izzo Posted October 8, 2012 Report Share Posted October 8, 2012 working on a 77 king cab. motor/trans rebuilt, new clutch, t/o bearing etc was installed. some time later the clutch system has failed somehow... It wasn't on my truck. But what I do know, is when we pulled the transmission out, the throw out bearing looked like it was worn and dead prematurely. Clutch disc is fine New clutch, new throw out bearing, new master for the clutch etc. Installed everything, dropped the truck and heres the results.. We bled the shit out of the clutch, as far as I can tell there is no more air, as steady streams are coming out now from the slave. However, heres the issues.. The clutch is right on the floor hard to shift the second you lift up your foot its engaging. There isn't much movement from the slave, IIRC its about a half inch give or take.. My thoughts are, that the slave isn't pushing the clutch fork far enough fully releasing the clutch, Making it hard to shift & making it so the clutch is right at the floor. I am thinking possibly there is more air trapped in the line? Wrong clutch fork perhaps? Any thoughts or input would be helpful. As far as I know its the right clutch fork, and the clutch kit was ordered for that year of trans... Pics for shits and giggles... Quote Link to comment
Stupid_fast Posted October 8, 2012 Report Share Posted October 8, 2012 Adjust the plunger at the pedal to go futher into the master cylinder. I had the same issue. Now its gone. Lift up your foot is disengaging ?? wtf ?? Pushing the pedal to the floor disengages the clutch, then releasing the pedal returns it to its clamped engaged state. Quote Link to comment
izzo Posted October 8, 2012 Author Report Share Posted October 8, 2012 What I mean to say is... When you push the clutch pedal in, it has to goto the floor to disengage the clutch, and even then it doesn't feel like its fully disengaging as its hard to shift. While the clutch pedal is on the floor, and you get into gear, the second your foot starts to come up its engaging the clutch so you are going. Quote Link to comment
DISLEXICDIME Posted October 8, 2012 Report Share Posted October 8, 2012 look through the hole for the clutch arm while some one push's it and see if the throw out bearing collar is un clipped on one side and twisting when you push in the clutch . also are the pressure plate teeth warn where the bearing makes contact? did you use the right throw out sleeve for the clutch? did you use the right throw out bearing? Quote Link to comment
izzo Posted October 8, 2012 Author Report Share Posted October 8, 2012 Ill have to have a look see next time i'm over there. Re-surfaced fly wheel, new clutch disc, new pressure plate, new bearing. Sleeve was the one thats already in there, but it was measured up against another throw out bearing out of the same model of transmission and they were identical in size. Quote Link to comment
Stupid_fast Posted October 8, 2012 Report Share Posted October 8, 2012 What I mean to say is... When you push the clutch pedal in, it has to goto the floor to disengage the clutch, and even then it doesn't feel like its fully disengaging as its hard to shift. While the clutch pedal is on the floor, and you get into gear, the second your foot starts to come up its engaging the clutch so you are going. As I said, my setup with roadster clutch 510 disc, 510 slave, 510 master, 510 t/o from dogleg ... The same thing was happening to mine, disengage at the bottom of the pedal normal for new clutch, but should FULLY disengage. Adjust the plunger at the pedal to screw INTO the master cylinder... See if it helps. It fixed mine. There is a lock nut, then turn the rod with pliers or vice grip. Quote Link to comment
datzenmike Posted October 9, 2012 Report Share Posted October 9, 2012 That's an FS5W71B and they aren't set up to use the adjustable clutch arm push rod. The slave push rod should move 1.18". If not then the clutch will be doing exactly as you describe. Put the original master back on and bleed and try it. Quote Link to comment
Big Schlink Posted October 9, 2012 Report Share Posted October 9, 2012 Hey guys thanks for all the help thus far. Izzo has been helping me fix my truck since I've been to busy to get to it. I will give you as much info as I can. It all started out earlier this summer I started to notice the truck was getting harder to shift. Eventually the clutch would not disengage at all. I found a leak between the slave and the clutch hose so I replaced both. At the same time I noticed the fluid in the master was black so I replaced the master as well, in the off chance that someone had put the wrong fluid in and the seals had deteriorated. I bench bled the master before installing it. and purged all the old fluid out of the line and hose by flushing with new fluid. After everything was back together I bled it thouroughly. The clutch was still not working properly. I adjusted the master cylinder clevis fully out away from the floor, the clutch still wasn't working. Upon further inspection I found the clutch fork had come of the pivot inside the tranny. At this point I decided to pull the tranny and replace the clutch. once everything was apart I found that the T/O bearing was leaking grease, when it was removed from the carrier it fell apart completely. So Izzo gets everything done while I supervise from my chair next to the truck. We go for a test drive and all seams well at first, but then things get hard to shift. The clutch would not disengage unless the pedal was fully on the floor. I removed some insulation from under the carpet with no improvement. I tried screwing the master cylinder clevis in towards the floor and the clutch would not disengage at all. At this point the pedal feels soft again and the clutch will not release. It seams like there is still air in the system or air is somehow getting back into the system. This is a 1977 620 KC with an L20B and a 5 speed (FS5W71B) all parts have been ordered by make/model/year, and compared against old to ensure they are correct for the application. Quote Link to comment
datzenmike Posted October 10, 2012 Report Share Posted October 10, 2012 Peddles Should be adjusted so that the rubber pad is 6.5" from the floor. Adjust the peddle stop bolt. Adjust the peddle free play to 3 or 4mm about 1/16" to 1/8" by turning the master cylinder push rod in or out. Push down on the peddle with your thumb until there is resistance from the master. The peddle should have a small clearance between it's fully up position and when the push rod contacts the master cylinder. Quote Link to comment
izzo Posted October 10, 2012 Author Report Share Posted October 10, 2012 We power bled the system. Still issues... Swapped out the master and was able to get double the fork movement. It's shifting easier like it should, its fully disengaging and the clutch isn't on the floor. Everything seems to be as it should. Quote Link to comment
Eagle_Adam Posted October 10, 2012 Report Share Posted October 10, 2012 winning!!! now onto the next truck :devil: Quote Link to comment
izzo Posted October 10, 2012 Author Report Share Posted October 10, 2012 winning!!! now onto the next truck :devil: Right!! Hopefully getting her tonight or tomorrow. Ill take pics and post once she arrives Quote Link to comment
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