Do always replace the slave cylinder when replacing your clutch?
 

I read an article on the internet talking about replacing a clutch that stated: "I would also recommend replacing the clutch slave cylinder as well. Quite often an old slave cylinder will not be able to handle the new parts and will blow out in two or three weeks."

Is this the case on a Mercedes? I'll be replacing my clutch soon and am now wondering whether I should replace the slave cylinder as well.

Scott

Yep.

If you think about it, the newest manual W123 out there is 22 years old. If it has the original slave cylinder, it's probably not going to last much longer.

That is always a wise idea with a manual transmission. The slave is usually very cheap.

my experience of one
 

Well, my experience of one confirms this belief. While I was under the car (240D) preparing to bleed the clutch master cylinder I wondered about this. I wished then that I had ordered the slave at the same time. I'm going to be back there again soon. What would you do if the slave cylinder has already been replaced (130,000) and the master needs replacement at 142,000? This is the situation I'm facing with my 190D. I hate to replace parts unless necessary (read cheap). Am I tempting fate once again?

Kevin
1979 240D manual
1984 190D manual

81 240d slave cylinder
 

Over a year ago I purchased an 81 240d manual. I bought it from a repair shop who had reciepts of alot of stuff done on it including a new clutch. Not more than three weeks later I pushed in the clutch while driving to find it not there and fell to the floor so to speak. Later I found out that everytime i pushed in the clutch...it would spit a little bit of brake fluid from the slave cylinder. It was easy to replace and it only cost me 30 or 40 bucks at Inter Auto Parts in San Diego. I would think that if you plan on replacing the clutch than I would also plan on replacing the slave cylinder. Unscrew a couple bolts like 12mm and the oil line, to attach do the reverse. With mine I just got in the cab and pumped the clutch about a 100 times and I had a new slave cylinder. I have heard of some guys that do it differently but it worked for me.
-Stephen

I would do it just for the better clutch feel alone.

No. If it is working and not leaking why open up the hydraulic system for no reason? You can remove the slave cyl from the transmission to prevent any difficulties in bleeding the system when you reassemble. It's not like you have to pull the tranny if you need to replace it later.

Least you can do is check the cylinder for scoring, and if not scored, change the kit which is cheap. Most important is to change the throwout bearing in the clutch.

What should I do about the flywheel? Do you think I can just install the new clutch and not worry about it?


Scott

Yes

i would say yes... my stupid ranger has the slave inside the bellhousing and they really really suck and die at about 40k so you have to pull the tranny to fix it

Ditto....
 

I was gonna say basically the same thing, except that it's my F-150.....Ford slave is bositioned around the transmission input shaft....thus tranny has to come out.....if I remember correctly the new Ford slave cylinder was less than 50 bucks....my labor is free, but to pull tranny is a real pain and worth the cost of a slave cylinder.....

I do not have a clue as to how a MB slave cylinder is arrainged......if you don't have to pull the transmission (or disassemble half of the car) to replace the slave cylinder.....then go for cheap.....:D

Bottom line, what do you figure your own labor is worth to you??

SB

I don't think you have to pull the tranny to replace the slave cylinder on the MB. However, I went ahead and just ordered one from Phil. I only want to have to mess with this once so I might as well do it while I'm in there. The only other thing I'm worried about is the flywheel but it looks like I can probably just install the new clutch and not worry about it.

Scott

The slave is an easy replacement but the master is a bugger, which is why I dont change that, till it need too be. come too think about it, I don't change the slave till it needs to be either, because its easy and why break into the hydraulic system till you need to? I would have to say, "if it aint broke, dont fix" it:)

ditto
 

I agree with Stevo. Why waste a good slave cylinder. I wont break hydraulic lines unless its needed. Mine has been good on a different clutch for a while.

If you're doing it yourself, don't worry about it until it breaks. You can always replace the slave later.

If you're paying someone to do your clutch, it will me MUCH less expensive to have him replace it now, with the tranny out, than it will to have him replace it later down the line...

Just make sure you mark its orientation and torque appropriately.

I vote not to replace unless you know its history. No reason to open a perfectly working hydraulic system. Replacing the slave is no more of a pain than doing brake pads........

On many newer vehicles, the slave is inside the tranny.in this case, it is worth it to replace it.

if it is outside on a 240, then you can replace it anytime.

i say it depends. if you know the history of the car it becomes an easire call.
if the car has 300k on it an it has never been changed, then yes i would change the slave master and new fluid. the bleeding and the clutch master are the only tough parts. the slave is easy except for the bleeding part.

and i would not put in a new clutch without turning the fw. i did this once on my bmw bavaria, and found the the new clutch assembly would not fully disengage because the face of the fw was too far forward from the mounting point of the pp and disc. this made the leverage change on the pp and consequent failure to disengage the clutch fully.

doing the job right means extra steps sometimes. there might be a way to measure and determine if it is necessary but i doubt that i would trust it.

a mistake means dropping the exhaust driveshaft and tranny.

again

good luck

tom w

You might have had the "odd" one that was way out, because I have put at least four 240Ds togather without having the f/w done and no problems. I am wondering if most folks do the F/W.

i think that benz flywheels are probably tougher than the old beemer was but do you want a clutch that will last another 275k or one that will only last 150k?

it is not much trouble. the machine work is what, $30?. i reckon the biggest cost is the (maybe) new flywheel bolts.

tom w

190D 1984 2.2 5spd slave cylinder ,can someone tell me where this is located.

