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How do I tell the difference between bad master cylinder and bad slave cylinder?

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Old 02-17-2011, 12:20 AM
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Exclamation How do I tell the difference between bad master cylinder and bad slave cylinder?

Saturday I noticed I had to push clutch most the way down before it would catch than normal and gear shifting harder. Sunday I checked reservoir, it was low, so refilled. It was fine for a bit, clutch pedal returned mostly to normal, and it was like driving my old truck again. Then it became harder once more as the few days and miles passed, roughly 45 (miles) of them. However the fluid has not dropped any as in not in the slightest. Under the truck too, there is no signs of leaking. Leading me to believe air got in the system when it was low.

As a result, today went to gravity bleed, however the fluid barely came out and then stopped altogether. Tried pumping the clutch and all that, and just hit the floor. Truck is nearly impossible to shift now, without first shutting it off and then putting into gear.

Is there an easy way to tell if it is the slave cylinder or if it is the master cylinder...etc? As I can replace the master at home, however the slave cylinder is internal requiring a tranny drop and would have to go to the shop.

Thanks

Last edited by darkly96; 02-17-2011 at 12:23 AM.
Old 02-17-2011, 12:27 AM
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Bad master cylinder will be leaking on the inside of the firewall (under the driver side dash board), or on the motor compartment side of the fire wall. And if the slave cylinder is bad, then the bell housing will be wet on the bottom of it.

Last edited by 1996 Redneck F150; 02-17-2011 at 12:53 AM.
Old 02-17-2011, 12:47 AM
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a master cylinder is for brakes. if you can pump them up to get your pedel but the pedel won't stay up (while applying braakes), then it is probably bad. Inside seals could go bad, thus passing the fluid and never actually leak. Of course, leaks is one of the first thing you should look for.
slave cylinder is for your clutch. Look for leaks
Old 02-17-2011, 12:52 AM
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Originally Posted by Delmarosalinda
a master cylinder is for brakes. if you can pump them up to get your pedel but the pedel won't stay up (while applying braakes), then it is probably bad. Inside seals could go bad, thus passing the fluid and never actually leak. Of course, leaks is one of the first thing you should look for.
slave cylinder is for your clutch. Look for leaks
Umm, the clutch has a master cylinder to. What do you think holds the clutch fluid? lol
Old 02-17-2011, 12:58 AM
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Originally Posted by 1996 Redneck F150
Bad master cylinder will be leaking on the inside of the firewall (under the driver side dash board), or on the motor compartment side of the fire wall. And if the slave cylinder is bad, then the bell housing will be wet on the bottom of it.
Thats what I don't get the fluid isn't going anywhere level wise and I'm not seeing any leaks. Any way I could of just got low on fluid and then air got in the system, and that is mainly the problem? Just I read into slave cylinders and for most cases if the slave is bad, then your fluid level drops and it should be coming out of the bell housing like you stated. However its not so thats why I was thinking master or air in system? I really don't know, hence asking, just guessing

and delmarosalinda, as been pointed out, your clutch has a master cylinder too.

Last edited by darkly96; 02-17-2011 at 01:04 AM. Reason: added question
Old 02-17-2011, 01:03 AM
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Originally Posted by darkly96
Thats what I don't get the fluid isn't going anywhere level wise and I'm not seeing any leaks. Any way I could of just got low on fluid and then air got in the system, and that is mainly the problem?

and delmarosalinda, as been pointed out, your clutch has a master cylinder too.
If I'm not mistaken, there should be lines going to the slave cylinder. I'm not sure though because I haven't had to do any tranny work on my truck, YET. It HAS to either be the slave, master cylinder, or maybe the lines. Read up on this thread, https://www.f150forum.com/f10/bleeding-clutch-11334/, re-bleed your clutch system, and see what happens.
Old 02-17-2011, 01:36 AM
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Originally Posted by 1996 Redneck F150
If I'm not mistaken, there should be lines going to the slave cylinder. I'm not sure though because I haven't had to do any tranny work on my truck, YET. It HAS to either be the slave, master cylinder, or maybe the lines. Read up on this thread, https://www.f150forum.com/f10/bleeding-clutch-11334/, re-bleed your clutch system, and see what happens.
cant get fluid from master cylinder to slave cyliner with out lines...lol
Old 02-17-2011, 01:49 AM
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Last edited by 1996 Redneck F150; 02-17-2011 at 01:52 AM.
Old 02-17-2011, 01:50 AM
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Originally Posted by Delmarosalinda
cant get fluid from master cylinder to slave cyliner with out lines...lol
According to you, there's no master cylinder for the clutch, so there must be no fluid
Old 02-17-2011, 08:42 PM
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Wink

The massa cylinder is white and the slave cylinder is black -- no really!

Be advised that you CAN have a clutch master cyl. failure WIHTOUT loosing fluid -- the piston can get stuck inside the cylinder so it doesnt pump the fluid porpely but you still show a proper fluid level...

this happened to me twice on mah miatas

just a tidbit of info that might help you



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