Theory on why clutch bleed can be difficult - Page 2 - PeachParts Mercedes-Benz Forum

Stevo · #16 05-20-2012, 12:11 PM

Quote:

Originally Posted by sokoloff

Correct, the pressure bleeder is on the reservoir just like it is for the brakes. I have seen/felt no downside to my doing it this way. Clutch still feels fine afterwards and the clutch bleeder screw always produces the dirtiest fluid of them all. I don't think I would want to push that dirty fluid back up into the reservoir? Does not the pressure force out any air if there was some just as with the brakes?

Flushing the clutch system along with the brakes is a good idea and probably hardly ever gets done. I found my clutch slave bleed nipple completely plugged when I did my 79 a few years ago. This procedure is not to be confused with clutch "bleeding". If you have air in the system flushing wont get rid of it.

charmalu · #17 05-20-2012, 12:33 PM

Quote:

Originally Posted by Stevo

Maybe is does work from the top down where you are, I've heard hurricanes rotate in the "other" direction as does water going down the drain plus you folks are upside down as proven by looking at a map of the earth. Therefor "from the bottom up" to us would be from the top down to you.

There, problem solved, we are both right.

I almost spilt my coffee reading this.

Charlie

gastropodus · #18 05-20-2012, 04:53 PM

Well, I've progressed a little... it turns out that it takes quite a bit of pressure to push fluid up into the system. There is only a tiny orifice in the bleeder, and you also have to pressurize against the weight of the column of fluid that you're pushing uphill. The upshot is that my peanut butter jar reservoir just simply wasn't up to the task, and air was leaking around the rim.

So, I invested the time to find a suitable oil can (originally, I couldn't find one with a small enough tip to fit over the same tubing that goes over the bleed nipple). Now, with the oil can I can see that fluid is able to enter the system. I'm taking a break right now from pumping; the squeezing gets hard!

By the way, I also taped the bleeder screw with Teflon tape, as I saw suggested on an earlier thread.

Kurt

Stevo · #19 05-20-2012, 04:55 PM

[QUOTE=

Since then I removed the transmission etc..... and am back to the bleeding problem. that was 19 months ago and the car has sat since then. but since the 240 drives..................... do need to flush the 240, so need to get at least one working back up car.

Charlie[/QUOTE]

I cant believe your having so much trouble. Something must be amiss somewhere. Did you check to see your slave nipple was clear? When you push fluid up directly from the slave up through to the master then to the reservoir what can go wrong? You might over flow the reservoir if your not careful but I cant see where there can be a problem. Theres no pumping the brake pedal or different sizes hoses to deal with. If your system is in order the oil can method is simple and should be fool proof.

Stevo · #20 05-20-2012, 05:03 PM

Quote:

Originally Posted by gastropodus

Well, I've progressed a little... it turns out that it takes quite a bit of pressure to push fluid up into the system. There is only a tiny orifice in the bleeder, and you also have to pressurize against the weight of the column of fluid that you're pushing uphill. The upshot is that my peanut butter jar reservoir just simply wasn't up to the task, and air was leaking around the rim.

So, I invested the time to find a suitable oil can (originally, I couldn't find one with a small enough tip to fit over the same tubing that goes over the bleed nipple). Now, with the oil can I can see that fluid is able to enter the system. I'm taking a break right now from pumping; the squeezing gets hard!

By the way, I also taped the bleeder screw with Teflon tape, as I saw suggested on an earlier thread.

Kurt

Oh yah, Finding a suitable oil squirt can does present a problem. The HF one I tried first was a joke.

charmalu · #21 05-20-2012, 06:50 PM

Quote:

Originally Posted by Stevo

I cant believe your having so much trouble. Something must be amiss somewhere. Did you check to see your slave nipple was clear? When you push fluid up directly from the slave up through to the master then to the reservoir what can go wrong? You might over flow the reservoir if your not careful but I cant see where there can be a problem. Theres no pumping the brake pedal or different sizes hoses to deal with. If your system is in order the oil can method is simple and should be fool proof.

The system was working just fine, only had 22K miles on it, and decided to swap in a different transmission. get it it all bled and working. after driving it for a while realise there is a bearing in 3rd gear (or seem like it is) so decide to swap in the first one. then the shaft wouldn`t line up with the clutch, I pushed and beat one the damn thing. had it out to see what was wrong, back in and more beating and pushing etc...was getting late so closed up shop for the night.

