mas8230 Posted May 30, 2004 Share Posted May 30, 2004 I Have bled and bled and bled for over an hour, and I still can hardly get any push rod travel on my slave sylinder, maybe 3/8" at the most! I have a Howe 7/8" master cylinder, and did the "re-working" of the slave exactly as JTR. Even better, I have an aluminum slave. But I cannot get any movement at the fork. This is the only thing keeping me off the road. EVERY part is brand new. Any ideas, suggestions, etc.? Quote Link to comment Share on other sites More sharing options...
Tim240z Posted May 30, 2004 Share Posted May 30, 2004 It's gotta be at the master. Either the master hasn't been bled enough (I assume you bench bled it), or the pushrod from the pedal to the master isn't sdjusted correctly (try making it longer) Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 30, 2004 Share Posted May 30, 2004 Could be that the clutch rod is already too long (happened to me once). That would keep the port from the reservoir into the master from ever opening. Should have about 1/8" free play in the pin before it engages the master at all. Quote Link to comment Share on other sites More sharing options...
mas8230 Posted May 31, 2004 Author Share Posted May 31, 2004 OK, I spent all day trying to make it work, And re-bleeding after each adjustment. - First, I tried shortening the rod from pedal to master, no significant improvement. - Then, I made it longer, it helped significantly. It still wouldn't push the fork in all the way, maybe 1/2 at best. However, If I pumped the clutch 3 or four times, it would go into gear when running. - So I figured maybe go a little longer and I'll be there. I went just about as far as I could on length. Now, I cannot get any movement out of the slave at all!! - I kept bleeding and get nothing but fluid, now about 2 quarts later. - I took the slave and master off for now. The slave seems like it is backwards. When I push in the clutch, shouldn't the piston be pushing the pushrod into the fork? The piston in mine (if mounted) is extended all the way TO the fork. - There are absolutely no leaks in the system. However, I do hear alot of "swishing" when my partner pumps the clutch. - I did notice that I have "a ton" of play in the fork before coming in contact with the pressure plate fingers. How much is normal? Where do I go from here? - It almost seems as if the pushrod on the slave is too short, could it be? What is proper length? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 31, 2004 Share Posted May 31, 2004 - I took the slave and master off for now. The slave seems like it is backwards. When I push in the clutch, shouldn't the piston be pushing the pushrod into the fork? The piston in mine (if mounted) is extended all the way TO the fork. Am I reading this right? The piston is all the way back in the clutch master, you have play between the rod and the master, and on the slave the piston is ALL THE WAY extended? If so, I'd say you have the wrong pin for the slave or the wrong slave. The pin needs to be long enough so that the slave is able to get some throw. If the pin is too short than the slave cylinder won't have enough throw to push the fork. BUT- if you read it another way, it sounds like the difference between a manual adjusting slave and an auto adjuster. The manually adjusting slave has a long threaded pin and a return spring on the slave. You set the gap between the pedal movement and when the throwout bearing touches the pp. In the auto adjusting slave, it's more like a caliper piston (as I understand it). You push on the clutch, and it pushes the pin into the fork. When you let off the clutch, the fork pushes the pin back, and it might get a little more pull back from the seals in the cylinder itself, but the pin is always extended so that it touches the fork. There are absolutely no leaks in the system. However, I do hear alot of "swishing" when my partner pumps the clutch. One thing I've seen people do on both brake and clutch master cylinder bleeds is jam the pedal down really hard. This causes thousands of little tiny bubbles to get injected into the reservoir, and the more you bench bleed like this, the finer the bubbles that go into the system. If you started your bleeding adventure this way, I'd say you just let it alone for a day or two. The clutch system should be "open" so that without the clutch being depressed the port to the reservoir is open. So if you leave it alone eventually most of the air bubbles in the system will float to the top and into the reservoir, and the system should basically bleed itself to some extent. Quote Link to comment Share on other sites More sharing options...
mas8230 Posted May 31, 2004 Author Share Posted May 31, 2004 What about the excess slop in the fork? What is normal? Quote Link to comment Share on other sites More sharing options...
mas8230 Posted June 1, 2004 Author Share Posted June 1, 2004 OK, I put everything together and started from scratch, a nice bleed and all. Absolutely no air in the line!! I put the slave in without the boot so I can see slave piston travel. MOUNTED, the piston sits about 3/4" into the slave. CLUTH ALL THE WAY TO THE FLOOR, the piston comes all the way to the snap ring, and the fork moves about 1/2", 5/8" at the most. I'm thinking that maybe a longer pushrod from slave to fork may be the trick. Any suggestons? Quote Link to comment Share on other sites More sharing options...
