V70 Steering Rack replacement: some questions

[Radler]

Hi folks.

The steering rack on a friend's V70 has given up and needs to be replaced. It poured all the fluid and at the moment there's no power steering.

This is a V70 from 1998 he bought just some months ago. Back then the steering already made a lot of noise, but he assumed it just needed a new pump and the price of the car was good. The steering pump was replaced last month at a workshop and just last week, while driving on the highway, he was left with no power steering. He took it back to the workshop and they told him the steering rack has broken and needed to be replaced.

Since the quote they gave for the repair is completely over the moon, and since my friend was not too happy with the workshop the first time, he asked me if I think we could do it ourselves. I've had two V70's myself, and never had to replace the steering rack, but with the workshop prices here in Germany I always think I can f*ck up multiple times doing the job on my own before making that price worth it. So of course I said yes.

I've been watching videos on Youtube, reading threads on this and other forums and also read one PDF that a user uploaded here some years ago. All in all it seems doable (until a bolt snaps, that is), but I still have a couple of questions:

1) Part number. I've read that the last number on the Product ID (see https://www.ipdusa.com/Articles/524/) identifies the steering rack. I've also read people saying there's no real way to know which rack your car has until you take the old one out. This is relevant, since we'll do the job in a DIY workshop where you can rent a lift, and getting the wrong part would mean having to leave the car there for a couple of days until the new part arrives.

2) To hold the engine we have two options: an engine bridge or a gearbox jack. The first one seems like the best option, since it doesn't get on our way under the car, but the gearbox jack is more precise when lifting/lowering the engine since it's hydraulic.

3) How to flush clean the steering system? I suspect the old steering pump being responsible for the steering rack failure. I've heard of bad pumps releasing tiny metal bits into the fluid that end up clogging the rack. If that's the car, we do not only need to replace the rack but also flush all those metallic particles. Would it work if we disconnect the return hose at the pump and work the steering with the engine running while we keep pouring fluid into the reservoir? Could we use some cheaper fluid like for this job?

4) Refurbished brand. Since the price of an original rack is unaffordable, we'll go for a refurbished one. I've read in some threads that there are certain brands to be avoided. Any concretely that you'd recommend?

5) Any other piece of advice would be much appreciated.

I'll try to marinate the bolts underneath with the old ATF-Acetone salsa. I'll also try to wash the lower part of the engine to avoid dripping. Torque specs should be found on Haynes manual, I guess.

Thank you very much.

[abscate]

There were two brands of rack used on the cars, TRw and SMI. You can use either one, but you have to replace both sets of inner and outer tie rods as those are not compatible across the two brands. It’s usually worthwhile to buy a rack with these installed as they are often frozen on, and near end of life anyway.

Get the engine bridge to hold it up while you drop the subframe. Order both power steering pump lines from a place that lets you return them, those can really get stuck m in which case cut them off

You can flush the pump with atf and filter it with about four liters of fluid

Use new Volvo bolts on the rack, they are cheap.

I’ll link to the discussion on power steering rack brands

[MoVolvos]

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Didn't mention anything about diagnostics by the shop or yourself on the problem? Try flushing the system first and see what you find. Also, seems kind of odd that with old pump you still had power steering but the new suddenly gave out? Could it be the new pump?
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[Radler]

There were two brands of rack used on the cars, TRw and SMI. You can use either one, but you have to replace both sets of inner and outer tie rods as those are not compatible across the two brands. It’s usually worthwhile to buy a rack with these installed as they are often frozen on, and near end of life anyway.

Get the engine bridge to hold it up while you drop the subframe. Order both power steering pump lines from a place that lets you return them, those can really get stuck m in which case cut them off

You can flush the pump with atf and filter it with about four liters of fluid

Use new Volvo bolts on the rack, they are cheap.

I’ll link to the discussion on power steering rack brands

Recently I replaced an inner tie rod in my current V70 and they sent me the wrong one, with a thinner diameter of the threaded part. I guess what you mention about TRW and SMI must be the reason.

Do you know the size of the rack bolts you mention?

[Radler]

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Didn't mention anything about diagnostics by the shop or yourself on the problem? Try flushing the system first and see what you find. Also, seems kind of odd that with old pump you still had power steering but the new suddenly gave out? Could it be the new pump?
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That's some nice video. Thank you.

I guess the reason for losing power steering is that a bad steering pump can still get the job done, even if underperforming, but if a rack gets clogged then there's no hydraulic pressure acting on the steering, just the mechanical components operated by the steering wheel. Correct me if I'm wrong.

In any case, according to my friend all the fluid poured out through the rack, so there can be no power steering without fluid. If the fluid went out due to a bad seal or if the seal went bad due to inner pressure built up at the rack due to a clogged conduct I do not know. Actually, I still did not have a chance to take a look at the car since my friend is away these days.

