Power steering reservoir is bubbling!

[ian432]

I've recently put a power steering pump back on, after over 3 years barn storage. Can't even remember why it was off now or whether it is the original, lol.
Followed Haynes bleeding instructions to the letter, numerous times now. Just when I think it's sorted, the bleeding stuff bubbles up in reservoir and overflows. Getting tedious now, particularly so now that I've read on here how that's likely to damage alternator.

Steering is good and light, not lumpy or noisy 

So, is air getting sucked in intermittently? All pipes and connections are tight and dry (until it over flows and sprays everywhere!

Rain has stopped play for time being and I've run out of ideas now. 
Any help appreciated, thanks.

[oilyrag]

Are you possibly over-filing the reservoir?

[ian432]

Are you possibly over-filing the reservoir?

The first time I definitely did start off with too much. Since then I've been very careful to follow guidance to the letter. ?

[oilyrag]

Not sure which model you have as there were 2 different reservoirs, one a simple reservoir 'tank' and the other attached to the PS pump itself.  As your van has been sitting for a while it may be that a valve has stuck and pressurised fluid is getting back into the reservoir. If there's somewhere safe to take it out for a spin then I'd suggest driving it - with the possibility that whatever is causing the problem might go away after some regular use.   
Was the van running with a PS pump OK before the lay-up - if the pipes were left 'open' then all manner of critters and muck could have entered .....  .
The O rings on the pipe fittings may allow, as you say, air to enter the system without necessarily leaking any fluids. I seem to recall that they are not 'normal' O rings (maybe square in section?). Might be worth looking closely at them and ideally renewing if you can find replacements.

[ian432]

Not sure which model you have as there were 2 different reservoirs, one a simple reservoir 'tank' and the other attached to the PS pump itself.  As your van has been sitting for a while it may be that a valve has stuck and pressurised fluid is getting back into the reservoir. If there's somewhere safe to take it out for a spin then I'd suggest driving it - with the possibility that whatever is causing the problem might go away after some regular use.   
Was the van running with a PS pump OK before the lay-up - if the pipes were left 'open' then all manner of critters and muck could have entered .....  .
The O rings on the pipe fittings may allow, as you say, air to enter the system without necessarily leaking any fluids. I seem to recall that they are not 'normal' O rings (maybe square in section?). Might be worth looking closely at them and ideally renewing if you can find replacements.

That's a great help, thanks. It's early model with the remote reservoir and was left open. 
It's certainly not as spectacular as it was. Further monitoring and investigation required.

[ian432]

Hmmmm, thought that was solved only to come back to a puddle of PAS fluid. 
Now, when bleeding yet again, turning wheel from lock to lock, I'm hearing grinding noises above the general rattling of the engine.
Can i assume pump is on the way out? I have a spare but with wrong size pulley wheel
?

[oilyrag]

Might be worth a quick check with the front wheels off the ground, no engine, to see if the rack is running smoothly lock to lock.
 If the spare pump turns over OK by hand then maybe try fitting it - the pulley should pull off OK to swap over if the current belt adjuster doesn't allow you to trial it 'as is' .

[ian432]

Doesn't time fly when you're having Berlingo fun?

If anyone is interested, I put the spare pump on and it bled up fine. Yes, the leaking fluid killed the alternator, luckily I found a working spare in the pile of miscellaneous "will come in handy" pile.