Slave cylinder overextended?? 3800 w/F40 (Page 3/3) thelinsells DEC 31, 04:32 PM Please take what I about to say with a grain of salt or an aspirin .F 40 does not have a slave cylinder.It has a hydraulic through out bearing.If the F40 came with the little black "Y" thing,you will need one.It is your auto bleeding system.This little black "Y" thing plugs into the clutch at the bellhousing.If hydraulic fluid came out of the bellhousing then the trough out bearing is ruptured, and you need a new one. Daryl M JAN 01, 01:25 AM I was concerned about this very thing with my LFX/F40 setup. TheFierp clutch master cylinder piston diameter is significantly larger that the clutch master cylinder used in vehicles that came with an F40. This means that the Fiero master pumps more fluid. That has the potential to do 2 things. 1. Make the clutch pedal harder to push. 2. Overextended the hydrolic throw out bearing. I am trying using a Saab master cylinder. I posted about it on my thread https://www.fiero.nl/forum/...2/HTML/142132-1.html It is on the second to last page. Daryl M JAN 06, 12:33 AM quote Originally posted by dnthmn87: The spacer I found was from ZZP and goes between the back of slave cylinder and the transmission. I made an addition spacer to go with that one to achieve a .21 air gap. I also added a bump stop to the pedal as I felt the travel was too far. Put it all back together and bled the pedal successfully without blowing out the slave(thankfully). Started the car and pushed the clutch pedal in and it makes a terrible vibrating/grinding sound! It makes the sound when its barely pushed in at all.... Brand new slave/throwout bearing. I'm about ready to set this car project on fire and claim the insurance money After reading your posts again, I still don't know what master cylinder you used. Do you know what car it was made for and the piston diameter? dnthmn87 JAN 07, 11:53 PM Master cylinder is from an 89 Pontiac grand prix, my first setup was with the 5 speed/282 getrag from that car. That master is new as is the HTOB/Slave unit. Yes I have the Y shaped connector that plugs into what Ive been calling the slave cylinder aka HTOB. This time its not blown out, but I believe Ive added too many spacers because now when its bolted together the clutch is disengaged. I went back out after my last post to try putting it gear despite the awful noise, and when I let out the clutch nothing happens. In fact with the clutch pedal released I can shift gears while the car is running.... I don't understand how i'm so off while doing the air gap measurements to determine how much spacing I need. But either way i'm pretty sure the pedal had too much travel which was why I was overextending the TOB. Gonna tear it apart for the 3-4th time (lost track how many times) and re-measure the air gap and hopefully get the right spacer in there and with the bump stop in place it SHOULD finally work out.... Anyone have a guess as to how much spacer I'll likely have to remove to NOT have the clutch disengaged when bolted together? I've got a .25" and a .10" Daryl M JAN 08, 02:06 AM quote Originally posted by dnthmn87: Master cylinder is from an 89 Pontiac grand prix, my first setup was with the 5 speed/282 getrag from that car. That master is new as is the HTOB/Slave unit. Yes I have the Y shaped connector that plugs into what Ive been calling the slave cylinder aka HTOB. This time its not blown out, but I believe Ive added too many spacers because now when its bolted together the clutch is disengaged. I went back out after my last post to try putting it gear despite the awful noise, and when I let out the clutch nothing happens. In fact with the clutch pedal released I can shift gears while the car is running.... I don't understand how i'm so off while doing the air gap measurements to determine how much spacing I need. But either way i'm pretty sure the pedal had too much travel which was why I was overextending the TOB. Gonna tear it apart for the 3-4th time (lost track how many times) and re-measure the air gap and hopefully get the right spacer in there and with the bump stop in place it SHOULD finally work out.... Anyone have a guess as to how much spacer I'll likely have to remove to NOT have the clutch disengaged when bolted together? I've got a .25" and a .10" Here is the problem in a nutshell. The master cylinder you chose has a piston diameter of about 22mm. The HTOB you are using is designed to work with a piston diameter of 15mm. Your master cylinder pushed over twice as much fluid as is called for. By comparison, the stock Fiero master cylinder has a piston size of 17mm. Although it does push 30 % more fluid than is called for, it can be spaced out to kinda work, although not as designed. The master cylinder used on the 2006 Saab 9-3 (also used on the 2014 Buick Verano) has the correct size piston, but requires adapting for the hydraulic line and linkage (see my setup as noted in previous comment above). Good luck whatever you decide to do.