| Author | Message | ||
     Brian Vogel Grand Master Username: guyslp Post Number: 1324 Registered: 6-2009 |
My '96 Buick Roadmaster Estate Wagon has recently become incontinent of power steering fluid. Upon inspection it appears that the plating on the "hard line" part of the high pressure hose was defective and it's now rusted and developed a pin hole just above where it enters the steering box. The fittings on the low pressure hose are just as shiny as the fittings on the replacement high pressure hose that recently arrived. This repair seems (key word - seems) to be incredibly straightforward. Remove old hose, fit new hose, run car turning steering from end to end several times to burp the air out of the system. Is there something I'm missing here? The actual instructions go into this elaborate flushing and bleeding procedure. The system has pretty much "self-flushed" since it pushed out the old fluid and is still pushing out the new fluid put in to determine where the leak is coming from. When that was done, and you do the wheel turning bit, you can see the system "burping itself" of air into the fluid in the reservoir. The reservoir is well above the level of the PS pump and it's clear that it's a gravity feed much like that from the brake fluid reservoir to the brake pumps on an SY car. If there's something I'm not taking into account I'd welcome knowing what that is. Brian | ||
| David Gore Moderator Username: david_gore Post Number: 1619 Registered: 4-2003 |
Hi Brian, You are doing everything right, just needs time to fully clear the system of trapped air. The hydraulic circuit is recirculating and not closed like a brake system which requires bleed points to allow entrapped air to escape. I cannot recall ever seeing a bleed point on a power steering box presumably because of this recirculation. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1325 Registered: 6-2009 |
David, Thanks. Just to be clear my comparison to the SY hydraulic system was meant to be limited to the configuration of the reservoir versus pump. Of course, if on ignores "beyond the accumulators" the accumulators are self-bleeding, too. I was completely thrown by these instructions (which are probably more related to flushing than bleeding): A. Disconnect return line at pump end and place in drain pan. Cover tube on pump with flushing cap (included). [Note: it isn't] B. Fill reservoir with recommended fluid. Start engine. C. Cycle steering wheel from side to side (fill reservoir as required) until fluid is clear. D. Stop engine. Remove flushing cap, connect return line hose and re-check fluid level. CAUTION: Extreme care must be taken to completely flush the system. Contaminated fluid will cause unsatisfactory performance. This seems like an incredibly convoluted process and completely unnecessary unless there was some sort of contamination in the existing fluid. Brian, who's also got a pressure sensor as part of the high pressure line since this is a variable assist setup, but that should be a simple item to transfer | ||
| Bob of dorset Unregistered guest Posted From: 188.29.164.117 |
When burping the PAS. Sometimes the oil froths if so leave for 1 hour. Also don't dwell on full lock go to full lock then back off steering wheel a bit. Most cars 3 lock to locks is enough. I like to burp with front wheels off the ground. (Message approved by david_gore) |
