Tools to replace clutch slave cylinder on 1983 240d - PeachParts Mercedes-Benz Forum

karikomi1 · #1 05-18-2011, 05:47 PM

Anybody familiar with the spaces under a 123? I bought a replacement slave cylinder from oriellys but there is nothing in my sears hardware consumer socket set that will remotely fit over the bleeder valve, let alone the two bolts which secure the base of the cylinder. I need some guidance before I go to the big box hardware store and start buying specialty ratchets to fit this thing. In other words, i have a socket to fit the bolts but once affixed to the ratchet, the apparatus is too big to fit the small cavity where the bolts live. Additionally, the metric bleeder wrench that oreilly auto parts sells is too big to fit the bleeder valve on the slave cylinder. Thanks in advance. A summary of the problems that led to the bad-slave-cylinder diagnosis follows.

Clutch bled by vacuum pump method (bleeder valve desperately attacked with vice-grip needle nose pliers, yeah I was in a hurry) and reservoir full of dot4 good pessure initially (it goes into gear) then you go to shift (after driving away) and the pedal won't come back up. The latter step is always associated with a puddle of brake fluid on the groud under the car, which thankfully has so little torque that the brakes can stall it at idle. Checked the body under the drivers side floor mat for evidence of a failure in the master cylinder and it looks dry. The slave was covered in fluid when stubborn shifting prompted me to investigate the transmission system. that was before I attempted to bleed the clutch as described above.

charmalu · #2 05-18-2011, 08:56 PM

The slave is held on with 2 13mm bolts. I used my 1/4 in wratchet and maybe an extention to remove the bolts. If things haven`t been removed in quite a while, you might need a 3/8 wratchet and extention.

there isn`t a lot of room to work with your hands between the trans and tunnel. kind of a PITA tight area. not a lot of swing room.

the bleeder nipple is a 7mm. I use an open end, can`t get a flair nut wrench in the tight area.

The hard line in a 12mm, in case you need to remove it.

To bleed the clutch, you need to bleed from the bottom, and push the fluid up. the FSM explains it, to connect a hose from the R/F caliper nipple to the Slave Cylinder. them pump the brake peddle. It cycles the fluid from the brake cylinder reservor, through the caliper to the Slave,up through the clutch master and back to the reservor.

Here is a you tube video explaining the system

http://www.youtube.com/watch?v=wdf--suwqw0&playnext=1&list=PLE8DCFB0AB9C7498F

Charlie

karikomi1 · #3 05-19-2011, 08:25 PM

thanks, charmalu for the detailed response. ill be rounding up those items over the next week or so and hopefully get this show on the road soon!

karikomi1 · #4 06-18-2011, 12:46 PM

well i finally got a moment to do the repair and bought all the tools suggested in your excellent post, charmalu. the bugger of it is that replacing the slave requires removing it from the hydraulic hose that runs from the master and i pretty well stripped the hex fastener at the end of that hose leading out of the top of the old slave. im assuming there is no way to remove it now with a normal wrench. however i have googled every imaginable combination of "hose, slave, clutch, hydraulic, line, cylinder, mercedes", etc and no one seems to sell the item that i need to replace. the hose itself is a shaped metal hydraulic line that wraps around the top of the bell housing and terminates in a rubber section less than 1 foot in length at the distal end from the slave. bugger again on the ease with which this PITA accessible part is stripped. any ideas on where to find one (i live in columbus, OH which is far far away from the potomac salvage yard where most of the hulks seem to make their way these days)

leathermang · #5 06-18-2011, 02:05 PM

Pictures often really help on these kinds of questions...
I assume I have the same thing under my car... but it is close to 105 today ....
Is there a possibility a hydraulic shop can just make you a replacement hose with fittings ?

babyjames · #6 06-18-2011, 04:03 PM

a big bottle of valium! Bleeding these things is a pain.

Jay.

babyjames · #7 06-18-2011, 04:10 PM

If you can disconnect the hard line from the hose and remove the hard line together with the slave, you're more than 1/2 way there. Should be able to replace the rigid section from the hose to the slave with a pre-made brake line from Napa. If you have a bubble flare tool, you can shorten the line if necessary. Otherwise, well, improvise. Just remember, bending a loop into it might make it even more difficult to get all the air out.

Jay

charmalu · #8 06-19-2011, 02:40 AM

The hard line and the rubber hose are all one piece. the hose is crimped on. I bought this from the dealer when I did my 4-spd swap. was $72 about 1 1/2 yrs ago, comes as a straight piece that you have to bend and form to fit.