[MoVolvos]

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Didn't mention anything about diagnostics by the shop or yourself on the problem? Try flushing the system first and see what you find. Also, seems kind of odd that with old pump you still had power steering but the new suddenly gave out? Could it be the new pump?
.

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That's some nice video. Thank you.

I guess the reason for losing power steering is that a bad steering pump can still get the job done, even if underperforming, but if a rack gets clogged then there's no hydraulic pressure acting on the steering, just the mechanical components operated by the steering wheel. Correct me if I'm wrong.

In any case, according to my friend all the fluid poured out through the rack, so there can be no power steering without fluid. If the fluid went out due to a bad seal or if the seal went bad due to inner pressure built up at the rack due to a clogged conduct I do not know. Actually, I still did not have a chance to take a look at the car since my friend is away these days.

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Not sure how a rack went from under performing to all of a sudden complete fluid lost? The phase in between is the pump installation so perhaps under performing repair? By replacing the pump you should have quite of bit of new fluid. If I were doing the work all the fluid should have been replaced.

I don't buy the clogging theory as if I were the mechanic and I encountered that much metal debris, which is unlikely, I would have let the customer know. The holes for fluid control are quite large and no where near the size of valve bodies in the transmission.

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[foggydogg]

Since the fluid has escaped the only solution is to replace the rack.
As abscate mentioned use the bridge to hold the engine/transmission; they stay in place while you drop the subframe. The bare subframe isn't heavy, just awkward; two people can handle it easily, or a floor jack with a board across can help hold it in place going back. Some people remove the rear bolts but just loosen the front ones and let the cradle drop far enough to get the rack off, less suspension bits to deal with. Drop it a little first to get access to the nuts on the hard lines, take care here, they are soft. Don't use an impact gun on the nuts holding the rack to the cradle, it may cause the splines on the studs to spin and cause ... Aggravation.
If both hoses survive removal from the rack, take them loose from the pump and blow them out with air, then use brake clean - or the Euro equivalent - blow them out again. Reconnect the pressure hose, flush with some fresh fluid, and reassemble.
It isn't a technical challenge, just time-consuming. Patience is your friend.
Others from the EuroZone may have to offer advice on rebuilt brands, our experiences over here may not travel well.

[MoVolvos]

Since the fluid has escaped the only solution is to replace the rack.
As abscate mentioned use the bridge to hold the engine/transmission; they stay in place while you drop the subframe. The bare subframe isn't heavy, just awkward; two people can handle it easily, or a floor jack with a board across can help hold it in place going back. Some people remove the rear bolts but just loosen the front ones and let the cradle drop far enough to get the rack off, less suspension bits to deal with. Drop it a little first to get access to the nuts on the hard lines, take care here, they are soft. Don't use an impact gun on the nuts holding the rack to the cradle, it may cause the splines on the studs to spin and cause ... Aggravation.
If both hoses survive removal from the rack, take them loose from the pump and blow them out with air, then use brake clean - or the Euro equivalent - blow them out again. Reconnect the pressure hose, flush with some fresh fluid, and reassemble.
It isn't a technical challenge, just time-consuming. Patience is your friend.
Others from the EuroZone may have to offer advice on rebuilt brands, our experiences over here may not travel well.

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Neither the OP, the owner has said nor the mechanic has told them where and how the fluid loss occurred on the rack. Should get a second opinion before throwing parts at a problem that has not been fully diagnosed. Not sure if the PW has O-Rings and if so could it have been sheared during installation of the pump?
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[MoVolvos]

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Not sure about Germany but here in the States there are laws protecting the consumer on auto repairs. Shops must provide a diagnosis and a quote before work can begin. Can't just say you need a rack without providing a reason.
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[Radler]

Not sure how a rack went from under performing to all of a sudden complete fluid lost? The phase in between is the pump installation so perhaps under performing repair? By replacing the pump you should have quite of bit of new fluid. If I were doing the work all the fluid should have been replaced.

I don't buy the clogging theory as if I were the mechanic and I encountered that much metal debris, which is unlikely, I would have let the customer know. The holes for fluid control are quite large and no where near the size of valve bodies in the transmission.

I can say something similar happened to me in a car in the past: the previous owner may not have known that AC systems work with gas and that this needs to be refilled from time to time, so he just kept using the AC even though the system was already empty. The result was the AC compressor working empty for years. After I bought the car I replaced the AC relay, the AC pressure switch, the AC compressor, the AC condenser, etc., and the AC was still not working even when all the electrics were fine. The mechanic already alerted me when replacing the condenser that he found metal bits in it, and that it may have been due to the damaged in the compressor after working with an empty system. At the I had to give up on it, since the next step would be removing the AC hoses checking one by one if they were clogged with metal debris: this would have been a big job since it was a van with a second AC blower at the back.

I would guess my friend's mechanic did not pay much attention to this, since replacing the pump is pretty much straight forward and they normally pour these fluids onto a big container, so he would not have seen the metal bits anyway. But that's just a theory, of course.