Air In The Hydraulic Clutch System But No Leaks For The Cylinders

[redwolf624]

day before christmas eve i decided to clean my clutch slave cylinder cause when i try to go into first or second i gotta grind gears just to get into that gear but 3, 4, and 5 would be smooth as glass, today me and my dad tried to tackle the clutch again cause after bleeding it i had no clutch to where if i start the jeep in neutral but try to go into any gears it was impossible, my clutch slave and master cylinder are good, no leaks but if ya press the pistion in on the clutch slave air burps outta the master cylinder which tells me i have air in the system some how, where could it be comin in at?

 

Redwolf

[Jeep Driver]

Just cause it ain't leaking does not mean it's good.

 

My master was weak........did not leak.

 

Now the one I replaced it with 14 months ago leaks but works great......I have one on order and should be in tomorrow.

 

I assume you have an external? Does it have a bleed screw?

[redwolf624]

Just cause it ain't leaking does not mean it's good.

 

My master was weak........did not leak.

 

Now the one I replaced it with 14 months ago leaks but works great......I have one on order and should be in tomorrow.

 

I assume you have an external? Does it have a bleed screw?

externally mounted clutch slave cylinder yes and it does have a bleed screw however i can't see or find a bleed screw for the master cylinder,

 

Redwolf

[Eagle]

It's a closed system -- if there's air in it, it leaks. There are three components where it can leak -- the master cylinder, the slave cylinder, and the hose/line that connects the first two.

 

How did you bleed the clutch system?

[redwolf624]

It's a closed system -- if there's air in it, it leaks. There are three components where it can leak -- the master cylinder, the slave cylinder, and the hose/line that connects the first two.

 

How did you bleed the clutch system?

the way the haynes manual says, gravity bled, and the way my dad used to do it when he way a kid, so purdy much everyway possible,

 

Redwolf

[Eagle]

 

 

How did you bleed the clutch system?

the way the haynes manual says, gravity bled, and the way my dad used to do it when he way a kid, so purdy much everyway possible,

 

Redwolf

 

I don't have a Haynes manual, so that tells me nothing. And I have no idea how your father used to do it when he was a kid.

 

There are many wrong ways to do it, and only one correct way. Since you started out being able to shift into the higher gears and ended up not being able to get ANY gear, obviously you went backwards and did something to make it worse. We can't tell you if what you did was right or wrong if you don't tell us what you did.

[Jeep Driver]

His master is not pushing enough fluid to disengage the clutch completely, that's why going into 1st is difficult.......synchros into 2 are going out.

 

Sychros into 3 and 4 and 5 and good and he does not notice the clutch not fully disengaging.

 

I have no idea where he is sucking air at....my guess is the O-rings are dried out or torn or.....?

 

Also, he could have a weak hard line that is soft and expanding or it could be cracked.......but somewhere I would think he'd leak fluids. But my guess is the plunger on his master is passing fluid and it just has not begun to leak out the back yet.

 

 

I bench bled the master, gravity bled the slave.......and pump the $#!& out of it for about 2 minutes........rock solid after that.

[redwolf624]

His master is not pushing enough fluid to disengage the clutch completely, that's why going into 1st is difficult.......synchros into 2 are going out.

 

Sychros into 3 and 4 and 5 and good and he does not notice the clutch not fully disengaging.

 

I have no idea where he is sucking air at....my guess is the O-rings are dried out or torn or.....?

 

Also, he could have a weak hard line that is soft and expanding or it could be cracked.......but somewhere I would think he'd leak fluids. But my guess is the plunger on his master is passing fluid and it just has not begun to leak out the back yet.

 

 

I bench bled the master, gravity bled the slave.......and pump the $#!& out of it for about 2 minutes........rock solid after that.

how do ya bench bleed the master?

 

Redwolf

[Jeep Driver]

You'll likely never get the pin out with the master still on the truck, so you'll have to take the master off.

 

Fill the reservoir with fluid and pump it by hand until the fluid spills out of the hole for the line out, pump a couple of short pumps to get the air out of the pump, put the cap back on, reinstall. Then gravity bleed the line, making sure the reservoir does not empty. Tighten the bleed screw or reinstall the line to the slave. Pump the pedal for a minute or so the get any air out of the slave and line, top off your master.

