240D manual 4 speed (non working) clutch question

[chetwesley]

I tried adding this on to the thread about my problems with the clutch on my 240D, but I got no response - no one probably wants to read through five or six pages of it to get to the simple question at the end.

To cut a long story short - some of you might (or might not) remember that a few months ago, I had the clutch suddenly cease working on my 240D. After taking the winter off from working on this project (and losing my job thus cutting my funding for it), I have now picked up fixing my 240D again (and found a new job) and ordered a slave cyl to install, hopefully this weekend.

I was thinking about this lack of clutch operation and was a little worried it was something mechanical inside the four speed because the trans was making a slight clanking/rattling when idling in neutral with the clutch pedal out since I have had the car (which someone here told me was probably the throwout bearing but not to worry about it too much because it could be like that for a long time before actually failing).

I wondered if anyone could quell my fears about that... one thing I recall is that I thought that when I was driving it without an operating clutch, that pressing on the clutch pedal seemed to pull back the clutch a little and allow the RPM to raise a little, but not enough to actually allow a proper shift.

Is that an indication that it is something hydraulic that went wrong, or could it still be something inside of the transmission? From what I know about the clutch system, it would seem to point to a hydraulic issue since it would seem that something is happening, but the hydraulic pressure is not enough to actually move the clutch disc back far enough to allow for switching gears, but I am pretty much a noob on the topic, so I could be wrong.

Thanks as always for any input.

[t walgamuth]

did you check rear compartment of mc?

[chetwesley]

Originally Posted by t walgamuth

did you check rear compartment of mc?

Rear compartment of MC? Is that the same spot where you look to check clutch disc wear? Or are you referring to something with the master cyl? Sorry, not sure what you mean.

[t walgamuth]

its easy to miss that the rear comp in master cyl is empty due to slow leak. first thing to lose is clutch . sorry, i'm hloding sleeping granddaughter and typing with one finger

[chetwesley]

Oh, you mean the reservoir for the fluid?

Yes, I should have posted a link to the original thread, but I filled up the reservoir and tried three different methods for bleeding (including the FSM method), and have the same situation.

I'm pretty sure it is not just air in the system at this point.

[Icefire]

Originally Posted by chetwesley

Oh, you mean the reservoir for the fluid?

Yes, I should have posted a link to the original thread, but I filled up the reservoir and tried three different methods for bleeding (including the FSM method), and have the same situation.

I'm pretty sure it is not just air in the system at this point.

I tried about three or 4 methods of bleeding my clutch system, the only method that worked for me, was the reverse bleed from the caliper, dont bother with other methods, Run a line from the brake caliper, to the slave cylinder on the trans, before connecting the line, open the brake caliper and push out the air using the brake pedal, then connect to the slave cylinder and bleed using the brake. Try this again if you have already tied this.

[IndianaJo]

Be sure to change the hose from the brake resevoir to the clutch master cylinder. I paid a mechanic to change my clutch master cylinder, and the idiot reused the 30 year old fill hose and it split and popped off on me 10 days later in the country 6 miles from a store. Fill up the clutch master cylinder by pumping into and out of a quart jar of brake fluid (peanut butter jar). Then bleed the hose by keeping the resevoir full of fluid and letting a little leak on the floor from the bottom. I had my carpet out. I did this out in the country, no special tools. I did a final bleed by cracking the slave cylinder fitting, forcing down the pedal, holding it down with a 16" 4x4 board against the seat, (no helpers) and closing the fitting. What made me so mad, I had to take the clutch master cylinder off again to get leverage to force the new hose on the cylinder- so the mechanic did nothing for me but strand me and get me a 12 mile walk. Used 5/16" emmissions hose, typically known as gas line hose, nothing special.

[charmalu]

Originally Posted by Icefire

I tried about three or 4 methods of bleeding my clutch system, the only method that worked for me, was the reverse bleed from the caliper, dont bother with other methods, Run a line from the brake caliper, to the slave cylinder on the trans, before connecting the line, open the brake caliper and push out the air using the brake pedal, then connect to the slave cylinder and bleed using the brake. Try this again if you have already tied this.

This is where Iam at the moment. Just installed a 4 spd in my 85 300D.

I flushed the brakes with my Motive Power Bleeder. and while I was at it did the clutch also, figured it couldn`t hurt. I did the brakes first, didn`t want dirty fluid going into the new clutch system.

I then reversed bled the clutch system from R/F brake caliper to slave. I used clear hose to see if it was pumping in fluid. The bleeder nipples were leaking fluid and making a leaky mess, think I might have had them cracked too much. might this also cause air to enter around the threads?

Can`t wait to get this thing on the road to see how it handles with a manual trans.

Charlie

[chetwesley]

Originally Posted by Icefire

I tried about three or 4 methods of bleeding my clutch system, the only method that worked for me, was the reverse bleed from the caliper, dont bother with other methods, Run a line from the brake caliper, to the slave cylinder on the trans, before connecting the line, open the brake caliper and push out the air using the brake pedal, then connect to the slave cylinder and bleed using the brake. Try this again if you have already tied this.

I have tried it two or three times now, this is the FSM described method. I am still having the same thing - no clutch.

The strange thing is that I don't seem to have any fluctuation in the level of fluid and I can't see anything moving up in the reservoir when I bleed the system. I don't know if I should, but I would expect that if fluid was circulating, that I would see something.

