190D 2.2 Clutch Bleeding Woe's

[mbolton1990]

I've spent close to 20 hours trying to bleed the clutch system on my 190d and it still won't bleed out properly.. the car has been down for close to 3 months now in the process..

I've tried the following:
Reverse-bled with hand-bulb (got it to 50%)
Reverse-bled with hand oil pump canister (got it to 70%)
Reverse-bled with right front brake caliper (got it to 80% once)

I can't bench-bleed the clutch master cylinder as the nut is stripped that runs to the hard-line. And it literally destroys my back to try to even try to remove the master.. (slipped disc in back)
I don't have access to a power-bleeder, nor do I have the extra funds to buy one. I have tried literally just about everything..

What I fail to understand is I put a slave cylinder in this car 9 months ago, and it bled out within 5 minutes.. that was a cheap-o slave cylinder. This go-around I decided to try a Mahle/OEM-equivalent to see if it would last longer and this is what I get..

Really frustrating, this is probably the most ridiculous automotive job I have ever done.

Any tips/pointers?

[mbolton1990]

I've probably crawled underneath this car 200 times by now.. really at my wit's end.
I had it at 80% the other day, but 1/10 times pushing down the clutch it wouldn't work, and after 30 seconds the clutch would usually dis-engage. I drove it around prior like that for awhile but it's really unsafe in any backing situation..

The slave cylinder that was in it previously was indeed bad, it was leaking brake fluid around the seal. I bench tested the one that's in it now and it works fine. I've already taken it on/off 5+ times, trying to make sure the hard-line wasn't bent or at a extreme angle..

My rubber line that runs to my slave isn't in the best of shape (the outer rubber is deteriorating,but the inner line looks fine) No-one locally (within 2 hour radius) could rebuild it...

About to park the car up in the woods for a few years...

[Diseasel300]

I'd be looking at the clutch master cylinder on this one...

[mbolton1990]

That's where I'm at now also.
Issue is the nut that holds the hard line in is stripped. Is it possible to remove the master with the hard line connected?

No leaks whatsoever coming from the master. In typical MB fashion it seems, the nut has welded itself in there. Second time with a second car with the same issue.

Already sprayed it with PB and the nut is rounded.

Seems weird that both my master/slave would fail at the same time but I don't doubt it...

[moon161]

I was having bleed troubles with the clutch on my W123. Guy across the street had a bottle of lucas diff lube, it had a pump on it like a shampoo bottle, but with a fill tube on it. I forget how I joined them, but I fed it into the fill tube for the master/sender cylinder. I think I just put a hose on the slave/reciever bleeder into a cup and opened it, and pumped a 6 or 8 ounces of brake fluid through. That more or less took care of it.

[ah-kay]

I bled the clutch once after the clutch failed. I changed both master and slave at the same time. They are not that expensive and I don't know which one failed. I use the front brake nipple with a tube to bleed from underneath. It worked first time.

[mbolton1990]

Originally Posted by ah-kay

I bled the clutch once after the clutch failed. I changed both master and slave at the same time. They are not that expensive and I don't know which one failed. I use the front brake nipple with a tube to bleed from underneath. It worked first time.

Same, the first slave I put in this car I bled in 5 minutes with no issue using that method. It worked for ~6 months, the issue is I'm in school right now and money is tight. I'm looking at rebuilding the unit I have, I'm going to take it apart and check the bore in it. If it's too far gone, I'll replace the whole unit..

Originally Posted by moon161

I was having bleed troubles with the clutch on my W123. Guy across the street had a bottle of lucas diff lube, it had a pump on it like a shampoo bottle, but with a fill tube on it. I forget how I joined them, but I fed it into the fill tube for the master/sender cylinder. I think I just put a hose on the slave/reciever bleeder into a cup and opened it, and pumped a 6 or 8 ounces of brake fluid through. That more or less took care of it.

Cool! I tried a similar method, I pumped fluid down the hose that joins the Master Cylinder and the Fluid reservoir. That helped.. a little
Thanks for the response's guys. I'm gonna give it a break and put a new IP in my van,(oh the joys.. ) until I can come up with the money for a Master Cylinder. Seems like I never get any easy automotive work anymore lol..

[arcticathlon]

All i can point you towards is the method of how you are bleeding the clutch. I only have experience on a W123 with a Manual, but this is how it can quickly bleed the clutch. I just did it again today. Lets go back to basics to make sure you do it all right, cant hurt.

I bleed through the passenger front caliper.

1. get rubber hose to connect from slave nipple to caliper nipple.
2. Crack the slave nipple so that fluid can flow into the slave.
3. get a 2nd person; crack the caliper nipple and have them push the brake all the way in but DONT release the brake.
4. close the caliper nipple (with 9mm wrench or by hand) and then have them release the brake.
5. crack the caliper nipple and have them press the brake.
6. tighten the caliper and then release brake.
7. Check brake fluid reservoir to make sure you are not too low and refill if needed.
8. repeat this for about 25 times.
9. to check if the clutch is bled you must first close the nipple at the slave, or else you will pop off the rubber line and have to start over (don't ask how i know).
10. close all nipples and take it for a test drive. takes about 10 minutes to do.

Good luck.

[C.Doner]

My easiest method. After popping off hoses from bleeder screws and making messes I came up with an easy solution.
Place 3ft tight hose on the bleeder, fill master cyl container with fluid, keep it topped. make a loose knot loop around your exhaust or something to keep the hose up. place the end into a catch container . Pump your clutch pedal until all air is gone. See clear hose. The loose knot loop hose will keep air free brake fluid in the system after you close the bleeder with the pedal left in its up position. after tightening the bleeder you may need to rapidly pump the clutch to bring up pressure in the system. do this by hand as the pedal may not return from the floor at first. rest assured as long as things are in order this is a tried and true method. It works every time the first time. With this method, I will have an MB clutch bled in less time than it takes to jack up the car and place on stands.

[mbolton1990]

Thanks for the tips, much obliged!!

[Maxbumpo]

I've replaced clutch components on both a 123 and a 201, and in both cases I simply started the car in first gear and drove it around, let the vibrations drive the air up and out. Both times the hydraulics "self bled" just fine. I can't explain why this has worked for me so well.

Another approach: run a long clear line (fish tank air hose from Wal-Mart?) from the slave cylinder bleed nipple back up to the brake fluid reservoir, so you are pumping the fluid in a circle, and pump away at the clutch pedal until no more air is showing in the clear hose.

[Maxbumpo]

Another fellow once posted that he had great luck bleeding the clutch circuit with an old fashioned pump-type oil can, filled with brake fluid and back-bleeding via the slave cylinder. A hose made the connection between oil can and slave cylinder bleeder. Watch the reservoir level so you don't over-fill and spill brake fluid.