Valve seal cut or twisted
...Replace seal

Damaged/worn Teflon piston seal
...Replace seal

Loose/missing rubber backup piston o-ring
...Replace/install o-ring

Loose rack piston
...Replace rack assembly

Gear assembly oil passages restricted
...Clear/service as required

Bent/damaged rack assembly
...Replace rack assembly

Pump external leakage
... Service per diagnosis

Improper drive belt tension
...Readjust belt tension

Hose or cooler external leakage
...Replace as necessary

Improper engine idle speed
...Readjust idle

Pulley loose or warped
...Replace pulley

Pump flow pressure not to specification
...Refer to pressure diagnosis

Hose/cooler line restrictions
...Clear or replace as required

It's 1990

OK. Can't imagine much of the above being the cause really, exept possibly "Gear assembly oil passages restricted" (wherever that is) ...Clear/service as required
And "Hose/cooler line restrictions" ...Clear or replace as required
Looks like I should check lines/hoses to begin with, or how to remove them.

Thanks

Digging further, I found another section on heavy steering efforts defined as "poor assist or loss of assist" - I don't think this would mean a complete lock up, tho

System contamination
...Inspect system for foreign objects, kinked hose; flush system

Plugged valve screen
...Prior to rebuilding a CII pump*, examine the valve screen for contamination; replace all valves which have plugged or contaminated valve screens
(I think this means the relief valve and it's screen)

EVO actuator sticking
...Replace actuator

I don't see anything about outright lock up in any example. It's not locked up unless the pump is running, so pressure/flow seems to be the issue. If it was a mechanical failure of the rack, it would't matter if there was pressure/flow or not.

When the shop manual discusses pressure testing, and if high pressures are recorded, it says to either check hoses for restrictions, or the flow valve in the pump...clean or replace. The new pump takes used parts out of the picture, leaving the hoses.

The return hose is trivial and costs whatever a store wants for 65 ~ 70 cm of the correct type hose. The factory clamps may need to be sacrificed and replaced with standard screw clamps. The high pressure hose is both rubber and and metal, costing around $50 USD, and a pain to replace/get in out. It also requires new teflon square seals on both ends, but they should come pre-installed. If you find that either hose has come apart inside, that means the entire system needs to be flushed, especially when installing a new pump.

*means Ford type, belt-driven, slipper-type pump with fiberglass-reinforced nylon reservoir, typically found on older models

KMT said:

It's not locked up unless the pump is running, so pressure/flow seems to be the issue. If it was a mechanical failure of the rack, it would't matter if there was pressure/flow or not.

The return hose is trivial and costs whatever a store wants for 65 ~ 70 cm of the correct type hose.

Click to expand...

Well it is seized with engine/pump off. Resistance when turning is what makes it seize (i.e. with wheels to the ground).


On mine the last part of the return line is a simple hose (connecting to the pump) but the parts connecting to the cooler and to the rack are hoses with permanent connections pressed on the line, as in the photos. Haven't found those as spare parts yet.

Pump is out. IC tube is not. With the pump removed I think I can see the extra bracket connected to the engine block.

I was going to lunch one-day in my Hyundai (not trying to rhyme swear) and my steering rack tie rod broke. It busted inside the steering rack itself. Just thinking about another scenario. Cause if your fluid is full pump isn't screaming and belts/pulleys/tensioners are fine.
What about that steering assembly/linkage going into the engine bay? Maybe that's a cause

Inner and outer tie rods are new. Rack 'looks' fine. I don't know about the steering column/coupling, could the coupling go bad?
I'm currently suspecting PS line hoses could be frayed inside. Need to get them out.