Clutch Master/Slave Cylinder Options

[Idle Serge]

I apologize in advance for beating a dead horse here - I've been searching the forum/web for a few days now and am unable to find what I am looking for.

Issue/Problem - my clutch pedal feels "odd". Very short, very soft and it seems like it has a "secondary push" once you hit the 1st "bottom". I'm unsure how else to explain it...when engaging the clutch, it bottoms out easy but won't go into gear unless you give it another "thrust" and continues to sink another 1/2 inch, at which point, the gears will go in smoothly. However, you go too far (perhaps the last 1/4" to the floor) and it will not go into gear.

Current Setup - 94' C1500, LM7 5.3L and NV3500 w/external salve cylinder.

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20220510_173302 by Sergio Zapien, on Flickr

Clutch Master/Slave Cylinder - Duralast Clutch Slave Cylinder PFHK064 (this is actually my 3rd one as the pervious 2 have failed: one started leaking at the reservoir while the 2nd one just seemed to quick internally). It's an all in one system, pre bleed and just install and go. Upon further investigation, is does have a bleeder screw and we've actually tried bleeding it but it didn't help.
For Reference: https://www.autozone.com/drivetrain...last-clutch-slave-cylinder-pfhk064/274730_0_0

Here's the most recent parts list for the clutch job last weekend:

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Screenshot_20220329-133818_Email by Sergio Zapien, on Flickr


Upon taking out the old clutch/fly, it showed very little signs of wear and/or usage. The only thing we noticed that may have been a cause for concern was the throwout bearing:

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20220509_175145 by Sergio Zapien, on Flickr

Regardless of the condition of the old setup, everything new went in but my problem with the weird clutch pedal engagement was still present. Syncromesh was used to fill up the NV3500.

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20220328_122652 by Sergio Zapien, on Flickr

I'm a bit lost here but I'm essentially seeking advice on how to combat this issue - I'm open to suggestions/advice/upgrades/etc such as a Wilwood custom setup or anything of that nature. As long it properly functions, I'm all ears. Even if I have to utilize one of those aftermarket pedals they sell for hot rods.

I look forward to hearing from some of the gurus and anyone willing to help me out here - thanks again, GMT400!

-Serge

 

[DeCaff2007]

It sounds to me like you still have air in the line between the clutch master and slave cylinders. Think about it this way: If your brake pedal was doing that, you likely have air in the line or one of the calipers is bad (and by bad I mean leaking).

 

[GoToGuy]

Are you using standard OE type parts? Pressure plate type? Borg beck, diaphram ? Pilot bearing ok? Diaphram pressure plate uses throwout bearing with rounded raised face like doughnut. Three arm lever pressure plate uses other style.
It may be ready to install, but I would still bleed, bleed, bleed till absolutely, bet my life it's good. If it's hanging up just little it will never shift correctly.

 

[Erik the Awful]

It sounds to me like you still have air in the line between the clutch master and slave cylinders.

That's what I was thinking, until I saw the differences in the throwout bearing. I think that's your problem. What model did you use to get those part numbers? Not that I can help from there, but if someone else has done an LS swap they might be able to see what's up.

 

[Idle Serge]

It sounds to me like you still have air in the line between the clutch master and slave cylinders. Think about it this way: If your brake pedal was doing that, you likely have air in the line or one of the calipers is bad (and by bad I mean leaking).

There's no noticeable leakage in sight - I was always under the impression, that if air was present, it was more of a spongy feeling and repetitive pumping was required to get it to go into gear. That is not the case here but I wouldn't hurt to give it another bleeding just to be sure.

I get your reference though - unfortunately, this is slightly different, since it takes a fair amount of force to get it to go over that initial "bottom/stoppage". Unlike a spongy brake pedal when it is either leaking and/or air in the line.

Are you using standard OE type parts? Pressure plate type? Borg beck, diaphram ? Pilot bearing ok? Diaphram pressure plate uses throwout bearing with rounded raised face like doughnut. Three arm lever pressure plate uses other style.
It may be ready to install, but I would still bleed, bleed, bleed till absolutely, bet my life it's good. If it's hanging up just little it will never shift correctly.

All OE stuff as listed above - everything is new with the exception of the fork. Otherwise, all new from the pilot bearing to the throwout bearing and everything in between.

Hence the reason I am open to an aftermarket setup since bleeding is an absolute pain on these OE setups - I've never had to pump a slave to much to get it going unlike on any other type I've done in the past.

That's what I was thinking, until I saw the differences in the throwout bearing. I think that's your problem. What model did you use to get those part numbers? Not that I can help from there, but if someone else has done an LS swap they might be able to see what's up.