Please do not resurrect dead threads. Start a new thread after searching the archive to make sure someone hasn't already answered the question.

To answer your question, The slave is mounted on the side of the transmission bell housing.

My clutch master cylinder was leaking at 122k miles so I replaced it.
However, being a noob at the time I did not properly bleed the system and thus had "spotty" clutch action, so in my ignorance and thinking that if the master was leaking, the slave must not be far behind, I replaced it.
The original slave showed no signs of leaking and, again, I did not fully bleed the system so my clutch just got worse and worse.
Moral of the story is , don't break into the hydraulic system unless absolutely necessary.The parts replacement is easy, the bleed can be a PITA.

Bleeding gets easier each time;)

Got my parts ,found the sick slave cylinder and its leaking like a sieve,the master also had a slow leak .The biggest hurtle is still the bolts on the slave C ,the bottom nut was no problem ,the upper 13mm is a PITA.Ill need to make a 13 wrench with a 30degree angle just to get at it.Had to use a crows 12mm wrench to pull the hydro line but its free and out of the way.Sunday Ill be starting back at it, now Ill be under it with all my special tools for the fix ,Gees.The 190s are not nearly as easy as the 240s and I agree with T.W.THAT ITS BEST to replace both after alot of age .Battles are always won on the ground not throwing your wrenches in the air.

Not quite true:). With a new clutch plate the slave piston is stroking in the front half of the cylinder,the full length of the cylinder being immersed in fluid. By the time the plate is worn out the piston is stroking in the rear half of the cylinder leaving the front half dry and exposed to air for perhaps several years. I was unlucky on both occasions I fitted a new plate and had a leaking slave within a few weeks. The front of the cylinder turned out to be heavily rusted and pitted chewing up the seal when the piston returned once more to the front.

But I agree with you - no point in replacing it until it does start to leak!;)

I made that mistake. My master and slave were about the same age, and my master failed. I was feeling cheap and only replaced the master. 2 months down the road I was covered in brake fluid again changing the slave. Both have rubber, were equal age, and rubber deteriorates over time, right? So I figure in the future, I'd recommend replacing both at the same time.

Well I wouldn't go as far as calling that "insanity" suffice to call it futility. If you are looking for a short cut to a leaking cylinder just hone the bore out oversize:rolleyes:

On that upper slave bolt, try dropping the tranny cross member (four 13mm bolts on a 123) to get a little more room. Maybe use a wedge to hold it down.

What's wrong with resurrecting old threads?

Its fun reading through them.;)

Old threads have alot of wealth of info ,the quote of dont use them ,like this one, "Please do not resurrect dead threads. Start a new thread after searching the archive to make sure someone hasn't already answered the question."
I Revived this one because it matched my original question and had alot of good input.Enough said.
I final got the 190s slave cylinder bolt away.It required me to setup a 1/4 inch ratchet with 2 swivels and two 4 inch extentions to get the little sucker.The other problem is when reassembling the entire brake and clutch piece ,youll be looking at reattaching the brake fluid resorvoir hose piece to the master clutch cylinder first before bolting up the unit ,this is your main fluid feed and you dont want to kink it or mess this up.I bought a newer longer piece due to old age and not much room given when reinstallment on the original shorter original hose.It sleeves the line into the opening allowed ontop of the masters C.Bleeding the clutch is the job on hand and Im sure in costs a shop would have dropped me for north of $400. on the fix .In parts and new tools Im in it for less than $145.Looking back on this youll have 3 hurtles ,the upper bolt on the slave cylinder ,the reinstallment of the master cylinder to the pedal assembly due to those peskey small clip holders that holds the master C rod in place,and the finally the main hydro line feed to the master cylinder.I dont know how many 5spd 190s are out there but if this task is on your plate I hope this helps a DIY er er out there.

You didn't try lowering the tranny by dropping the cross member?

I had limited tools due to my storage unit being broken into ,jacked the car up high enough but didnt feel safe loosening up anything will underneath the car .Thanks ,Ill try this next time.

I may not live long enough to ever have to do another 617 clutch slave again:D but if I do I'll try it. I dont think it will drop very far and a wedge may be needed to hole it down, but even an inch lower would probably make a big difference.

Steve - An "S" shape 12/13mm ring spanner makes that top bolt a breeze.:cool: After fitting a new clutch a few weeks ago I doubt if I will be needing it again either:(

Thanks, also really appreciate your fine post about clutch bleeding. I finely get it figured out and you come up with the "better mouse trap' :D I"LL also try that "oil can" method if I live long enough to need to do it again.

A "ring spanner" would be a regular old "box end" wrench? and then start bending till it reaches up there and has room to turn the nut, Yes. Thanks again

No, it is a double ended ring spanner in the form of a letter S about 8" long. any auto spares store should have them - usually in sets. Very useful for all sorts of other tight spaces too:cool:.

http://www.alibaba.com/product-gs/283493586/S_TYPE_DOUBLE_RING_SPANNER/showimage.html

[QUOTE=Beagle;2495728]No, it is a double ended ring spanner in the form of a letter S about 8" long. any auto spares store should have them - usually in sets. Very useful for all sorts of other tight spaces too:cool:.

Oh OK, I was under the impression you bent one up, outstanding, another tool to buy:D Thats easy... This five cylinder engine, or I should say, the extra space this five cylinder engine takes up, requires a few more tools and sweat than my 616s do;)

Recycled
 

for customer