[2001 V70 2.4T] Power steering leak from pump and/or reservoir

[prwood]

Over the past week or so, a leak has developed seeping from the power steering pressure line. Specifically, it’s coming from the joint between the pressure line itself and the nut that attaches it to the pump. At idle it produces a steady trickle of fluid, and when you actually try to drive the car and turn the wheels, it dumps nearly the entire contents of the reservoir. See attached photo, red line indicates leak area.

The leak occurs only when the pump is running.

My most recent work with the power steering system was last week when I flipped over the gasket on the power steering reservoir lid to stop a leak that had been showing up there. A few months ago, I replaced the o-ring on the fitting for the high pressure line while I had it disconnected to work on the radiator.

Thoughts I had were: 1. Did I wreck the new o-ring when I installed it? If so, why didn’t it start leaking immediately? 2. Did I get a bad o-ring? 3. Did fixing the leak at the reservoir cap shift a pressure leak to the next weakest link in the chain, and am I simply going to be playing PS leak whack-a-mole until basically the whole PS system is replaced? (The very first job we did when we got this car was replacing the power steering high pressure line, because it was leaking (known when purchasing).

[oragex]

Looks like the locking washer is well in place and prevents the nut from loosening.

I've been removing and replacing the same oil seal for too many times, yet to have any leaks there. So the genuine seal even when it looks beaten up, if it's cleaned well it's good for long time.

Upon driving the car, does it seem to be a lot of pressure when removing the cap?

My only fear is an over-tightened nut, which would shear the threads. The pump is made of alloy so not that hard for this to happen.

Otherwise the seal may be busted

I'm also thinking of a lot of debris blocking the filter inside the reservoir, but less likely.

[abscate]

It is really easy to mess up the Oring there. Pull off the nut and line, pull off the Oring and it should look perfect. Any folds or distortions, replace it.

[oragex]

Good news is it should leak much when removed, just cover the alternator a little

[prwood]

This is what I found upon removal of the pressure line from the pump:

In this photo you can see how it was severed. It was already like that when I pulled it off the line:

I believe this happened due to me improperly aligning the line when I re-inserted it the last time. I think the o-ring just got caught on the side and then eventually tore. Part of the reason for the alignment issue is that I had reattached the intercooler pipe and the oil dipstick tube before attaching the power steering line, which didn't leave me much room to work with. This time, I moved/removed both of those obstructions and inserted the power steering fitting first, ensuring that it was not at an angle at any point between insertion and tightening. Then I hooked the other items back up. There is no longer a leak coming from the pump.

However, I am back to having a leak from the lid on the power steering fluid reservoir. Fluid shows up around the reservoir lid and down the sides of the reservoir, as well as in spots on the right side of the engine bay within a 2-foot radius of the reservoir (power steering hose above the pulley, timing belt cover, top of computer box).

The lid was new as of last summer, and I had flipped the gasket on the lid over just last week in a previous attempt to stop the leak. It seems like the leak only develops when the car has been in motion a bit - I was unable to cause it to leak in the driveway by idling, revving the engine, or by turning the wheel from lock to lock. I don't know if it's relevant, but the fluid that drained when I disconnected hoses was fairly dark, almost black, rather than the cleaner green of the fresh fluid I use (Pentosin CHF 11S). I do hear a slight hiss when I remove the power steering cap after driving for a while. I have no actual issues with steering the car, power steering works well, and there is no noise or squeal during steering in either direction.

Any other thoughts as to what could cause the fluid to come from under the cap?

[abscate]

Neil - I got your PM. No, you can't superglue that O-ring back together and reuse it.

Nice work, P. There is a lot of flow in that container (I once flushed it by feeding in to the reservoir with the hose off - maybe it is splashing up to the lid too much?

[prwood]

Other than the cap, what are the other points of failure on that reservoir? In FCP's how-to video they mentioned something about a valve in the reservoir being loose, necessitating replacement of the reservoir?

Also, I read in one place about possibly upgrading the reservoir and suction hose to the ones used on more recent P2 models (late 2005 and newer) as they are better designed. Anyone tried that? It seems like the main issue is that the molded suction hose isn't an exact fit but can be coaxed into the proper routing.

[800artfreed]

Please look at a recent post titled Power Steering Foam. There is a diverter pipe connected to a brass tube that is inserted into the return hose nipple. That brass tube works its way out and then the diverter pipe fall off. That's what the FCPEuro video is referencing.
This allows for agitation of the PS fluid. I had this condition but it did not cause leaking. It caused noise at the PS pump do to air in the PS reservoir going to the pump. BTW my vehicle is a 99 S70-GLT

I have changed the PS reservoir I got from a old s80. After cleaning it up I noticed that the filler neck is actually a rectangular piece of plastic that is "attached" into the top of the reservoir. Mine has a small separation showing on one side of this seam. I am not talking about the seam between the lower and upper halves of the reservoir. I also now have seepage around the cap area and higher pressure when I remove the cap. Do you think the cap has a pressure limit (why else have the coil spring under the cap) like a coolant cap? Could we be exceeding that limit?

[dlundblad]

Where did you source the o ring? It looks a little too small.

[prwood]

Where did you source the o ring? It looks a little too small.

It was from the Volvo dealer and was the correct part, I just did a bad job of installing it.