reamer Posted September 21, 2019 Author Share Posted September 21, 2019 Old Mercedes-Benz technician's trick, take the caliper closest to the clutch slave, find a piece of rubber vacuum line that fits snugly over the end of the bleeder screw and will reach to the clutch slave. Put it over the slave bleeder screw and the caliper bleeder screw. Loosen the slave bleeder about 1/2 - 3/4 turn. Have your helper depress the brake pedal, not super hard and open the caliper bleed screw till you here fluid flowing. When the pedal bottoms, close the bleeder and have her release the pedal, repeat a few times until the clutch MC reservoir is ready to overflow, that proves no air is left. Close the slave bleeder and try the clutch for feel. Mercedes-Benz clutch master cylinders sit on an angle and are impossible to bleed other than this or with a pressure bleeder from below. Thanks Bill I will try this today. do you know what the travel distance requirement is for a slave? reamer Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted September 21, 2019 Share Posted September 21, 2019 OK, So I have it all together, Got the T-case back today, got the shifters back and the carpet installed, All filled with ATF, Fire it up and it runs great! BUT …. Won't shift:nabble_smiley_angry:With engine off, not touching the clutch, I can shift into any gear. Engine on, clutch to the floor, can't get into any gear. Had my assistant push the clutch to the floor, the hydraulic slave moves in @ 5/8" … is this acceptable? or is there still air in the line? If I disconnect the line at the slave, it is solid as a rock, indicating no air in MC or line, I bled the Slave first by gravity feed and then the old fashioned way with assistant pushing clutch to the floor the opening the bleeder, then closing then having her release the pedal. No air is coming out, and we put a lot of fluid through the system, My question is with the slave movement of 5/8" is that enough or should it have to move more to disengage? Ron, I know the external slave spec is 5/8->3/4", but the arm (or fork) fulcrum is not centered. Not a 1:1 ratio. The concentric slave spec should be in Gary's Zf documentation. Link to comment Share on other sites More sharing options...
reamer Posted September 21, 2019 Author Share Posted September 21, 2019 Ron, I know the external slave spec is 5/8->3/4", but the arm (or fork) fulcrum is not centered. Not a 1:1 ratio. The concentric slave spec should be in Gary's Zf documentation. Will look now... Link to comment Share on other sites More sharing options...
Rogue_Wulff Posted September 21, 2019 Share Posted September 21, 2019 Will look now... I have to wonder, did the bore/stroke of the master change between the older and newer models? That could be an issue with a newer slave/older master combo... Link to comment Share on other sites More sharing options...
Steve83 Posted September 21, 2019 Share Posted September 21, 2019 ...did the bore/stroke of the master change between the older and newer models?Yes, as these diagrams indicate: https://supermotors.net/getfile/1082060/thumbnail/clutchmastercyl.jpg https://supermotors.net/getfile/1082059/thumbnail/clutchmastercxl.jpg Link to comment Share on other sites More sharing options...
reamer Posted September 21, 2019 Author Share Posted September 21, 2019 ...did the bore/stroke of the master change between the older and newer models?Yes, as these diagrams indicate: https://supermotors.net/getfile/1082060/thumbnail/clutchmastercyl.jpg https://supermotors.net/getfile/1082059/thumbnail/clutchmastercxl.jpg OK I'm screwed.. Bill I did the reverse bleed using the front brake cylinder, the clutch slave is completely bled. But still not enough throw. So, yep probably the MC does not have the volume for that slave, or the slave does not throw far enough? But I know NAPA 819 5931 line and NAPA 73002B slave does work with my configuration, Soooo, it's back to pulling the tranny again to install a configuration that we know does work. But it won't be me this time. What takes me 10 hrs on my back with a creeper, the tranny shop can probably do in 4 hrs with a lift and tranny jack. Thank you all for the help Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted September 21, 2019 Share Posted September 21, 2019 OK I'm screwed.. Bill I did the reverse bleed using the front brake cylinder, the clutch slave is completely bled. But still not enough throw. So, yep probably the MC does not have the volume for that slave, or the slave does not throw far enough? But I know NAPA 819 5931 line and NAPA 73002B slave does work with my configuration, Soooo, it's back to pulling the tranny again to install a configuration that we know does work. But it won't be me this time. What takes me 10 hrs on my back with a creeper, the tranny shop can probably do in 4 hrs with a lift and tranny jack. Thank you all for the help Seems to me it would be cheaper and easier to drill your firewall for the diagonal mount master cylinder. IDK what a transmission shop gets for four hours R&R plus bleeding that damned slave, but a new master and an hour of your time can't be close. How did you end up with the wrong slave to begin with? Link to comment Share on other sites More sharing options...