It's a well known list in the LS swap community and everywhere I looked, the 1377C was always highlighted. Keep in mind, before I opted to do this clutch job, (after about 2 years of use in my ownership) getting it into gear was getting really tough; no grinds but I would have to really force them in and pumping the slave didn't do any difference. Regardless, the "old" clutch and fly where in great shape! So I figured the extended 1377C throwout bearing which makes up for the crank depth difference, was the main cause of my problems. That, however; doesn't seem to be the case, though after getting past that initial "stoppage" point, it'll shift in fairly smooth.


Thanks for chiming in thus far! It's greatly appreciated y'all.

 

[Idle Serge]

How about the Manual transmission folks in general - what master clutch/slave cylinder are y'all using? Any relevant insight is greatly apricated.

 

[Idle Serge]

Been prowlin' the interWebz in search for some answers. Someone at LS1 forums suggested getting in touch with Tick Performance - I was able to get in touch with someone over there who recommended the following:

https://www.tickperformance.com/adj...8-02-camaro-firebird-ls1/#product-description

Upon watching the installation video, it looks like it'll take a fair amount of work to get it to work on the GMT400s since the F-Body master is installed at a slant and not straight like our OE setup. I did like the features/build quality of it tho - I wish we had a direct setup for our application.

I did come across some universal setups that I may give a try, depending on being able to source the correct braided SS line that would mate up to an off the shelf slave cylinder:

Tilton UNIVERSAL KIT, MASTER CYLINDER, COMPACT, 3/4"

Late model performance specialists, offering parts at competitive prices, LS1 LS2 LS3 LS6 LS7 LS9 LSX

www.tickperformance.com

Tilton UNIVERSAL KIT, MASTER CYLINDER, 3/4" DIA

Late model performance specialists, offering parts at competitive prices, LS1 LS2 LS3 LS6 LS7 LS9 LSX

www.tickperformance.com

I did also find this Slave Cylinder that is made out of aluminum vs most of the plastic ones on the market - I'm just unsure what kind of insert it has to accommodate for the clutch line:

More Information for PERFECTION CLUTCH 360027

Perfection also has a braided clutchline already made but it out of stock :/

Perfection Hy-Test Online Parts Catalog

ShowMeTheParts is changing how the world finds replacement parts for their vehicles.

showmetheparts.com

Wilwood recommended their 3/4 master but hasn't clarified if i can purchase a line and threaded adjustable rod to connect to the factor pedal:

Wilwood Disc Brakes

MasterCylinder No: 260-15098, master cylinders, aluminum tandem, combination remote, compact master cylinder, go-kart master cylinder, handle-bar master cylinder, rebuild kits, high volume, hvm master cylinder, tandem, bleeding kits

www.wilwood.com

I also checked out Wilwoods clutch pedal combos but it looks like getting the OEM pedal off is a bit of a pain lol

Wilwood Disc Brakes

disc brakes, big brakes, bbk, brake conversion kit, bolt on brake kits, calipers, pads, pedal assembly, rotors, dynalite, dynapro, hats, hubs, line kits, master cylinders, pads, polymatrix, racing, hats, brake lines, superlite, d52

www.wilwood.com

That's about where I am at - waiting to hear back from Tick about using one of the universal ones they have listed, along with their speed bleeder clutch line and see what it takes to get it hooked up to a factory slave.

Wish me luck!

 

[wb292]

Make sure when you bleed at the slave that you raise the front of the truck ONLY. If you look at the slave, the bleeder IS NOT the highest point. You have the raise the front of the truck to get the small amount of left over air to come out of the bleeder. Otherwise fluid will come out and it looks like all air is gone but it's not. The slave should just sit at a different position with the different size throw out bearing. Because the clutch fingers is what returns the throw out bearing when you release the pedal.

 

[Idle Serge]

For whatever it is worth - it was the fork. Some hardware was actually missing entirely. There are still some concerns with the clutch master cylinder as it is SUPER soft but it is operating. I'll continue to explore clutch line options and such to improve engagement in the future. That is all.

 

[turbskiiis]

For whatever it is worth - it was the fork. Some hardware was actually missing entirely. There are still some concerns with the clutch master cylinder as it is SUPER soft but it is operating. I'll continue to explore clutch line options and such to improve engagement in the future. That is all.

Did you ever get the pedal issues resolved? I am considering getting the universal to at least have some mingle room. I am going from a 2004 interval slave and I am honestly not sure how the medal and master situation is going to go lmak