I bought it because I couldn`t salvage any from the junkers in the yards. most were coroded and rusted together.

a line could be made with the proper flairing tools. then have a hydraulic shop fab up a seperate hose. maybe a stainless hose might work?

Not much room in the tunnel to swing a 12mm wrench. I used a stubby 12mm to turn the hard line fitting, had to use it on an angle. Been looking for a thin 12mm crows foot wrench.

I rate bleeding the clutch right up there with the Evil Servo.

Charlir

babyjames · #9 06-19-2011, 12:40 PM

Big, fat, bummer. Blue Point bubble flair tool! Wish I had one, actually. Had to get a tech at a local indy to help me out. How long is the rubber section? Is it one piece all the way back to the clutch MC? Luckily I've never had to change the line. Did the mc and slave on the '83 last summer, I think, only to find that the driven plate was just rusted to the flywheel after sitting for a few months! Accidentally bumped the starter with the thing in gear and POP, it broke free. This after spending countless HOURS Replacing the hydraulic components and bleeding (NIGHTMARE!!) the bloody thing. Finally used my power bleeder, but even then it isn't straightforward. Do a search, you'll find plenty of info/opinions/different techniques to try! I think I got it pretty well dialed, now, so if you get totally stuck when you get to this point, p.m.

At Oil Filter Service, here in Portland, they sell generic stainless flexible brake lines in various lengths. Female fittings on both ends. If you want to make this a little more sustainable/repairable for the future - or if you're like me and are just too cheap to buy the part from the dealer - you could use one of those stainless flexible pieces, double flare (not bubble) the hose end of the hard line from the master, get the double flare connector for that end of the flexy bit, bubble flare connector for the other end and a generic metric brake hard line in close to the correct length to go from your flex hose to the slave. Now its modular, and no waiting for the parts to come in. Too bad they didn't do it in sections from the factory. See MB engineers aren't perfect!?!? Just another bit of evidence, actually, to add to my list.

Jay

charmalu · #10 06-20-2011, 01:57 AM

The length of the rubber hose from metal end to metal end is 9 1/2 in.

length of just the hose, is 6 1/2 in.

The hose is not a seperate piece. it is crimpted onto the hard line.

Charlie

SD300 · #11 06-20-2011, 02:53 AM

remember during the bleeding process, it takes a long process to build pressure up!
every time u bleed air out, the pedal feel a little bit of pressure, is almost 20 mins job to get the pressure fully functioning.
God bless

JB3 · #12 06-20-2011, 07:16 AM

The clutch line is made up of two pieces, the mb specific part # for the metal/rubber one is- 1232951713. this one travels from the master to the driver side of the transmission, the second hard line travels from one side of the tranny to the other.

The second piece can be made out of metric brake line available at most auto stores. In fact, the part is technically NLA from Mercedes, instead they will sell you a piece of SLS suspension line that must be shortened at 20 times the price of a piece of common brake line. The best way to replace this is to take the slave to the auto store, and see which metric line screws in, I am guessing 8mm or so.
If you don't have a bubble flare tool, you can have pretty much any garage flare the line for you once you decide on length.

You need a metric line wrench, rounding the fitting is the #1 most common thing to do without a line wrench, which grabs more sides to prevent this. The existing piece may be salvageable with a line wrench as well.

If you can get the short section of line off (hard to do as they are most often impossible to separate at the rubber section, you can cut off the existing flare, replace the fitting, and reflare it. It will be slightly shorter.

karikomi1 · #13 06-30-2011, 07:27 PM

well no luck on finding a replacement line. the female hex fastener on the rubber end is in good shape so i like the idea of recycling the part.

Quote:

Originally Posted by dropnosky

If you can get the short section of line off (hard to do as they are most often impossible to separate at the rubber section, you can cut off the existing flare, replace the fitting, and reflare it. It will be slightly shorter.

thanks for that advice. it sounds like you are saying that i need to cut the metal part above the fitting which is stripped on the slave-side and slide a threaded hex fastener over the end before using the flaring tool.

it seems like the problem is going to be finding a hex fitting that will fit the threaded female connection on the new slave. will napa carry something like that?

thanks

TnBob · #14 06-30-2011, 11:45 PM

Napa or any of the other chains should have what you need.

How about taking the original slave in and using it for a dummy ?