Can’t fully push in clutch pedal all of a sudden

[rreegg]

Started up the truck this morning without issue. Let truck warm up for 10 mins at idle. Clutch must have been working fine initially to get trans into neutral. Went to leave for work and all of a sudden clutch pedal won’t press in fully. It’s feels like two similarly poled magnets pressing against each other - just bounces back after pressing. Can get the pedal to press inonly about half way. It feels like the pedal stops pushing right before the clutch is about to engage.

Viewed pedal assembly and no obvious obstructions. Heim joint looks good and I can see the master cylinder rod moving fine with pedal actuations.
Viewed master cylinder reservoir and it is full. No signs of fluid leakage anywhere - under vehicle or around any clutch components.

I swapped in a new pedal bracket assembly about 10 months ago with new plastic bushings and lubricant. It’s been working really well and has felt good.

Any other ideas of where to look? All I can think of is to start with bleeding the clutch master/slave cylinders and hope for the best. And continue looking for any obstructions.

Did a quick search for this issue and didn’t really turn up much. Do not believe the issue is related to firewall/master cyl push rod/pedal assembly.

Air temp was 37* this morning so doubt it’s anything cold related.. like freezing etc.

thank you for any ideas!

 

[rreegg]

I’ll check out the clutch fork too since that’s mention in Nero’s thread here. Just wasn’t sure where to look

Clutch pedal return

Good morning everyone, looks like I could use a little help on this, my two brain cells bouncing off each other this morning are struggling. Yesterday morning I started having issues with my clutch disengaging. Had to push it hard to the floor. Last night I replaced the master cylinder...

www.oilburners.net

 

[ihc1470]

I wonder if the compensator port in the master cylinder is blocked. How much free play do you have a the pedal before the rod into the master cylinder starts to move. Might try cracking the bleeder and see if you get full travel for a stroke or two. Probably not the issue but something not often checked either.

 

[Clb]

Revisit the last thing you did first, then backtrack.
If the pedal isn't the culprit, and the external fork looks good, try and see inside of the bellhousing ..
Godspeed
And easy fixes

 

[rreegg]

literally last thing I was doing before parking last night was driving around thinking “wow the clutch is really working good hope nothing happens to it”. Ha ha!

 

[Clb]

Last operation/repair is allways suspicious

 

[Cant Write]

I think your transfer case has convinced your trans to join in on the revolt!

I’d be Leary of their plans tonight when they bum rush the engine and force it to join the resiliency.

Best to sleep under your pickup with one eye open.

And keep that TDI parked outta earshot. Cause I’m sure that T-case has been dropping mien kampf ideology to any of your mechanical items that will listen.

Can never trust those transfer cases, spineless devils that spin both ways

 

[Cant Write]

Oh, sorry I can’t help!!! Best of luck!

 

[THSIM9]

I had a similar issue years ago. I actually got “stranded” for a minute because the slave cylinder failed. The line from the master to the slave actually popped off from so much pressure with nowhere to go. I had to start the truck in gear and rev match my shifts all the way home. Replacing the slave fixed my issue, but I’m not sure what caused it to fail in the first place.

 

[tvrrproto48]

I had the same thing happen on my 77 Kenworth. It may apply to smaller trucks. When the shop dropped the tranny they found several of the fingers on the pressure plate had cracked. The remaining fingers were flexing and there wasn't enough of them to overcome the springs.

 

[rreegg]

Finally sprung for a borescope inspection cam which will hopefully be useful for a lot of stuff. It hasn’t really been useful so far for any clutch diagnostics. But it has confirmed the pressure plate is there.. haha. Haven’t taken off the flywheel cover yet. Was trying to find a pre filled clutch/slave kit but the person at Oreilly said they’re not sold anymore. Really don’t want to fiddlefuck bleeding the clutch but it’ll probably be a necessity.

Truck is parked at my gf’s house so at least it’s somewhat convenient but don’t have any tools there.

Finally have some time to do some diagnostics. Gonna unhook the heim joint to isolate the clutch components and work in from there. Don’t think the pedal assy is hung up at all.

the tdi started leaking coolant from the hoses and threw a high temp warning light yesterday - the hose clamps just backed off so got that all fixed up. Dang when it rains it pours though.

Hopefully, at worst, it’s just an issue between the master/slave cylinders and those are in stock items at Orales.
Thanks for the comments it really helps with potential troubleshooting. Truck is importsnt for work even though I can get by in the vw

 

[Old Goat]

I had the same thing happen on my 77 Kenworth. It may apply to smaller trucks. When the shop dropped the tranny they found several of the fingers on the pressure plate had cracked. The remaining fingers were flexing and there wasn't enough of them to overcome the springs.

I had that same thing happen to my 82 Datsun King Cab 5-spd.
One morning jump in the PU to start it, and Clutch wouldn`t push in. Like pushing on a rock. Worked fine day before when driving it.

Pulled Engine and Trans., separated them and ****** out the Clutch assy. One of the Diaphram spring fingers broke off and jambed into something else. never seen that before or since.
When Iam at a red Light, heavy more stop than go traffic. Foot is off the Clutch and in neutral. So it wasn`t from abuse.

EDIT: Ya gotta be kidding me, J E R K ED is another dirty word.


Goat

 

[rreegg]

I really try to baby the clutch too and stay in neutral whenever possible.

Separated the heim joint and pedal assy works fine in isolation.

Removed the flywheel cover ajar and from what is visible there is nothing wrong with the clutch internals - no broken parts to the diaphragm spring/fingers. But can only really view the bottom half.

Is it possible to test the clutch internals in isolation? It’s very difficult to move the clutch fork by hand and don’t expect to be able to.

Will try bleeding the clutch master tomorrow. Already picked up new master/slave cyclindera if it comes to that but would like to eliminate the clutch internals from potential issues.

I figure it’d be worth checking how things feel after disconnecting the slave cylinder from fork but at that point it may be easier to just replace the slave

 

[IDIBRONCO]

When Iam at a red Light, heavy more stop than go traffic. Foot is off the Clutch and in neutral.

I do the same thing. I'll wait until I see the light for the other direction turn yellow before I push in the clutch and put it back in gear again. Sometimes, I'll even coast up to a stop sign in neutral. Maybe that's part of why I've used the same clutch parts in three different vehicles since early 2006.

 

[rreegg]

Dang. Popped off the slave cyl and can move the clutch pedal freely after. Must be an issue with clutch internals. Wonder if seized TOB or something. Not really able to view everything in there but looks like I’m hosed for the time being.