Rogue_Wulff Posted September 21, 2019 Share Posted September 21, 2019 Seems to me it would be cheaper and easier to drill your firewall for the diagonal mount master cylinder. IDK what a transmission shop gets for four hours R&R plus bleeding that damned slave, but a new master and an hour of your time can't be close. How did you end up with the wrong slave to begin with? If I am reading that correctly, the older master has a HIGHER displacement than the later version. Seems this would have the opposite result, in that the older master would cause the newer slave to have too much travel, not too little.... Link to comment Share on other sites More sharing options...
reamer Posted September 21, 2019 Author Share Posted September 21, 2019 Seems to me it would be cheaper and easier to drill your firewall for the diagonal mount master cylinder. IDK what a transmission shop gets for four hours R&R plus bleeding that damned slave, but a new master and an hour of your time can't be close. How did you end up with the wrong slave to begin with? Well the quality parts people and their books state "Compatible" The original slave was a thin aluminum disk base, the "new" one is a thick plastic base, red flags were raised but "compatible" is the word, Then I had to get new bolts to mount it, (thin aluminum disk = short bolts, thicker disk needed new bolts. That's were it went down hill fast, (after hours of work to install the ZF) this is where I found the "old" clutch line will not mate to the new slave. Then we had to find a new line that would mate to the new slave, but was not bent correctly, (90 degrees off at the master). Then we found a line with a 90 elbow but leaned against the exhaust manifold. Now after two days of bleeding and re-bleeding, it looks like there is not enough throw to disengage the clutch. I'm really surprised I have not damaged the paint with all this brake fluid flying around. Now checking with them they say the master is "compatible" with either slave, So if I go with a NEW Master with the port facing down, I would have to get the new-style line with the line pointing up again so they will connect at the new master but may not mate (but should) to the slave....and you mentioned the possibility of reconfiguring the NSS. I know the old style slave and old style line and old style Master works in this truck. So starting over, I will bite the bullet and get everything again. Have all the old style re-installed along with new pressure plate and clutch. Now my wallet, back and arms say have the tranny shop do it, but my conscience, says "double down and do it moron" Also not sure what constitutes a worn clutch (by thickness) so Crack it open and get it all while in there.... Link to comment Share on other sites More sharing options...
85lebaront2 Posted September 22, 2019 Share Posted September 22, 2019 Well the quality parts people and their books state "Compatible" The original slave was a thin aluminum disk base, the "new" one is a thick plastic base, red flags were raised but "compatible" is the word, Then I had to get new bolts to mount it, (thin aluminum disk = short bolts, thicker disk needed new bolts. That's were it went down hill fast, (after hours of work to install the ZF) this is where I found the "old" clutch line will not mate to the new slave. Then we had to find a new line that would mate to the new slave, but was not bent correctly, (90 degrees off at the master). Then we found a line with a 90 elbow but leaned against the exhaust manifold. Now after two days of bleeding and re-bleeding, it looks like there is not enough throw to disengage the clutch. I'm really surprised I have not damaged the paint with all this brake fluid flying around. Now checking with them they say the master is "compatible" with either slave, So if I go with a NEW Master with the port facing down, I would have to get the new-style line with the line pointing up again so they will connect at the new master but may not mate (but should) to the slave....and you mentioned the possibility of reconfiguring the NSS. I know the old style slave and old style line and old style Master works in this truck. So starting over, I will bite the bullet and get everything again. Have all the old style re-installed along with new pressure plate and clutch. Now my wallet, back and arms say have the tranny shop do it, but my conscience, says "double down and do it moron" Also not sure what constitutes a worn clutch (by thickness) so Crack it open and get it all while in there.... Yes, and years ago Goerlich exhaust said the 1 7/8" tailpipe was "compatible" with my 1971 Colony Park 429 engines's exhaust. Funny the original was 2 1/4". Oh, you have to use a reducer to fit it to the muffler. Tell me how a pipe with an ID of 1 3/4" will flow as much as one with an ID of 2 1/8"? That is a cross sectional area of 5.5 square inches vs 6.68 square inches or only 82% of the area. Yes, it is compatible, it will physically fit, flow enough at WOT, not! It was shortly after that I had a pair of dual exhausts installed. Link to comment Share on other sites More sharing options...
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