Steering box leak on my 90

Noticed my steering box seems to have recently developed a bit of a wet patch on the underside and a slight drip of rusty looking fluid on the floor this morning

The black power steering reservoir seems to be full though and at the normal level.

Is it worth trying to use some of that stop leak stuff? A few folks have said they have had success using the Wyns power steering Leak stuff. If so where do I put it? Feels wrong putting it in the fluid tank and hoping for the best, be worried it blocks up the piping hmm.

Also is it just the power steering reservoir level to be concerned about? Does the box have any other sort of oil inside it?

Something online for a series 3 suggested the box itself is full of ep90 too, but then other postings differ so I am a bit confused here. Since the Series 3 has no power steering i assume the system is quite a bit different too

Do i just need to monitor the level inside the black reservoir full of red steering fluid on the front corner of the vehicle anything else?

You don't say what model/year you have. Power steering fluid only, no EP90 The red stuff is all that is in there.
A weep is not uncommon, keep reservoir toped up. Is leak from output steering arm? Seal here can be replaced with box in situ but requires removal of the arm [ can be hard to do, check search function] Changing seal can be a bit difficult. I have made myself a tool to press in new seal.
If there is any side to side movement in output shaft new seal will not be worth it and box needs reconditioning.
Sounds like you just need to keep an eye for now, res level and little loss.

tottot said:

You don't say what model/year you have. Power steering fluid only, no EP90 The red stuff is all that is in there.
A weep is not uncommon, keep reservoir toped up. Is leak from output steering arm? Seal here can be replaced with box in situ but requires removal of the arm [ can be hard to do, check search function] Changing seal can be a bit difficult. I have made myself a tool to press in new seal.
If there is any side to side movement in output shaft new seal will not be worth it and box needs reconditioning.
Sounds like you just need to keep an eye for now, res level and little loss.

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Thanks sorry its a 1999 T Reg 300 TDI 90 CSW

Also just to add just before full lock there is a bit of a dead spot (side to side) movement when turning right just before hitting full lock, but there is no play or anything when driving normally, when wheels are straight and true if that means anything?

It apparently had a recon box fitted in October 2019 (according to paperwork I had) so it doesn’t seem to have lasted very long. Unless four years is about normal?

Although suppose the box fitted could have been junk?

Not sure what you mean by "dead spot" If slack in steering wheel at full lock that is normal. One should not hold power steering hard on full lock [ same for every vehicle ] Can not say "how long", depends on miles, type of use, quality of rebuild.

tottot said:

Not sure what you mean by "dead spot" If slack in steering wheel at full lock that is normal. One should not hold power steering hard on full lock [ same for every vehicle ] Can not say "how long", depends on miles, type of use, quality of rebuild.

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Yeah its just a little bit of floppy movement just before hitting full lock but only when turning right weirdly its always been present that though

Are you sure stops are correctly adjusted.
I have removed box twice to change seals must be tricky doing it on the vehicle.
Stop leak worked for a while but didn't fix it.

I had a leaking box coming up to a mot. I had read that a capful of brake fluid can stop leaks. I got two more mot’s out the box before changing it.

Anaconda said:

Are you sure stops are correctly adjusted.
I have removed box twice to change seals must be tricky doing it on the vehicle.
Stop leak worked for a while but didn't fix it.

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Where do you put the stop leak in the plastic fluid tank itself?

Def90man said:

I had a leaking box coming up to a mot. I had read that a capful of brake fluid can stop leaks. I got two more mot’s out the box before changing it.

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And did that work ?

ryan_1993 said:

Where do you put the stop leak in the plastic fluid tank itself?

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Yes, that's the only way to get fluid . We'll, only sensible way.

D1Nut said:

And did that work ?

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It might work to an extent but as mentioned you are going to have to fix it properly at some time, unless you sell it.
It's a messy job but not classed as difficult.
Britannia Restorations on YouTube has a good how to video.

Anaconda said:

Are you sure stops are correctly adjusted.
I have removed box twice to change seals must be tricky doing it on the vehicle.
Stop leak worked for a while but didn't fix it.

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I made a little two tube tool that presses the seal into place, it holds seal square and uses the big arm nut to move it into place. Getting old one out is just a case of removing circlip and starting engine.

D1Nut said:

And did that work ?

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Apparently the brake fluid swells the seal. It stopped leaking for over a year

ryan_1993 said:

Yeah its just a little bit of floppy movement just before hitting full lock but only when turning right weirdly its always been present that though

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I wonder if the box is centred properly... i haven't had to do it since my Series III, but RAVE will explain how...

tottot said:

I made a little two tube tool that presses the seal into place, it holds seal square and uses the big arm nut to move it into place. Getting old one out is just a case of removing circlip and starting engine.

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so the seal just blows out? I may have to do that to my P38... it has a bit of a weep...

Yes, rev engine and it should move out enough to get a hold of.

I am going to be the cynic now and suggest that a new seal is only a temporary fix. I replaced all the seals on my steering box out on the bench about 6 months ago. About 15k miles later I am now running a total loss steering system with a full reservoir lasting about 1000 miles, a far worse leak than it had before replacing the seal. I am in the process or research rebuilt units to swap a professionally rebuilt unit in. the advantage of this is most of them offer a 12month warranty that doe snot look to be mileage dependant, so if it starts leaking at any point in the 30k ish miles I do in a year they can have it back and I will get a new one.

A recon is probably best giver your yearly milage.
As noted above if a steering box is found to have side to side movement in the output shaft just replacing seal will not last, time for a refurb.