Hi all I thought I had the air all bled out of the clutch system but it just keeps coming back. I bled it all ways and the proper way and I get loads of travel but it doesn't stay for long. When I bought the car last fall there is a new master cylinder and lines but the slave is not. Questions a) Is it possible that the clyinder is sucking in air b) Is it possible that the bleeder valve is sucking in air
The slave cylinder uses an umbrella seal...this apparently lets air in without always leaking oil out. Just changed mine for the exact same problem. Works great now! Use the Rodney Dickman slave cylinder if possible. It uses a double seal.
The culprit could be the bleeder valve, or the slave cylinder seal, or both. As mentioned above, Rodney Dickman sells an aluminum slave cylinder that puts the parts store units to shame. He also sells rebuild kits for your existing slave cylinder that use the double seal. But in order for that to work, the cylinder bore in your slave cylinder needs to be free of defects (no rust pitting, wear marks, etc).
Pull the boot off the slave cylinder pushrod to see if you have fluid in there. It will hold a lot of fluid before it starts to leak out. If it's leaking, you have 3 options.
Order a slave rebuild kit for an 85 Toyota MR2 from your local auto parts store and install it into your slave housing. Order a slave rebuild kit from Rodney Dickman. Order a Rodney Dickman Isuzu slave cylinder.
To bleed the system:
The floor often isn't wet if the MC is leaking. The fluid runs down the front bulkhead and goes underneath the carpet. You would need to feel around the area where the pushrod comes through, in order to find it. Since yours is new, it probably isn't the problem.
This is a one person job so no helper is needed. Pumping the clutch pedal to bleed the system will break up air bubbles into little small ones. Small ones can cling to the walls of the tubing and coagulate later. Pressure or gravity bleeding is the best way to bleed the system. If you don't have a pressure bleeder, try this.
Lift the front left wheel off the ground. It doesn't matter how high. It should just be off the ground. A floor jack is preferred. The left front of the car should be the highest point. Fill the MC reservoir all the way to the top and leave the cap off. Keep an open can of fluid nearby. Open the bleeder valve on the slave cylinder enough that the fluid begins to flow out. If you're using a hose on the nipple, be sure it's a clear hose so you can see if there are any air bubbles coming out or you can submerge the end of the hose into a glass container with a small amount of fluid. While the fluid flows through the system, give an occasional rap on the side of the slave, using a heavy object like the handle of a ratchet. Keep watch on the MC reservoir and as it nears the bottom, refill it. Don't allow it to run dry. If it does, start again with refill # 1. Continue this process until you've filled the reservoir for the 3rd time. As the fluid level reaches the FULL mark on the reservoir, close the slave bleeder valve. Replace the MC reservoir cap.
Now, it may be possible that you're cooking the fluid in the hydraulic line. Look at the line where it comes up to the slave cylinder and notice how close it comes to the coolant hose or exhaust area. Get yourself a length of the plastic wire loom cover of the type used to cover parts of your wiring harnesses. Slide it all the way down over the fluid line until it stops, cut it off just beneath the slave. This will act as an insulator and heat sink to keep the fluid from boiling.
I bled it the last couple of times the way you said and it only lasts a short time. I just ordered one from Rodney Dickman, so we will see how that goes. Will keep you posted!!
But seriously, all you have to do is install it and bleed it.
I forgot to mention this before, but have you checked for a wet spot on the driver's side carpet, under the dash? If the master cylinder is leaking, that's usually where the fluid goes to.
Yes I have checked and all that is good. It doesn't go down fluid just air gets in the slave cylinder about every 150+ klms, bleed it get about 1 1/4 inch travel and then shortly after it needs to be bled again.
My system had air in the slave cylinder too. I unbolted it from the transmission and tilted it so the bleeder was up. When I opened the bleeder some bubbles started coming out. When the bubbles stopped I closed the bleeder. The clutch has been great ever since then. The pushrod end of the cylinder must be higher than the other end on mine and when I would bleed it some air was trapped at the other end.
My system had air in the slave cylinder too. I unbolted it from the transmission and tilted it so the bleeder was up. When I opened the bleeder some bubbles started coming out.
