940 suspension question

[moetheshmoe]

Has anyone else noticed this? My 1993 940 Turbo wagon needs some new struts and shocks. As far as the struts I've tried Monroe, KYB, Bilstein 4's and Sachs(twin tube gas). They seem capable, they compress and rebound ok, just at different pressures. But the shocks are different. The Monroes and the Bilsteins compress ok but they don't rebound, you have to pull them back to their original length. Does that mean they've lost their gas? As far as Sachs, the only gas model left is their monotube(performance) model and it does rebound on it's own. I'm wondering why that is?

 

[classicswede]

The ones that push back up are oil shocks with added gas pressure to aid oil stability
The ones that do not push back up are basic oil filled ones

 

[moetheshmoe]

Yes I'm aware of that but the Bilstein's and the Monroe's are both advertised as twin tube gas shocks. But they don't rebound. The Bilsteins are fairly new and the Monroes are brand new.

 

[classicswede]

Yes I'm aware of that but the Bilstein's and the Monroe's are both advertised as twin tube gas shocks. But they don't rebound. The Bilsteins are fairly new and the Monroes are brand new.

in that case they are faulty or wrongly described

 

[moetheshmoe]

Can the Bilstein's be re-gassed?

 

[classicswede]

Can the Bilstein's be re-gassed?

B4's no, B6's you could send them off for repair but 99% you are looking at B4's

 

[conehead]

I thought the same thing when I got my basic oil filled and they didn't push back, like hey are these bad? But then, Imagine pushing your hand backward and forward in water. Good amount of resistance. That's basically all a shock is, in a crude sense, just something to add resistance, so it doesn't really matter if the shock pushes back, since your springs can do that job. that said, if you bought shocks advertised as ones that should push back, I'd give them a call and ask them what's up. If I remember correctly, the gas filled shocks that push back are just meant to keep the oil under pressure, thus helping stop the oil from foaming up and losing some of it's stability, so they pushing back is likely just a side effect of the gas, not necessarily a design feature.

 

[moetheshmoe]

That makes sense, cuz I just sent my Monroes back, since they we're under warranty. And just received a brand, spanking new pair and they do the same thing - no automatic rebound. So maybe the Bilstein B4's are ok too?

 

[classicswede]

No, both are not working
What is the Monroe part number you are using?

 

[dl242gt]

Are these the Monroe Sensa Trac struts? They are NOT gas struts. Monroe also sells a non gas charged stock replacement. I've never seen gas Monroe shocks for a Volvo rwd car. Although stock fitment on a 9 series car is a gas charged shock.

If a gas charged strut don't push back. Then it's lost the charge and is ready to recycle.

 

[moetheshmoe]

No, both are not working
What is the Monroe part number you are using?

They're OE Spectrums #5930, not Sensa Trac's. And let me add this - the Monroe and Bilstein front struts that go with these rear shocks are also twrin tube gas charged and they do rebound on their own. What are the odds that every Monroe shock and every Bilstein shock that I bought won't rebound but the matching struts do rebound? Am I cursed, since the odds of this happening are probably greater than winning the lottery?

 

[jerryc]

IME, all the Bils, KYB, Sachs I have had do push back out/up. Monroe I can't speak to. I do have some TurboGas Sachs fronts for sale, approx 2k mi.