Mechanics

POWER STEERING INTERMITTENTLY INOPERA

1990 Volkswagen Jetta

Steering problem
1990 Volkswagen Jetta 4 cyl Front Wheel Drive Manual a lot miles

Power-assist seems to drop out intermittently but frequently. The car drives like a 1968 Bronco in parking lots, but it's much better at speed (no surprise). There is minimal noise involved -- no belt squeal (though I did replace all three drivebelts because they looked to be from the late Cretaceous, and there was some glazing on the PS/WP belt). The only sound is a slight hissing noise, audible over road noise but nothing else, apparently from right in front of the driver.

All this suggests a bad rack to me -- internally leaking. Except changing the drivebelt made the drop-out less frequent. I don't see how that's possible.

These parts are outrageously expensive for this vehicle, so I don't really want to guess. And my pressure gauges are designed for crankcase oil and won't be very happy with the 80 bar or so the PS pump puts out. Is that (or a shop) my only option? Is a pump rebuild kit a sensible option? I wouldn't have bothered on my Ford, but I can get a reman Ford PS pump for $50 instead of $200.

I'm confused. How can I narrow this down?
Avatar
MAKG
January 12, 2009.




OVERHAUL
STEERING GEAR
Before disassembling steering gear, check output and system pressure. When overhauling steering gear, always use all parts in Repair Kit (811 498 020 ). Always use new self-locking nuts and "O" rings. Use exploded view of steering gear to assist in overhaul. See Fig. 1 .
On all models, manufacturer recommends replacement of steering gear if pinion or piston-rod seals are leaking.

SYSTEM PRESSURE TEST
Install Pressure Gauge (US1074 B ) between pressure hose and pressure pipe of valve housing. Open pressure gauge valve. Run engine at idle. Turn steering wheel lock-to-lock several times.
Pressure should be 1100-1200 psi (77.83-84.36 kg/cm2 ). If pressure is not within limits, check pump pressure. If pump is good, replace steering gear.
PUMP PRESSURE TEST
Install Pressure Gauge (US1074 B ) between pressure hose and pressure pipe of valve housing. Start engine and let idle. Close valve (for no longer than 5 seconds). On Vanagon, pressure is 1668-1740 psi (117-122 kg/cm2 ). On all others, pressure is 1100-1200 psi (77.83-84.36 kg/cm2 ).
If pressure is not to specification, check limiting valve by inspecting bores in valve and piston for obstructions. Ensure piston moves freely in housing. Install new valve if necessary.
LEAK TEST
With engine idling, turn steering wheel to full lock and hold in position. Inspect all connections and tighten if necessary. If leak shows at steering pinion, replace housing seal and both intermediate cover seals.
If pinion shaft seal is leaking, fluid has entered gear housing. Check for fluid by loosening outer clamp on right steering boot and pushing boot in. If seal is leaking, disassemble steering gear and replace all seals.


http://www.2carpros.com/forum/automotive_pictures/266999_steer_3.jpg


Dave H
Jan 12, 2009.


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