Next morning decide to remove PP and clutch. remove it and pilot bearing fell out. so guess it dropped out when I removed the trans. then put clutch back in and hear the Disk rattling.

had 2 broken springs, the 2 large one`s of the 6. order a new one and button things back up.

Now this time around, the clutch just won`t bleed. the slave and MC were new 22K miles befor and also bled ok about 2 monthts before when swappin in the second trans..

I just got to the point, I`ll get to it later, and threw a tarp over the car.

I now have the 617 FW to install, so back to pulling the trans etc...

Since summer is back and either get it going or plant flowers in it for a yard ornament.

.

I bought one of those HF pump oil cans, maybe that`s my problem, need to blame it on something.

Charlie

gastropodus · #22 05-20-2012, 10:49 PM

Well, I think I finally got it bled, with the oil can method. It seemed to take about six ounces to fill and bleed a totally dry system, if anyone is interested.

I'll pass along another tip: I marked the eccentric nut at the top of master cylinder piston so that when it was shortest the side facing the viewer in the footwell showed a zero. Then the two faces on either side of that nut face were marked 1, etc. That way I could tell easily when the piston was at its shortest adjustment point.

Kurt

Kurt

gastropodus · #23 05-20-2012, 10:50 PM

And Charlie: when I'm down in July I would help you with your bleeding or install!

Kurt

Metafly · #24 05-21-2012, 12:57 AM

The best way I have found to bleed up through the slave is to use the brake pedal by connecting a tight fiitting hose from the closest front brake bleeder to the clutch slave.

layback40 · #25 05-21-2012, 07:38 AM

Quote:

Originally Posted by Stevo

Maybe is does work from the top down where you are, I've heard hurricanes rotate in the "other" direction as does water going down the drain plus you folks are upside down as proven by looking at a map of the earth. Therefor "from the bottom up" to us would be from the top down to you.

There, problem solved, we are both right.

Stevo,
I thought you believed the world was flat !!!

Just remember that we are so far in front here that we have done the days work before you guys even get to waking up!

I have never had to bleed a clutch bottom up. not even when I lived on your side of the pond.
Always put the slave & MC back in pre-filled with fluid. If you press the slave back right in, the volume of fluid in it displaced is often more than the volume needed in the line.
An old dodge truck a friend had needed the MC internals to be filled with a syringe as the hole from the reservoir was so small.
Good luck with your bleeding!!!

Stevo · #26 05-21-2012, 09:02 PM

Quote:

Originally Posted by layback40

Stevo,
I thought you believed the world was flat !!!

Just remember that we are so far in front here that we have done the days work before you guys even get to waking up!

I have never had to bleed a clutch bottom up. not even when I lived on your side of the pond.
Always put the slave & MC back in pre-filled with fluid. If you press the slave back right in, the volume of fluid in it displaced is often more than the volume needed in the line.
An old dodge truck a friend had needed the MC internals to be filled with a syringe as the hole from the reservoir was so small.
Good luck with your bleeding!!!

I know the worlds not flat because I've been out there and haven't fallen off the edge, However its still a mystery why people below 40 or 50N dont fall off .

Yes, pre filling the slave and MS is the way to go but you should still be able to bleed the system should your brake fluid get low and she takes a gulp of air.

charmalu · #27 05-22-2012, 09:52 AM

Quote:

Originally Posted by gastropodus

And Charlie: when I'm down in July I would help you with your bleeding or install!

Kurt

Kurt, be looking for you.

the 240 should make the trip now.

Charlie

Rocket99 · #28 07-25-2019, 09:48 AM

I read it on this forum I think
Beat my brains out until i did this, then, instant success.

run clear plastic tube from RF wheel bleed nipple to clutch slave bleed nipple. Make sure that tube is full of fluid. Speed bleeder on RF bleed nipple is good too.

you must use a small hose clamp on both ends. Those clamps are manditory.

open both nipples, slowly depress the brake pedal several times. You will hear the fluid bubbles rising thru the system pushing fluid back to the reservoir. Clearly bubbles are not driven to the bottom of the circuit easily, but do rise back to the reservoir.

Instant success

okyoureabeast · #29 07-25-2019, 12:29 PM

Honestly, I think the OP didn't bench bleed his MC (unless I missed it).

Also, curious necropost. What lead you to revive this thread? I always wonder when I see an old thread reappear.

party · #30 07-26-2019, 05:30 AM

Lots of old threads pop up when you search the entire WWW for "W123 clutch master slave bleed" not using the board's search function. I assume people reply without regard to or even taking not of the date(s) of the previous posts.