Q: R&R of Hydro Strut Top Mount?

[MB_Mike]

Hi all,

I am looking to remove and replace the top mount of my hydropneumatic struts.

In the past when breaking hydro equipped cars for parts, I have found it difficult to remove the 13mm (?) bolt that holds the strut mount to the wheel housing. It has been difficult because the nut retainer that keeps the nut from spinning freely comes loose. When this happend I am required to use a cutting wheel from inside the engine bay to free the strut because there is almost no room for anything else.

In the spirit of full disclosure, this is being done to a W126 rather than a 6.9 but from what I can tell they are mounted almost identical.

Any words of wisdom regarding that darned retainer?

 

[Styria]

Hi MB MIke, that's a nasty one and no easy way to resolve. As you say. it is just about impossible to get a cutting tool onto it, and it is also just about impossible to remove the main hydraulic hose with a conventional tool. I think your method of accessing the caged nut from the engine bay seems the only way, but I still have to look and check if access can be gained to it from inside the engine bay. I haven't looked yet, but I don't think it is possible.

What you could do is to jam some sort of tool into the area where the nut is located to stop it from turning. There is enough space to reach that nut. Use a liberal dose of anti rust/seize propellant and use an impact driver with socket to 'jar' the nut. That could work, but you'll need to stop the nut from turning in the first place. Regards Styria

 

[MB_Mike]

Thanks for the tips Styria. I agree that a good pre-cleaning and spray should help.

When I referred to the cutting wheel from inside the engine bay, I meant that I cut into the strut tower to access the nut (because it was a parts car).

The other thought I had was the order in which things are removed. The last 2 times I did this (both on parts cars) I started with the bottom bolts and worked my way up...I think this allows the strut to move around and the retainer to come loose. This time around I am going to start with this bolt up top, then the large ones at the botom of the strut.

One more thing Styria, you mentioned not being able to remove the hose with conventional tools...How do I remove them? They need replacement as well.

 

[Styria]

No, there is no problem using a conventional open ended spanner - I think the size is 19mm, but you will need to remove the strut first from the body of the car. Can't use a ring spanner because the 'flats' are too close to the body of the strut. Regards Styria

 

[Oversize]

Mike could you take a few pics so the rest of us mortals have an idea of the problem??

 

[WGB]

I assume you are talking about the 13 mm headed bolt at the front edge of the mount vs the 4 x 10mm nuts and bolts.

The bolt is hidden behind the hose in this picture



They simply unscrewed when I removed them from my car leaving the trapped nut intact and ready to be used again.

I assume your cars are rustier so will need lots of penetrating oil and maybe a bit of heat on the bolt head +/- left for a while to soak.

it would certainly be a buggar to replace if it comes loose in the chassis and starts to turn .

Bill

 

[MB_Mike]

Yes Bill, that is exactly what I am referring to. Thank you.

I may have undue concern because the last 2 times I tried this, the cars were in fact rusty or left to sit for extended periods of time.

This time around, I am working on a good, rust free car and hope to not repeat the experience.

I hope to get to this tonight or over the weekend.

Thank you for all of the replies.

 

[Styria]

Well, if one could unscrew the hose from the strut, you might have an even chance of getting to the bolt and caged nut. I have always found, in the past, that those big hydraulic hoses are not easily removed.

Bill, regarding your strut installation - is the small clear plastic bleeder hose in an incorrect position ? I seem to recall that somewhere along the line you have referred to this anomaly, and this may well be what you were referring to at the time. Also, just as a matter of interest, do you clean/paint/detail sections of the underside of your car/s when you are carrying out replacement and/or repair work ? I am just talking about visual improvements. Regards Styria

 

[MB_Mike]

Well it happened. The retainer came loose from the nut and I cannot remove or tighten the 13mm bolt for the strut top mount.

I spent the last 2 hours in the garage stuffing around with it.

I can't believe no one else has had this problem. This is the 3rd time it has happened to me.

Is there any particular procedures listed in the workshop manual as to how to do this properly?

 

[WGB]

Styria - 1) you are correct about the bleed hose being in the wrong position and it is mentioned in my initial posting.

The final position for the bleed hose is controlled by the final position of the top cap and I screwed both top caps up with red loctite before I realised that it was supposed to be at the front.

As there was plenty of hose to connect and nothing fouled I left it as it was rather than open the top caps again.

2) I have nerver painted under the car as it seems relatively virgin like and is very intact. I have considered it and may do it in the future but the preparation would have to be absolutely precise or it would rapidly become a pile of peeling paint.

Thought for the future though.

Bill

 

[Oversize]

I assume this is the bolt in question?





If it was me, I'd clean the area, remove the hose and then try tac welding the nut in place... Or try a tiny metal (probably fabricated) wedge.

 

[MB_Mike]

Hi Mark,

Yes that is the bolt in question. The trouble is, there isn't nearly enough room to tack the nut with a welder or much of anything really.

I stopped by my mechanic the day after the nut let loose and he insists that a simple hobby sized rotary tool with a cutting wheel will remove the #8 hardened bolt. I am sure he knows better than I do but I haven't gotten around to trying this yet.

Another case of "While I am in there..." has struck and I am considering refreshing all of the front end components, upper and lower control arm bushes, ball joints, on and on.

I will report back with my findings.