fastzcars Posted June 1, 2004 Share Posted June 1, 2004 Maybe the throwout bearing is too far away from the clutch finger's. I have a McMaster hydrolic throwout bearing , and the instruction's indicate , from .030 to .060 thousands of clearense from the T/O bearing o the finger's. With a 1/2 travel multiplied by the fork length of say 4 inches that should be enough travel. I have a camero manuel , I'll check to see if I can find that clearense requirement. Quote Link to comment Share on other sites More sharing options...
fastzcars Posted June 1, 2004 Share Posted June 1, 2004 Hi Mas8230, I just found my chilton manuel for 82 to 88 camero. It said's "Before removing the hydrolic components for repair,remove the clutch housing dust cover to verify the malfunction. Measure the movement of the slave cylinder push rod by pushing the clutch pedal to the floor; the minimum movement should be 14mm. Do not replace the cylinder if its movement exceeds the minimum." Inanother part of the manuel it saids " The diaphragm spring type clutches used are available in two differnet designs: flat diaphragm springs or bent springs. The bent fingers are bent back to create a centrifugal boost ensuring quick re-engagement at highwer engine speeds. This design enables pressure plate load to increase as the clutch disc wears and makes low pedal effort possable even with a heavy duty clutch. The throwout bearing design is 1 1/4" long an i shorter than the bearing used with the flat finger clutch." In short maybe the throwout bearing is the wrong one. This happened to me a few years back when I replaced my nissan's truck clutch.The clutch I oder'd through Kragen had too short of a bearing , compared to the stock one. Even the Kragen's manager conseaded that the bearing was wrong when I showed him the stock and the one that they sold me. They even oftered to pay for a new nissan throwout bearing. Quote Link to comment Share on other sites More sharing options...
GAZRNR Posted June 1, 2004 Share Posted June 1, 2004 I'm using the JTR T5 slave cylinder converted per JTR on a T56 with 7/8 master. I had a problem getting the air out of the system...your problem sounds like air in the system too. I solved my problem by jacking the back of the car way up to help get the air towards the bleeder in the slave cylinder. Once I bleed this way the clutch was right where I wanted it. Give it a try. Quote Link to comment Share on other sites More sharing options...
THUNDERZ Posted July 6, 2008 Share Posted July 6, 2008 I Have bled and bled and bled for over an hour, and I still can hardly get any push rod travel on my slave sylinder, maybe 3/8" at the most! I have a Howe 7/8" master cylinder, and did the "re-working" of the slave exactly as JTR. Even better, I have an aluminum slave. But I cannot get any movement at the fork. This is the only thing keeping me off the road. EVERY part is brand new. Any ideas, suggestions, etc.? What is the "re-working" of the slave cylinder? Quote Link to comment Share on other sites More sharing options...
fastzcars Posted July 8, 2008 Share Posted July 8, 2008 Have you checked the date of the original post? It's FOUR YEARS OLD!!!!! Time to put it to rest. LOL Quote Link to comment Share on other sites More sharing options...
THUNDERZ Posted July 9, 2008 Share Posted July 9, 2008 Have you checked the date of the original post? It's FOUR YEARS OLD!!!!! Time to put it to rest. LOL Hey I was just using the search button so I didnt get yelled at Quote Link to comment Share on other sites More sharing options...
pparaska Posted July 9, 2008 Share Posted July 9, 2008 THUNDERZ did exactly what we want people to do - search, find the most relevant thread they can on their topic, and add to that thread! I admit it's difficult finding the most relevant thread, but I definitely appreciate the effort! In fact, using an old relevant thread will make future searching easier on the next people that search on a particular topic like this one!!!! BRAVO, ThunderZ!!! Now, for some added tech content. One thing I've learned with bleeding hydraulic clutch stuff (mostly hydraulic release bearings), is that you should just take the bleeder out of the hose and let it gravity bleed first. If it needs help, then do the push-pedal-down-once thing as usual, but do it with the bleeder very loose or removed. Then when the pedal is down, return the bleeder to the hose end and snug it good as usual as the pedal goes up. I also found that sometimes it's good to push the pedal down quickly with the bleeder out to get the large air pockets in the HRBs to collect, break free of the surface (tension) of the innards of the HRB fluid reservoirs, etc. But only do this if you are not getting a firm pedal after a bunch of bleeding. But then be sure to let the air settle out for a while (not sure how long) and then go back to bleeding with the bleeder just slightly cracked whle the pedal is going down (and of course closed going up) to get any tiny bubbles created during the fast pedal bleeding out of the system. This method should not be needed for external/accessible slave cylinders, as you should be able to rap on that cylinder to get the bubbles to break free of the surface tension holding them to the innards of the slave cylinder, so that they go out the bleed port/screw. Quote Link to comment Share on other sites More sharing options...
