how to disassemble brakes of the front wheel of a 406D van from year 1975?

[miernik]

I have a van, Mercedes-Benz L406D from 1975, and I was venting the brakes after replacing the brake fluid, and the first two wheels went OK - these where both back and front right wheels. But the venting valve of the front left wheel was so rusted and not un-screwable that I broke the valve. And now I must somehow remove the half of the valve that is stuck in there. I thought I would unscrew the whole wheelbase, I mean the fixed part of the wheel, where brakes are, to make things easier, to be able to do it with an electric drill, which would not fit behind the wheel. So I took of the wheel, and then started unscrewing 4 nuts that I thought are holding the part.

Attached is a photo of the wheel base with 3 of the 4 nuts I tried to unscrew marked with green arrows. The 4-th nut is not visible on this photo because its hidden behind a piece of metal.

And now my problem: the 4 nuts, which are marked with green arrows, they unscrewed just a bit, so now they turn around quite easily with the 17 mm key, but they do not come off at all! They just rotate around, and the screws which are inside the nuts, they also turn around with the nuts, but nor the screw comes out, nor the nut comes off. And whats even worse: I can not even screw them back to the state when they where fixed, because turning them clockwise, also does nothing, besides turning - it doesn't fix them in place.

The red arrow points to the venting valve that I was trying to unscrew and I broke.

The blue arrow points to something that I have no idea what its for, and would be curious to know.

Any help with getting to disassemble this wheel are welcome. Even better where I can get/download/buy a service manual for this van, so I can read about such things explained? Maybe someone has a paper copy and can scan it and send me the scans?

 

[Number_Cruncher]

It sounds like you're working a bit outside your comfort zone - it might be best to get some professional help.

The blue bolt is the cotter pin that secures the king pin - leave it well alone!

You need to remove the drum, and the shoes within it, and then remove the broken wheel cylinder.

 

[miernik]

You need to remove the drum, and the shoes within it, and then remove the broken wheel cylinder.

But how to remove the drum? Are there any screws, nuts or anything to unscrew?

 

[Number_Cruncher]

I'm fairly sure the hub and the drum are integral - you'll need to take the wheel bearing out to remove the drum.

No more from me - sorry - I think you need to get some professional help.

 

[television]

You a looking at the wrong side and nothing comes off from there,, the bearing and hub need to be withdrawn complete

 

[miernik]

You a looking at the wrong side and nothing comes off from there,, the bearing and hub need to be withdrawn complete

Wrong side? You mean I should do something on the front side? But there are no screws on the front side or anything else to try! What should I do on the other side?

P.S. I don't get this "get professional help" thing, this is not rocket science, its just steel, screws and bolts, if I know what to unscrew I'll do it. Of course it will be faster to pay someone to do it and have it done - but that's not the point! Someone on the earth wide Internet has surely done such thing, so if someone knows, please just tell me which screw/bolt/whatever I need to unscrew/pull/whatever and I'll do it.

 

[Number_Cruncher]

>>I don't get this "get professional help" thing, this is not rocket science

No, it isn't rocket science. But, it's clear from how you're approaching the job and the questions you are asking that you don't have the experience to work on brakes of any kind - never mind the brakes of a commercial vehicle. The consequences of you getting it wrong - as you have been doing so far don't bear thinking about.

My strong advice to you is to obtain professional help - even if it's only someone who knows what they're doing looking over your shoulder every now and again.

 

[miernik]

My strong advice to you is to obtain professional help - even if it's only someone who knows what they're doing looking over your shoulder every now and again.

Someone looking over my shoulder will see the same thing as can be seen on a photo I can post here. If I ask someone offline, nobody besides me will be able to learn from it. That's why I ask here - because then someone else having the same problem later will be able to Google the answer. The Internet is such a great place for knowledge sharing!

You say I make stupid mistakes - but its from the mistakes that I can learn something.

Anyway - I have a service book of the 207D/307D/407D series, and if I had the same book for the older 406D I would be able to do it, can anyone tell me where I can buy such service manual for an 1975 406D? Or maybe tell me which other models have same/similar components so I can find such service manual easier?

 

[richyba]

Sorry but i dont know much about the 406 but nuts you have loosened on the back plate will go through to bolts behind the shoes which will be turning inside the drum so you need to take the drum off, I'am fairly sure it is integral with the hub and wheel bearing so tread carefully, I agree with other posts you might be as well to get a tame mechanic involved this kinda technology is second nature to the older fellas (thats why I'am sketchy being a young man), it might only need a push to send you in the right direction and you can do the donkey work, a drink often pays for help like that, hope this helps, not trying to put you off!

 

[miernik]

You a looking at the wrong side and nothing comes off from there,, the bearing and hub need to be withdrawn complete

But the opposite side looks like this photo attached below). The only thing that might be unscrewable there is the big thing right in the middle, which is a bit like a great nut, the size of the wrench would need to be metric 60 mm! The largest wrench I have seen is 32 mm. Do 60 mm wrenches exists? And is it the thing I need to unscrew to dismantle this drum to fix my problem, or do I do it some other way?

 

[television]

You undo that large nut, under the cover, and then you need to pull the drum off complete with the bearing, then you can see the brake shoes