Just on a side note, I noticed my 95 F250 with the ZF5 was starting to have problems going into reverse and the pedal was feeling kind of low, I figured the Slave was going out, I checked the fluid level and found it to be full, but the fluid was also inside the rubber cup, Checking the edges of the cup I found a tear in the lip. I located a new cup on EBay after trying to repair the old one with no luck, as soon as I installed it and topped off the fluid, It acted like a brand new clutch.

 

I appreciate the vote of confidence, you guys on here have saved my truck (any in turn, my business) more than once.

Truck has been fine since my last post, nothing acting up except for that weird split second rattle when I start the engine, coming from the trans. area.

However, today I hooked the trailer back up and the problem came back. I was just moving the trailer from the front to the back of my shop, and the no-shift issue came back just like last time when I first noticed it, which was when I was moving the trailer.

Two things to note, first, it seemed that if I pumped the clutch 5 or 6 times, it would go into gear when I tried it again. Not too smoothly, but it would go. No grinding or anything but it just didnt feel as smooth as normal. Also, it seemed that as I pumped the clutch those 5 or 6 times, the weight of the clutch became greater. What I mean is, before pushing the clutch in 5 times, the clutch felt lighter than normal and wasn't pushing back as strongly, until I would pump it and it felt like it gradually went back to normal as I pumped it.

Second thing, just like Lead Head mentioned, I turned the truck off when the problem came about and boom, right into gear, no problems. Turned the truck back on and it wouldn't go into gear, and just to check- turned it back off and it went right into all the gears. Like mentioned, this points to a clutch issue, NOT a transmission issue, correct?

If someone could please elaborate on my next steps or just the specifics of what this could be, that would be great.

Thank you.

 

Your pumping the pedal 5 or 6 times says you have a slave cylinder issue...you may not be leaking but it sounds like you're getting air. Did you check the cup in the reservoir for cut or holes? You may just need to replace the slave but as long as you have to pull the trans you may as well replce it all and be done with it.

 

Mike1, apologies, I never saw your message from 2 weeks ago about the rubber cup. I just checked it and didn't notice anything, no holes or tears. I was kind of hoping I would find something.

I need to read up on my clutch and transmission details so I can understand what the actual problem is. I only have a very faint understanding of what the slave's function is.

Two things: First, just like last time, this problem came about when I was squeezing my trailer into its spot. Because I am not very good at backing up with that thing, it was a lot of forward and reverse over and over, while riding the clutch so the truck would only inch forward or back a small amount. After a minute or two of this is when the problem happened. I don't know if this is worth noting or not, or could directly point to slave or clutch, just thought I would mention it.

Second, you mentioned it could very well just need a slave replacement, but said I may as well just replace it all and be done with it. I agree with you on this, definitely the smarter move. However, with my faint understanding of the different clutch and transmission components, do you mind telling me what you mean by "replace it all". Are you just talking about the slave and the clutch, or are you saying to replace the whole transmission and its components, and the clutch and slave?

Just want to be clear before I break out the tool box. Thanks for the help.

 

Seems like your trans shifts fine when shutting engine off. So this is what I'd do, drain the trans fluid drop the trans, remove whole clutch assembly, including slave. Either resurface or replace the flywheel. Install new clutch assembly including slave. If you want to take trans to a qualified shop and have them go though it, that's totally up to you.

 

Your problem could be either the slave cylinder, or the master cylinder. The slave cylinder is what pushes the clutch springs to disengage it, while the master cylinder is the one attached to the clutch pedal.

Usually the slaves fail first, because they're in a much harsher environment. The master cylinder is however far easier to replace.

Before condemning either, a somewhat common problem is the firewall cracking near the clutch master cylinder. Have a friend push the clutch pedal in and out, and look for bending/flexing of the firewall from under hood near the pedal assembly.

 

Lead head thanks i completely forgot about firewall flex, that is absolutely one of the first things to check.

 

Mike1, The things you said you would do help out a lot, Now I am able to start seeing what is really necessary and getting the confidence to give it a wing.

Lead Head, I actually had to replace the master cylinder about a year ago because of a broken clutch pedal piston, so either I didn't install it correctly and the problem is just showing now, or it points to the slave. I may not have installed it correctly or another problem has come up, but I am leaning towards the slave. Is there a way to be 100% sure it is NOT the master?

I checked for the firewall crack, good tip. I didn't see anything out of the ordinary while having someone pump the clutch. The master would move VERY slightly (like 1/16 of an inch if that), but I don't think that is the issue.

I talked to a friend of a friend who has serviced my same truck before. I told him one thing that made him immediately think it is the slave: I thought it was normal, but my clutch needs to be pressed all of the way to the floor in order to engage it and change gears. I thought this was just the way my truck's clutch worked, but he said no you should just be able to push it in a couple inches and it will engage the clutch. This is not the case with my clutch, the first 2-3 inches or so when pressing the clutch pedal don't do anything, there is just a slight spring feeling pushing back, once I get the clutch about half way pressed it starts to function and will fully function when pushing the pedal all of the way to the floor. Apologies that I left this part out, I didn't know that it was out of the ordinary.

The friend said he is almost certain it is the slave, like you guys said, OR if I am lucky, I just need to bleed the clutch line because there could be a little air inside. And just to be clear, to bleed it I need to have someone pump the clutch a LOT of times and then hold it pressed down, then crack the seal by the slave, right? I hope this is my issue, if not I will be ordering the parts.

Thanks, looking forward to seeing what you guys think.

 

Generally to bleed the clutch, you just need to open the bleeder, have someone firmly press and hold the clutch pedal to the floor, close the bleeder, and then release the clutch pedal. Do that a few times until no air comes through.

 

Just remember the reservoir is really small so one or two bleeds and you'll need to fill it again, DONT let it suck air. Good Luck and keep us posted.

 

Finally got around to bleeding the clutch, tough to find someone willing to sit there and pump the clutch for me over and over.

Bled it a couple times and didn't notice any air, all fluid, so that seems alright.

One thing I did notice is that the the plastic bushing where the clutch pedal metal pin connects to the piston on the master was worn out and not aligned properly, not sure how it stayed on there. I messed with it a bit and the clutch feels a lot better now. Only have to push it in about half way for it to function, which is great.

As for the original problem, looking now for the parts needed. Slave Cylinder, Clutch Set, release bearing, flywheel (if you think that is necessary?).

One thing I can't figure out is if I have a 10" clutch or an 11" clutch. I have searched everywhere and can't seem to figure it out. Any ideas?

Thanks everyone

 

It's generally a good idea to resurface the flywheel, but it's not 100% necessary.

 

Well, like what was mentioned before, if I am going drop out the trans and replace the clutch, I may as well just replace everything. I found Flywheels for around $100, I feel like a resurfacing would be similar in price.

It is probably the original flywheel in my truck, so a fresh one wouldn't hurt, but with the parts adding up, wasn't sure if the flywheel was a necessary replacement. If it is a good idea, I should do it.

Any clue on clutch size? I think 10", but just want to be sure.

Thanks, Lead Head.

 

Don't have a clue on the clutch size, sorry. Generally the flywheel/clutch/pressure plate should all match. So I don't think it particularly matters as long as you get the 11" flywheel for the 11" clutch, or the 10" flywheel for the 10" clutch.

 

No problem at all. I will check that out. Thanks