I suspect it's easier and just as effective to open the bleeder and push the slave rod in as far as it will go, and then close the bleeder before releasing the rod. IMO, that's the best way to get that trapped bit of air out of the slave.
I suspect it's easier and just as effective to open the bleeder and push the slave rod in as far as it will go, and then close the bleeder before releasing the rod. IMO, that's the best way to get that trapped bit of air out of the slave.
I agree. The vacuum created draws fluid from the master cylinder reservoir and fills the void. If you then do it a second time, that ensures all remaining air is out.
Yes I agree with Patrick that is the best way. I tried in the past to push on the clutch and bleed, etc. it's not as effective as jacking the front of the car up about 4 feet..lol. You really get a good flow when it's up high...not that high but you know what I mean. This way no chance of creating small bubbles or anything.
I've not had great results with the method where you press the slave rod in manually...
I've seen the situation where you press the rod in and bubbles come out (as you would expect), but then when you release the rod, the vacuum created behind the piston does NOT pull fluid from the master cylinder reservoir, but instead pulls air in past the slave piston seal. I've had best results when you always keep positive or neutral pressure in the lines. Never a vacuum.
Maybe it's just me, but I've found that the stock single direction seal doesn't do a good job keeping air out when the direction of pressure is reversed.
Single biggest problem is not having the car jacked up some on the drivers side so all the air accumulates under the bleeder screw.
------------------ Rodney Dickman
Fiero Parts And Acc's Web Page: All new web page!:www.rodneydickman.com Rodney Dickman's Fiero accessories 7604 Treeview Drive Caledonia, WI 53108 Phone/Fax (262) 835-9575
I've found that the stock single direction seal doesn't do a good job keeping air out when the direction of pressure is reversed.
That's why the dual-seal piston replacement and/or the dual-seal slave has been so warmly received. It's one of the best "mods" available for a manual Fiero.
Yeah, with the dual seal piston I was able to bleed the slave cylinder easily using the manual piston compression method. No need to jack up the front of the car, or have someone pump the pedal, or any of that.
Yeah, I saw you guys talking about that dual direction seal above and it sounds like it would be a real improvement over stock. I can see how it could make the "push the plunger in method" viable.
Yeah, I saw you guys talking about that dual direction seal above and it sounds like it would be a real improvement over stock. I can see how it could make the "push the plunger in method" viable.
Pushing the plunger should work on any slave cylinder with a good seal. If it doesn't work, then either the seal is bad or there is a restriction on the master cylinder stopping free flow of reservoir.
Update without a pic of the old slave cylinder. I put the new Rodney Dickman slave cylinder in on Sunday and drove it today for the first time and what a difference it made. The car shifts so smooth and I have so much more travel on the piston. I can even feel the clutch is a little bit more stiffer. No trouble bleeding, the only issue was getting the hose off the old cylinder. A little heat from the propane torch and a little skin tore off the knuckle and it came right off. The old cylinder, the piston(whatever you call it) was all corroded and stayed about half way in, it was complete garbage!!
My next one will be from Rodney too. Right now I have an E-bay special that so far is still holding up. When I got my Fiero all the brakes and clutch parts were froze so I went cheap just to get it going.
Hope this question helps someone in the future, quick question on the slave cylinder. Does it go Motor side of the mount, or Trans side of the mount? I ask because the mechanic that put in the old one did it with bolts on both sides and to put it bluntly, i question his ability. I bought the Rodney Dickman Slave and was about to put it on and I just want to do it correctly. Thanks
The Getrag slave is mounted onto studs that are a part of the mount. They point toward the driver's side of the car, so the slave would mount away from the engine. The Isuzu and 4-speed V6 have studs that are a part of the slave and mount from the drivers side into and through the mount.
This is the Isuzu slave. The 4-speed V6 mounts the same way except with a different mount. Nuts are on the engine side of the mount and the slave is on the drivers side of the mount..
This is the Getrag slave. Slave is on the drivers side of the mount.
_3.JPG)
_2.JPG)
