996 2001 no power steering

I removed , drained and reinstalled the power steering pump. Now there is no power steering. The fluid is full and I have turned the wheel lock to lock several times and still no luck. Is there a way to check if the pump is bad... i see no leaks...

Quotes source post: 12064750

Is the serpentine belt routed correctly? Does it have the proper tension? Not much experience trouble shooting power steering issues. A possible test of the pump would be to remove the belt and turn the pump by hand -- in the right direction -- and carefully observe the fluid in the power steering tank to see if it is flowing out the return line into the tank. Trouble is by hand may not be fast enough. You'll just have to try this -- unless you or someone else comes up with a better idea -- and if you believe by hand is not fast enough to see if you can rig something up where you can turn the pump by an electric drill motor. You shouldn't have to spin the pump that much faster not even close to idle engine speed just to confirm fluid is flowing. Now even if fluid is flowing all this means is well, fluid is flowing. To work the power steering rack a valve has to close in order to route high pressure fluid to the proper side of the rack piston to push the rack in the right direction. The other side of the piston has to have a passage back to the low pressure side of the power steering hydraulic system to allow any fluid on that side to escape. That valve mechanism is a pretty trouble free piece of kit. I would be surprised if it was bad. Which leaves pressure. If there is a failed -- stuck open? -- high pressure relief valve even though fluid is flowing it is not under sufficient pressure to exert any real force against the rack piston. If there is a pressure test point some where in the power fluid system I'm not aware of it. Might be one located on the power steering pump. Be careful. Modern power steering systems work with a power steering fluid pressure of 1000psi. If you find a pressure test fitting you better know what you are doing. Pentosin at any pressure is not a fluid to take lightly. At 1000psi it is downright dangerous. Oh, I forgot. If you manage to make it this far there is the possibility the rack piston is leaking and high pressure fluid is being routed to the proper side it is just flowing past the piston and to the other side. There will of course be no power assist.

If it operates on the same principal as the brakes, then there must be a bleed nipple. I suggest you have let air into the system which needs to be bled out as you would the brake system. Just a thought.

It really begs the question - why did you remove the power steering pump in the first place? Normally they don't fail completely. Mostly leak at the seal. Since you have introduced air into the system, it may take many lock to lock cycles to "burp" the system. It is a long way from the power steering pump to the rack, and back. Suggest you jack up the front of the car to relieve the strain on the steering rack and cycle through the lock to lock many times, holding in the left and right position. This while the engine is running. Leave the cap off the pump and constantly check the fluid level. To the best of my knowledge there is no bleed valve anywhere on the system.

Thank you ... I will pull the belt and lines and see any fluid movement ... moving the pulley.

You bring up a good point. While I read the system was drained I just assumed it was bled properly afterwards. However, as you pointed out this doesn't have to be the case. A full lock to lock turn of the steering wheel could purge the system of air, though if there is too much air in the system the tank level could drop enough to allow air back into the hydraulic system. There is also the concern about the pump running low on fluid as the air is replaced with fluid. One could alleviate this I guess by turning the wheel say just half way to full lock in one direction and check the fluid level and top up if necessary then turn the wheel the rest of the way and again check the level, then repeat the steps turning the wheel in the other direction. The above is just a WAG. I don't recall ever coming across a power steering hydraulic system bleed procedure. I wonder how the techs do this when they replace a power steering pump? Or for instance when my Turbo's steering fluid tank was replaced to quiet a noisy/bad valve? (Think I'll ask.) Also, I like your idea of getting the front end in the air so the tires are not making contact to reduce the amount of stress on the hardware as the steering is turned lock to lock.

Quotes source post: 12065451

+1 and no, there is no bleeder valve.

Ok I have the power steering bleed process I think. I asked a tech about how to bleed this system. He said it is simple, almost. After buttoning the system up fill the tank with fluid and start the engine and let it idle. The pump will run and circulate the fluid. As the pump runs more fluid will have to be added. He didn't say this but I will: Watch those eyes! My fear is the fluid might splash out as the circulated fluid comes back from having passed through the system and having encountered air pockets. Kind of like a garden hose does when one first turns on the faucet to which a garden hose is connected. At some point the power steering fluid level will not drop as the system -- well some of it -- gets full of fluid. However, the system is not completely full of fluid. Air pockets remain in the rack. To get rid of these the steering wheel has to be turned full lock first one way then the other. The tech didn't offer that the car had to be in the air and I didn't ask him specifically about this. Now this is where it gets a bit tricky. The tech said that doing this turning the steering wheel lock to lock business will likely cause the fluid to foam as it is routed to the rack piston areas with air in them. The problem is if you keep the system running this fluid with air in it will be pumped through the system and one will never get the air out of the system. Once the engine is shut off the fluid -- wherever it is -- will over time release this air and pockets of air will (re)form in the system. So, the tech said when the fluid gets foamy/frothy to just shut off the engine and let the car sit a couple of hours to let the fluid cool down and to lose its air. Making sure the fluid level in the reservoir is ok then start the engine and with the engine idling turn the wheel lock to lock or stopping at the first signs of frothing and foaming. When this appears then once again shut off the engine and let the fluid cool down and lose any air. Repeat the above until the fluid comes out into the reservoir with no signs of air, foam, or froth. As I mentioned above watch your eyes so you do not get fluid into them. Have some clean tap water on hand to rinse away any power steering fluid that might splash or spill out and in doing so get on rubber, paint, plastic, or even metal. In the case of Porsche power steering systems the power steering fluid is Pentosin and while I have no problem with Pentosin as a power steering fluid it is not a nice fluid to spill or get on anything outside of the inside of the power steering hydraulic system. My other caution would be to when you shut off the engine to avoid leaving the steering wheel cranked way over. Try to bring it back to nearer center before shutting off the engine. This may not matter but as a matter of principle I just prefer with the engine running to avoid having the wheel cranked hard over for any more time that is absolutely necessary and I do not like to park the car with the wheels cranked over too much from the good old straight ahead position. Let me also add that even after the above, with no more foamy fluid coming into the reservoir that one believes the system is completely filled with fluid, one must check for any leaks from any of the power steering fluid connections or hoses. Also, I think it would be a good idea to keep an eye on the power steering fluid level for a while just to make sure that no hard to reach air pockets are finally reached and the fluid level drops. I doubt it would get dangerously low but better safe than sorry.

Thanks for sharing the tips Macster. The foaming part is quite interesting.

The system does not need to be bled, the pump and overflow valve are the highest points of the system, Issue causes: belt is heavily slipping, vastly incorrect fluid used (CHF11S is correct) or is too low.., pressure line failed or pump or rack has failed internally. A cavitating pump as Macster talked about(foaming fluid) is very noisy...

Quotes source post: 12094772

Agree with an untouched power steering system. In this case though the owner reported he removed and drained the system -- it was not stated why this was done/necessary -- and then the system was refilled with fluid. It is not clear that the lack of steering is related to any air in the system, but the question of how to refill/bleed this hydraulic system came up. While there is no bleed valve the system has to have all the air removed and curious about how this might be done with no bleed valve I asked and what I was told I posted above.

Quotes source post: 12095803

I have pumped/purged the P.S. system...it is self-bleeding(the reservoir has a bleed valve built-in) , do an initial fill on system/reservoir, then run engine and continually add fluid until fully topped-up I will be doing the same fluid flush on a 996TT in next few weeks.