ST185 power steering not keeping up

R

Roundy

New member
Hi Guys,

Had a bit of an issue in the motorkhana, which i have had before.

Basically get to a slalom, and it seems i get no power assistance through there and the steering becomes amazingly heavy.

It would seem that this sort of problem is not uncommon through a lot of cars, however i have seen nothing to really suggest how to fix it!

Any suggestions would be much appreciated

Cheers
Nathan
 
R

Roundy

New member
No.

Also worth noting it has an aftermarket PS cooler, but had the same issue with it totally stock
 
A

ALLensTRAC

New member
This sounds like high pressure related vein bypass in the pump. I would rebuild the pump and have a good look inside for anything obvious. If it's only occurring at the limits during a slalom you may have reached it's pressure limit. A quick left to right to left can provide delay in assist. This is why I'm working on electric steering for my car.
 
M

Mafix

New member
and it's not bump steer?
have you done a suspension check over? i'd imagine it's something else.
 
M

MWP

New member
Roundy":25o3vmdh said:
I have only had it occur in the slalom, never noticed it anywhere else.
Click to expand...

After mine first happened at the motorkhana, it also started happening at shopping centres, etc :(
 
M

Mafix

New member
making sure its not a binding issue. I've seen bump steer do some strange shit.

edit: we may be defining bump steer differently. at any rate, before the pump/rack are replaced, the front suspension needs to be checked first.
what fluid are you using in the system?
 
A

ALLensTRAC

New member
Can we have a breakdown of current mods suspension wise? Also when was the last time you opened the PS system? Have you replaced the steering rack? Pump? I know you said you have a cooler but what are the dimensions? Is the fluid thicker or thinner than say Dexron trans fluid?
 
M

Mafix

New member
Roundy":2s8grgz7 said:
Penrite fluid is what i am using

Pretty confident that the suspension is all right.
Click to expand...
isn't penrite a brand name for lots of fluids?
and pretty confident should ever be good enough. it's not that hard to check her over.
 
R

Roundy

New member
Suspension mods:
BC Racing coil overs adjusted for ~2.5° camber, and rotated strut tops for 1° extra camber
Poly bushes all round
Have not pulled out/replaced the pump or the rack, and they have a lot of kms on them (280k kms)

Fluid is: http://www.penriteoil.com.au/products.p ... oducts=160

The cooler is only a small 7 row cooler

Caveat here: I had the issue with a completely stock power steering setup as well.

The only time i have had the problem is through this tight slalom. No other part of the course showed this issue, or any track days, parking lots anything.

The slalom is straight after a burst to the rev limit in first gear.
 
A

ALLensTRAC

New member
I would recommend to rebuild the pump(OEM rebuild kit is cheap) remove the rack and confirm pretension spec, confirm there is zero fluid in rack boots, drain all lines and flush them with brake cleaner, clean the reservoir out, and then perform a system flush after everything is reassembled. With that many kms and no history of hydraulic system repair this is the best place to start. I've seen a few different vehicles do this in quick switchbacks and I've found debris in rack inlet screens, pump veins, and even coolers. If after all this is done and you're still experiencing it then you might look into a pump upgrade from a different model. This is kind of a long shot as Toyota doesn't list pump maximum capabilities. You would have to compare fluid pressure specs at test rpm to different models.

Oh if you do find fluid inside the rack boots I would recommend replacing the rack vs. rebuilding. I got an OEM reman for about 300$ so it's not pricey.
 
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