Power Steering Pump not Boosting at Idle...

[WildBob]

I understand if a PSP goes bad it wouldn't work at any RPM...but this behavior is strange to me...

At idle, the pump is not boosting the steering, but just off idle and throughout the RPM range it is working just fine...including the boost reduction as I gain speed.

The symptom appeared after I did a donut from a standing start to reverse direction from the shoulder...hit the rev limiter in first as I whipped her around and straightened her out and when I pulled over a minute later the power steering wasn't working at idle.

Is it possible that an air bubble is stuck in there or is the pump just at the beginning stages of failing? It's noisy when it is set to full lock when stopped and when trying to maneuver at low speeds.

Any steering pump experts out there?

The more important question...will I have to drop the chassis from the body to change the pump if bad? It's TIGHT in there! I certainly hope not!!!

[Silent1]

is it not a slipping belt that at idle isn't gripping enough to turn it quickly enough to make pressure?
So a failed tensioner if it has one, otherwise the belt has stretched/partially failed.

[WildBob]

Silent1 said:

is it not a slipping belt that at idle isn't gripping enough to turn it quickly enough to make pressure?
So a failed tensionfer if it has one, otherwise the belt has stretched/partially failed.

Ahhhh...good catch...I will definitely be checking that...and rebleeding the pump just in case the hose judder issue introduced aeration into the system...my car didn't get the hose replacement...

The belt is an easy replacement...the tensioner I don't know yet...

[yourtheguy]

A while back someone had a similar problem, but i can't remember the outcome.
I would say that the pressure releif valve has gone weak or stuck open a small bit due to being held on full lock.
If the pump is duff i'm sure with a bit of research you might find it's fitted to a ford or jag.

[mcm66]

My car did that, just on idle for a little bit then cleared. Aston Martin put an additive into power steering fluid, seem to remember there was a service bulletin on topic. Anyway, seemed to do the trick.

[mikey k]

WildBob said:

The symptom appeared after I did a donut from a standing start to reverse direction from the shoulder...hit the rev limiter in first as I whipped her around and straightened her out and when I pulled over a minute later the power steering wasn't working at idle.

Is it possible that an air bubble is stuck in there or is the pump just at the beginning stages of failing? It's noisy when it is set to full lock when stopped and when trying to maneuver at low speeds.

IIRC one of your fellow country men did exactly the same with similar symptoms and ended up replacing the steering pump
Try a search on here and 6speed

[WildBob]

Thank you all for inputs...indeed I found a thread (Doughnuts Bad!) and the pump was knackered in his case. There's even a video of a brand new Benz doing donuts and getting the same result...no more donuts for this guy!

It looks like a doable DIY project, but I will get a quote from the dealer just for grins. As far as the pump being on a Ford or Jag, you can bet I will be digging deeper on that.

[Johnchris]

Anyone know how long takes to change PSP vantage v12 2009 aston