Power Steering system creates air pressure
10-18-2015, 08:17 AM
#1
Power Steering system creates air pressure Hey guys
lq4 with a cam in a 98 m3
Factory f body power steering pump, factory f body pressure line.
So its the factory f body pressure line going to the factory BMW pressure line with a JIC style coupling the 2 together. (brought the f body line and BMW line to a hydrualic shop and had fittings crimped to them to be able to join them.)
The return line just comes straight from the rack, through the stock BMW cooler (just a coiled hard line) and straight back to the F body reservoir
The lines are very similar sizes. Very similar.
But my car has been REAKING like atf. Like un driveable. So initially i start looking at the trans. No leaks at all.
But i noticed last night while it was at temp and running, i can see air pressure leaking from the F body steering cap with fluid bubbling out with it.
Steering works mint, never has given me any reason to think there was anything wrong.
So i was wondering what would cause there to be air pressure at the reservoir or cap?
lq4 with a cam in a 98 m3
Factory f body power steering pump, factory f body pressure line.
So its the factory f body pressure line going to the factory BMW pressure line with a JIC style coupling the 2 together. (brought the f body line and BMW line to a hydrualic shop and had fittings crimped to them to be able to join them.)
The return line just comes straight from the rack, through the stock BMW cooler (just a coiled hard line) and straight back to the F body reservoir
The lines are very similar sizes. Very similar.
But my car has been REAKING like atf. Like un driveable. So initially i start looking at the trans. No leaks at all.
But i noticed last night while it was at temp and running, i can see air pressure leaking from the F body steering cap with fluid bubbling out with it.
Steering works mint, never has given me any reason to think there was anything wrong.
So i was wondering what would cause there to be air pressure at the reservoir or cap?
10-18-2015, 11:15 AM
#3
On The Tree
Height of the steering reservoir above pump.
Must have large hose from pump to reservoir.
When pumps suck they tend to cavitate, so pump reservoir needs be able to flood pump inlet at a rate equal to the full output.
Reservoir on the pump is best way. Or (short) 3/4 or 1" hose with good drop to pump.
Also Best to have reservoir in front of (and above) pump so gravitational forces under acceleration do not pull oil away from pump.
Must have large hose from pump to reservoir.
When pumps suck they tend to cavitate, so pump reservoir needs be able to flood pump inlet at a rate equal to the full output.
Reservoir on the pump is best way. Or (short) 3/4 or 1" hose with good drop to pump.
Also Best to have reservoir in front of (and above) pump so gravitational forces under acceleration do not pull oil away from pump.