Originally Posted by IndianaJo

Be sure to change the hose from the brake resevoir to the clutch master cylinder. I paid a mechanic to change my clutch master cylinder, and the idiot reused the 30 year old fill hose and it split and popped off on me 10 days later in the country 6 miles from a store. Fill up the clutch master cylinder by pumping into and out of a quart jar of brake fluid (peanut butter jar). Then bleed the hose by keeping the resevoir full of fluid and letting a little leak on the floor from the bottom. I had my carpet out. I did this out in the country, no special tools. I did a final bleed by cracking the slave cylinder fitting, forcing down the pedal, holding it down with a 16" 4x4 board against the seat, (no helpers) and closing the fitting. What made me so mad, I had to take the clutch master cylinder off again to get leverage to force the new hose on the cylinder- so the mechanic did nothing for me but strand me and get me a 12 mile walk. Used 5/16" emmissions hose, typically known as gas line hose, nothing special.

I am going to try the slave cylinder first, as I didn't find any leaking around my master cylinder indicating any kind of problem with it, and it is cheaper and easier to do the slave (and seemingly a more common failure) - but I think there is also a flexible hose on the slave, which you are right, I should also make sure to change - so you just used 5/16" fuel line? It is probably the same size line on the slave.

[chetwesley]

Originally Posted by charmalu

This is where Iam at the moment. Just installed a 4 spd in my 85 300D.

I flushed the brakes with my Motive Power Bleeder. and while I was at it did the clutch also, figured it couldn`t hurt. I did the brakes first, didn`t want dirty fluid going into the new clutch system.

I then reversed bled the clutch system from R/F brake caliper to slave. I used clear hose to see if it was pumping in fluid. The bleeder nipples were leaking fluid and making a leaky mess, think I might have had them cracked too much. might this also cause air to enter around the threads?

Can`t wait to get this thing on the road to see how it handles with a manual trans.

Charlie

I actually had the same problem - particularly on the slave cyl (not so much on the caliper bleeder) - I couldn't get it to pass fluid through the slave bleeder valve without also leaking some around the threads.

I wonder if it could just be letting air in, and that is the only reason the clutch is still not working If you find an answer to this, make sure to post it back in here!

By the way, I really enjoy driving my 240D with the 4 speed. It is such a little tank, can't wait to get it back on the road. I am sure you will love it in the 300D!



At any rate, I would still be interested to know if anyone has any info about my original question regarding the symptoms I described and the possibility of mechanical failure. However, I see another clutch bleeding thread in the making

[charmalu]

Originally Posted by chetwesley

I actually had the same problem - particularly on the slave cyl (not so much on the caliper bleeder) - I couldn't get it to pass fluid through the slave bleeder valve without also leaking some around the threads.

I wonder if it could just be letting air in, and that is the only reason the clutch is still not working If you find an answer to this, make sure to post it back in here!

By the way, I really enjoy driving my 240D with the 4 speed. It is such a little tank, can't wait to get it back on the road. I am sure you will love it in the 300D!



At any rate, I would still be interested to know if anyone has any info about my original question regarding the symptoms I described and the possibility of mechanical failure. However, I see another clutch bleeding thread in the making

I`ll be sure to post the results on my success.
the 300D is a turbo and a 2:88 Diff. I have read mixed feelings on this set up. some love it and others condem it as being too high geared.

There is no flexable hose on the slave cyl. itself. there is a steel line connected to it, with a hose on the other side of the trans which is a part of the steel line. the hose is not replaceable by it`s self. I just purchased one from a dealer in porland, Or. $65.00 I think it was. Dealer here at home price was $58.80. thought it would be cheaper in Oregon W/O the sales tax. ours here just went to 9.25% bend over when you visit Calif .
The part# for that part is 123 295 1713
If you need the steel line from the master cyl that goes through the floor, it is $77.70 and Part# 109 320 77 53 64 .

Charlie

[Bajaman]

If you're thowout bearing is disintegrating, this could certainly affect the clutch operation. Not sure how you would check it without pulling the tranny though? It's really not that difficult to pull...

[lutzTD]

the correct hose from the reservior to the clutch master is $6 at MB dealer. not sure how the fuel line will react to brake fluid, but I wouldnt chance it myself.

[charmalu]

Originally Posted by lutzTD

the correct hose from the reservior to the clutch master is $6 at MB dealer. not sure how the fuel line will react to brake fluid, but I wouldnt chance it myself.

When I was hooking mine up, I went to our local NAPA store with my black braided piece of hose. I said do you have any of this? It`s the supply line from the Brake MC reservor to the clutch MC. they told me that black braided hose won`t hold up to brake fluid. told the guy (OWNER) that`s funny, every MB I see at PNP has this stuff.

He told the kid to get the blue braided hose, only stuff that will last with Brake fluid.
OK I don`t care about the color it is. Damn stuff was over $5 a foot, and only sold by the foot. bought 2 ft since it is more that a foot long. good thing too since I had to pull the MC down enough to get the hose on and left enogh still in the engine compartment to pull it back through. I used a zip tie on it, just because.

as INDIANJO was saying, the MC has to be removed to get this hose on, what a pita it is to R&R that. one of those times I wish I was a Midget.

think he used the fuel line because of where he was at the time. what a Dumb mechanic not to replace the hose when he was in there already.

Charlie

[Stevo]

[QUOTE=chetwesley;2164173]I actually had the same problem - particularly on the slave cyl (not so much on the caliper bleeder) - I couldn't get it to pass fluid through the slave bleeder valve without also leaking some around the threads.

It sounds like the slave bleed nipple is plugged, which is a common problem as that is the lowest part of the system. Pull the nipple and clear it. I have a good one on hand and simply swap it in.