C70: How to flush power steering fluid?

[MikeS100]

Hi all,

Am I correct in thinking the CHF used in the power steering system should be green in colour? I've just checked my C70, didn't think of it before, and the fluid that's in there is red. Presumably this was topped up by the garage I bought it from 2 weeks ago and they have just used normal ATF. It looks quite fresh, like it hasn't been in there long. Would that have done any damage to the seals in that time? And what's the best way to flush it through, take off the return to the reservior and then just keep the reservior topped up as someone else works the steering to push it through? Any ideas how much CHF I should buy to make sure I get a proper flush through?

Thanks

[Paffel]

Can you get to the rack to undo one of the banjo bolts on it?

[MikeS100]

Originally Posted by Paffel

Can you get to the rack to undo one of the banjo bolts on it?

I'm not sure is the honest answer, I don't even know where I would find them! Where should I be looking?

[Paffel]

Before you take my word, I'd like a second opinion on my advice below, if someone can help?

There's 2 ways you can flush it really - one is to use a baister/suction syringe to pull the fluid out of the reservoir, then top up with fresh, flick on motor, turn steering lock to lock, turn off, and repeat - however if you've potentially got mixed types in there you may want to do a full refresh.

2 pipes will go from the reservoir to the rack - one for supply and one for return. By undoing the (return) bolt on the rack, you can drain the old fluid out. Turning the wheel side to side (WITHOUT turning it on) will help move any fluid. Put the bolt back in, and top up the reservoir with fresh fluid, until its at MAX.

Turn the wheel from side to side again, to help any air escape. Top up back to MAX, then turn car on and repeat. Turn car off and recheck level.

If you turn the car on when the bolt is undone, the fluid will go down very quickly. And it will likely make a mess.

By the way, ATF fluid is awful. It smells, has a horrible texture and it can get everywhere if you're not careful. I've just done the rack on the 740 and i'm hoping I don't have to do it again anytime soon, purely for the ATF fluid!

[MikeS100]

Thanks for that, sounds like a good plan and what I will probably end up doing. I'm going to pick up a part from my local Volvo main dealer in the morning anyway so I will ask them how much CHF I need, but if anyone can give me an idea on quantity I would appreciate it.

[MikeS100]

Anyone know if Halfords CHF is the same/just as good as the Volvo stuff? It's a bit cheaper and as I'm probably going to be needing a fair few litres of the stuff I might go for that rather than the genuine Volvo stuff if it's all the same.

[hjdlatd]

Check your owners manual but i'm sure one litre is sufficient.

[MikeS100]

Thanks. The dealer said just over 2 for a full flush if it's had the wrong stuff in there. First one to flush through and then second one to top up. They actually gave me a third bottle for free though and a discount on the auxiliary drive belt I needed. I didn't ask for a discount, but he remembered me from earlier in the week and all the trouble I had when the sold me the wrong thermostat so offered me the discount I was well happy with that.

[MikeS100]

All done. Start to finish including getting everything ready and tidying up at the end took 35-40 minutes I spoke to the technician at my local volvo dealer and he said when they do a flush they just disconnect the return hose off the reservoir and then keep topping up the reservoir while someone turns the steering so this is what I did and it worked perfectly. I used 2.5 litres of CHF just to make sure but may have got away with less. It was running out a nice green colour at the end. I jacked the front up as well so the wheels could turn easily without having to run the engine or wear out my tyres. All in all I'm pleased with a job well done

[mattbibby]

Thanks for the advice here.

I flushed my 04 V70 by disconnecting the return hose (put it in a bottle and tape the nipple on the reservoir shut) and topping up the reservoir as suggested, while an assistant ran the engine and turned the steering wheel. . It pumps very quickly so an assistant is definitely required! I used 2 litres and I don’t think it would be possible to do it with any less using this method. The fluid is available at £10/litre from my local car parts shop.

The stuff that came out was dirty brown, then dark red, then dark green, then lighter green. Hopefully this will improve the slightly notchy steering.

Thanks again to everyone for their help!