[Jeep Driver]

Here is another thing you might try-

 

Remove the line from the slave, see if you can pull the line up into the engine bay so that the end of the line is above the master. Have someone slowly pump the clutch pedal and push the air out of the line, let the fluid run into a cup or jar, do this until all of the air is out of the line and pump. Then put a vacuum line cap on the end of the line and drop the line back down to the trans.

Take the slave and put the line end down in a jar of fluid and push the rod in and out a couple of times to get the air out of the slave, reinstall the line to the slave and reinstall the slave.

 

 

If you have air trapped in your line....your master may not have enough stroke to get the air out and gravity bleeding may not be enough....by doing what I suggested you are making certain that no air can be trapped in the line.

 

If you still have air in the system......you have a leak somewhere......consider replacing the entire system.

[carnuck]

One issue I ran into was where it felt like the clutch master was running out of fluid when it wasn't. Previous owner changed the master and slave twice (2.5L '86) and gave up. I took a lid from an old master and drilled it for a tire valve (metal one for mags) then used my tire pump to add pressure while I opened the bleeder. That forced the seals tight to the walls and lasted about 6 months then it needed bleeding again.

   That master lasted about 3 years then quit. The next one didn't last 6 months. When I was under the dash undoing the rod I noticed the pedal wasn't pushing straight. I bent it so it was straight and didn't need to replace the master, but the pedal snapped off a couple weeks later. I put the one from my current Comanche in because I was switching to auto at the time and it was fine till I sold it 2 years ago. 

[Oyaji]

One issue I ran into was where it felt like the clutch master was running out of fluid when it wasn't. Previous owner changed the master and slave twice (2.5L '86) and gave up. I took a lid from an old master and drilled it for a tire valve (metal one for mags) then used my tire pump to add pressure while I opened the bleeder. That forced the seals tight to the walls and lasted about 6 months then it needed bleeding again.

   That master lasted about 3 years then quit. The next one didn't last 6 months. When I was under the dash undoing the rod I noticed the pedal wasn't pushing straight. I bent it so it was straight and didn't need to replace the master, but the pedal snapped off a couple weeks later. I put the one from my current Comanche in because I was switching to auto at the time and it was fine till I sold it 2 years ago. 

 

I like reading your posts because you often come up with unusual solutions by thinking "outside the box". Whereas most folks just change parts, you look at the bigger picture and try to find a fix for the underlying cause for failure, as you did here.

 

 Thanks for sharing.

[Jeep Driver]

 

One issue I ran into was where it felt like the clutch master was running out of fluid when it wasn't. Previous owner changed the master and slave twice (2.5L '86) and gave up. I took a lid from an old master and drilled it for a tire valve (metal one for mags) then used my tire pump to add pressure while I opened the bleeder. That forced the seals tight to the walls and lasted about 6 months then it needed bleeding again.

   That master lasted about 3 years then quit. The next one didn't last 6 months. When I was under the dash undoing the rod I noticed the pedal wasn't pushing straight. I bent it so it was straight and didn't need to replace the master, but the pedal snapped off a couple weeks later. I put the one from my current Comanche in because I was switching to auto at the time and it was fine till I sold it 2 years ago. 

 

 

 

I like reading your posts because you often come up with unusual solutions by thinking "outside the box". Whereas most folks just change parts, you look at the bigger picture and try to find a fix for the underlying cause for failure, as you did here.

 

Thanks for sharing.

 

 

You ever have to drive 5 miles through town with no clutch?

 

It is an adventure.

 

 

 

 

I guess it depends on who's box you are outside of..huh?

[Oyaji]

Actually, yes, yes I have. Back in college days when I broke the clutch cable on my 914 and the replacement took 6 weeks to arrive, I drove daily to school 47 miles each way (a third of that in town) with no clutch. It taught me the art of "strategic parking": seeking out parking spaces with a slight downhill so the car was easier to push fast enough so I could slip it into first gear with the engine running. Already knew the art of driving without ever touching the brake pedal (from driving 32,000-pound GVW trucks, overloaded with no functional brakes, starting at age 12), reading the traffic and signals far enough ahead so I didn't need to stop... Thanks for triggering those memories! :) That experience also prompted me to fashion a dirt shield to protect the clutch cable at its exit from the sheath from abrasion by the dirt and mud that accumulated from driving down 2 miles of bad dirt road in all weather just to get to the nearest paved road.