THUNDERZ Posted July 11, 2008 Share Posted July 11, 2008 THUNDERZ did exactly what we want people to do - search, find the most relevant thread they can on their topic, and add to that thread! I admit it's difficult finding the most relevant thread, but I definitely appreciate the effort! In fact, using an old relevant thread will make future searching easier on the next people that search on a particular topic like this one!!!! BRAVO, ThunderZ!!! Now, for some added tech content. One thing I've learned with bleeding hydraulic clutch stuff (mostly hydraulic release bearings), is that you should just take the bleeder out of the hose and let it gravity bleed first. If it needs help, then do the push-pedal-down-once thing as usual, but do it with the bleeder very loose or removed. Then when the pedal is down, return the bleeder to the hose end and snug it good as usual as the pedal goes up. I also found that sometimes it's good to push the pedal down quickly with the bleeder out to get the large air pockets in the HRBs to collect, break free of the surface (tension) of the innards of the HRB fluid reservoirs, etc. But only do this if you are not getting a firm pedal after a bunch of bleeding. But then be sure to let the air settle out for a while (not sure how long) and then go back to bleeding with the bleeder just slightly cracked whle the pedal is going down (and of course closed going up) to get any tiny bubbles created during the fast pedal bleeding out of the system. This method should not be needed for external/accessible slave cylinders, as you should be able to rap on that cylinder to get the bubbles to break free of the surface tension holding them to the innards of the slave cylinder, so that they go out the bleed port/screw. Thanks Pete...that gives me a couple new things to try. I went out and blew some money on an aluminum slave with an actual bleeder nipple, and a "quick disconnect" by mcleod so I wouldnt have to tap a plastic slave, and a new SS hose. It was pretty disappointing to have it act the same way after all of that. Its really frustrating to have something this simple be so hard. I have never had so much trouble with a clutch hydraulic system. Quote Link to comment Share on other sites More sharing options...
mas8230 Posted September 18, 2008 Author Share Posted September 18, 2008 I started the post four years ago, WOW !!! Since then, I threw in the towel on the hydraulic slave setup. When I had the motor out a while back I installed a hydraulic throwout bearing. That was the ticket !!! Money well spent !!! It did take a while to bleed at first. However, I adjusted the length of the pushrod between the pedal and master. Once I did that, I got the air out, the system bled, and it works great. It's been like that for over a year with no problems !!!! Quote Link to comment Share on other sites More sharing options...
THUNDERZ Posted September 18, 2008 Share Posted September 18, 2008 I started the post four years ago, WOW !!! Since then, I threw in the towel on the hydraulic slave setup. When I had the motor out a while back I installed a hydraulic throwout bearing. That was the ticket !!! Money well spent !!! It did take a while to bleed at first. However, I adjusted the length of the pushrod between the pedal and master. Once I did that, I got the air out, the system bled, and it works great. It's been like that for over a year with no problems !!!! I had the motor out on mine as well and I let it hang on the line for a week and when I tried it again it worked much better...like the air had come up out of it which is just stupid that these things are so hard to bleed. I have bled many other slave cylinders ONCE! and they worked perfect. Dont get it. Glad you found your solution. Quote Link to comment Share on other sites More sharing options...
gvincent Posted September 19, 2008 Share Posted September 19, 2008 I have the exact same set-up, T56 with the T5 aluminum slave, the 7/8" Tilton, a SS braided cable AN-4 and the GM quick-connect to AN adaptor McCleod ($35!!!), It was a bitch to bleed and after trial and error found the O ring seal on the AN adaptor was not seating properly in the slave. I had gotten frustrated and let it sit for a week and noticed a few fluid drops on the quick-connect adaptor and garage floor. I ground the end of the McCleod adaptor down a tiny bit and it then seated correctly. Oh and don't loose that damm roll pin for the GM Quick-connect adaptor, they are impossible to find, not even at the GM dealer! There is nothing "quick" about these fittings, they suck, at one point I was even thinking about drilling and taping the quick-connect opening on the slave for an -AN fitting. Whoever invented these fittings should be shot along with the GM fuel injection fittings, but that is another story. I have to pull the motor and tranny out again but I will remove the slave from the tranny and leave it all connected this time. I don't want to go through bleeding again. Also bleed the Master first it helped alot, but watch out for your newly painted engine bay, use plenty of rags Greg I had the motor out on mine as well and I let it hang on the line for a week and when I tried it again it worked much better...like the air had come up out of it which is just stupid that these things are so hard to bleed. I have bled many other slave cylinders ONCE! and they worked perfect. Dont get it. Glad you found your solution. Quote Link to comment Share on other sites More sharing options...
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