Merc w123 master cylinder dilemma

2011dandd

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Hi
bit of a back story to this one so please bare with.

right, August last year clutch went on motorway. Had master and slave cylinder changed. Was to busy at the time to do it myself which I normally would have but had far to much work on.

drove out of the garage and the bite point was on the floor, thought that doesn’t seem right so went for a ten minute drive to see if things improved, it didn’t so drove back to the garage, the bloke said it will bleed itself right with use.

stupidly I left it at that. Since then I have gone for a couple of spins and always meant to have a look at it it but kids, work etc etc, don’t get a bloody minute to think.

any way had a look today and found a leak, fluid on the pipe from the master to the slave, found the leak to be coming from the elbow that connects the master cylinder to the hose from the fluid reservoir. The elbow is moving in and out no resistance at all not a tight fit in the slightest.

can anyone help with a part number for a replacement elbow and hose and how i go about fitting them properly. Can it be done with the master cylinder still in situ or will it be easier to remove?

cheers

hope someone can help

dan
 
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2011dandd

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The elbow is mine the one in situ is a generic photo but the same as mine.

mine pulled out so easily that I can only assume that it was never in properly
 

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2011dandd

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That’s fantastic cheers grober.

so that elbow (reservoir connection piece) should be a tight fit with a complete seal right? Should not pull out with the lightest of touches?
the connection was still in the hose and pulled away from the blinking master cylinder
 

grober

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the line from the reservoir to the master cylinder is not a high pressure line So I imagine its a tight push fit complete with o ring seal you might want to explore how to fix it more firmly in place with adhesive or a modiified jubilee type / pipe clip-assuming there is room- make sure its in the correct orientation/direction for the feed pipe from the reservoir. to do this properly means removing it probably.
 
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2011dandd

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Sorry i guess what I’m getting at is it’s a nice snug fit? Would resist the most gentle of tugs?

do you think the fax that this was letting by could be the cause for the bite point being on the floor? Or more likely the wrong length rod and no free play?
 

carat 3.6

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I'm going to guess the master cylinder that's been fitted is an aftermarket one and not a Mercedes part? The common problem with those is the seal around the elbow is too loose to hold the elbow in place, you cant glue it in there as you need to push the elbow into it after fitting the master cylinder.

As to your pedal biting close to the floor it will either be air that needs bleeding out, or the shim behind the slave cylinder is too thick.
 
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2011dandd

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I'm going to guess the master cylinder that's been fitted is an aftermarket one and not a Mercedes part? The common problem with those is the seal around the elbow is too loose to hold the elbow in place, you cant glue it in there as you need to push the elbow into it after fitting the master cylinder.

As to your pedal biting close to the floor it will either be air that needs bleeding out, or the shim behind the slave cylinder is too thick.
Thanks for this. I was under the impression tat only one size shim was available?
 
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2011dandd

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Got to repair and sort the bodged elbow first, but will do cheers.
Surely the garage would have used the existing shim, hope they did
 

vijilants

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Got to repair and sort the bodged elbow first, but will do cheers.
Surely the garage would have used the existing shim, hope they did

I'd say the garage who originally did the work is far from competant. To let the car out of the garage with the clutch bite point on the floor and also to state that it would "bleed itself out" is beyond belief, so if I were you I wouldn't put any faith in anything they have done.
 
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2011dandd

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I'd say the garage who originally did the work is far from competant. To let the car out of the garage with the clutch bite point on the floor and also to state that it would "bleed itself out" is beyond belief, so if I were you I wouldn't put any faith in anything they have done.
True
Had the work done back in August last year can’t believe I didn’t do mor back then. Do you reckon it’s too late to make a complaint?
 

Rollin

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Hi,
I changed master and slave on my W123 a few months ago. The elbow is a tight fit when inserted correctly and doesn't wobble around. It may be the case that it is not inserted all the way. I thought I had inserted the elbow fully, but it went further and became much more secure.
The problem you may have is that access to the elbow is difficult while the master is still on the car, let alone to apply enough force to seat it correctly. You risk breaking the elbow if you're struggling in a tight space.
 
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2011dandd

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Thanks rollin I thought this was the case. I have a new one on order and a beer piece of hose so hopefully fingers crossed this alone will relieve the issue
 

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