 

Thinking outside the box is often the source of inspiration for novel solutions to problems never considered by engineers responsible for the original design, and I encourage everyone to share as much as they are comfortable offering (wouldn't want anyone to jeopardize any possible profit opportunity by undermining "patentability"!), regardless of how simple or off-the-wall they may seem at first glance.

[carnuck]

 

 

One issue I ran into was where it felt like the clutch master was running out of fluid when it wasn't. Previous owner changed the master and slave twice (2.5L '86) and gave up. I took a lid from an old master and drilled it for a tire valve (metal one for mags) then used my tire pump to add pressure while I opened the bleeder. That forced the seals tight to the walls and lasted about 6 months then it needed bleeding again.

   That master lasted about 3 years then quit. The next one didn't last 6 months. When I was under the dash undoing the rod I noticed the pedal wasn't pushing straight. I bent it so it was straight and didn't need to replace the master, but the pedal snapped off a couple weeks later. I put the one from my current Comanche in because I was switching to auto at the time and it was fine till I sold it 2 years ago. 

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I like reading your posts because you often come up with unusual solutions by thinking "outside the box". Whereas most folks just change parts, you look at the bigger picture and try to find a fix for the underlying cause for failure, as you did here.

 

 Thanks for sharing.

lockquote>

 

 

You ever have to drive 5 miles through town with no clutch?

 

It is an adventure.

 

 

 

 

I guess it depends on who's box you are outside of..huh?

 

HAHAHAHAHAHAHAHAHAHAHA! Try driving from 1/2 way between Seattle, WA and Ouray, CO and back (FSJ invasion. UPS lost the steering parts for my '84 J10 so we converted the Comanche to 4x4 and left the same day) up into the mountains (I gave up 1/2 way up Big Bear) and back. All because NO-ONE had an external slave cyl for an '86 MJ. I'd fill the master and get maybe 3 shifts before it was empty again. It didn't help I rolled over the scale at 6,000lbs on the way with the canopy, camping gear, spare parts (no clutch slave. Go figure?) and 2 teenagers.

   We ended up stuck in the desert for 8 hours because of a strike by the Utah government employees union. 103F in the shade and there wasn't any! A woman died from the heat in the lineup and last I heard they were sued over that. Also we were hit by a delivery truck from the company I worked for that knocked my alignment out and caused my first run in with death wobble. We destroyed all 3 spare tires and the 4 on the truck getting home (sunday).

[Jeep Driver]

One issue I ran into was where it felt like the clutch master was running out of fluid when it wasn't. Previous owner changed the master and slave twice (2.5L '86) and gave up. I took a lid from an old master and drilled it for a tire valve (metal one for mags) then used my tire pump to add pressure while I opened the bleeder. That forced the seals tight to the walls and lasted about 6 months then it needed bleeding again.

   That master lasted about 3 years then quit. The next one didn't last 6 months. When I was under the dash undoing the rod I noticed the pedal wasn't pushing straight. I bent it so it was straight and didn't need to replace the master, but the pedal snapped off a couple weeks later. I put the one from my current Comanche in because I was switching to auto at the time and it was fine till I sold it 2 years ago. 

 

 

I replaced mine yesterday, new one has not lasted 24 hours and now it leaks.

 

I did notice the same thing about the pedal not being in line with the master and the rod not going straight in.

 

I'm ordering one last one and I'll bend the rod as you did......we'll see.

[redwolf624]

ordered a new slave cylinder today so i can pick it up tomorrow on payday, i did noticed some fluid drippin out of the slave cylinder and my slave cylinder has been questionable ever since i replaced my clutch and bleed it the first time, hopefully tomorrow when i get the cylinder it'll fix all my problems,

 

Redwolf

[redwolf624]

replaced the slave cylinder today, clutch works again :) i just don't like the catch point at the top, i like'd it at the bottom near the floor,

 

Redwolf