My clutch went out on me and after checking it out,the slave cylinder wasnt working.There are no leaks anywhere inside or out.I tried bleeding the system but it wouldnt work.I rebuilt the slave and bled it.It looks like all fluid but it wont work.Can the clutch master cylinder be bad and not leak?Would the system still attemp to bleed?Any help is appreciated.Thanks.

 

Sounds like the master cylinder needs to be bleed itself.

 

the master and the slave cylinders are basic hydraulic cylinders

the internal seals of the cylinders can go bad and cause the pressure to bleed internally and not push enough pressure through to release the clutch

you will be able to bleed the system, because the seals are still holding up enough to push fluids through the lines when there's no real force stopping it (because you have the bleed valve open), but once you close the system and force that moving fluid to cause pressure, that pressure can bleed pass the internal seals, and cause the intire system to not work

I see it at work all the time; after so many 100s of cycles, the cylinders on our cranes have internal seals give out gradually, and they "bleed down", or collapse ever so slowly, with no external leaks the majority of the time



short answer to your question; yes, the master cylinder can in fact be bad and show no external leaks



but, before just saying "oh it's the master cylider", remove the line and try to bench bleed the master cylinder without the line hooked up; you may just have an air pocket trapped at the cylinder

 

Thanks a million IAMSUPERBLEEDER and BIGBLUEPILE.That is exactly what I needed to know.Im going to rebuild or replace the clutch master anyway.I have a strong feeling that is the problem.

 

you're welcome

 

get someone to help you look; push in and out on the pedal, and see if the slave fork moves, at least an inch, and then see if the slave piston moves, at least an inch. If the piston moves, you know the fork is moving, if the fork moves, but the piston doesn't, then your slave cyl is bad. if the fork doesn't move, you could have a bad clutch bracket, inside on the floorboard; cracked around the edge of it somewheres...

 

I've got the engine out in my '84 pickup and will be putting in a new clutch when it goes back in - hopefully next week. Figured I may as well service the whole system while things are easy to get to. Pulled the release cylinder off and cleaned it, looks pretty good. I'm wondering if I can get replacement seals for the internal piston, or maybe an entire new piston. Are these cylinders seviceable or are they replaced as an entire unit?

 

How is the fork going to move if the piston doesn't? LOL

Personally, I wouldn't waste my time rebuilding the slave cylinder, even if a kit was available. They are so cheap to buy the entire replacement, and so quick to swap out.

 

the diff in cost of getting the parts, and rebuilding it, to me is a moot point; I would just get a whole new one- master or slave clutch. the slave one should cost 20 to 30 bucks, depending on make , etc. Just make sure you get either the oem part, or Japanese or German part, NOT CHINESE!!!

 

so i put a 89 transmission (it was too a v6) on my 93 T4R sr5 v6. and i put my new slave cylinder on and i bled it and i start my truck up and i cant even shift into first gear or second nor into any gear. I put my fork and throw out bearing on right i made sure by looking it on YT and also its a newer clutch. So upon this mystery i even went out to buy a master cylinder and rebled the line and still the same thing i cant shift into first gear or any gear

 

Less than 2 years ago I had a reputable mechanic replace my clutch and the kit came with a slave cylinder. He gave me all the old parts so I know the slave was replaced. I also know that my slave cylinder is internal and not external.

Now for the following year after he replaced it I needed to have my system bled about every 4 months. And now finally, bleeding the system just doesn't work.

Do I have an air pocket possibly?

Or is my Clutch Master Cylinder bad?

Any way to check this?

I would greatly appreciate the best advice possible because I already ordered a new Clutch Master Cylinder!