O4 GM 2500 hydraulic slave
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O4 GM 2500 hydraulic slave I recently did an LS swap. I have an 04 6.0 out of a gm 2500. I have a NV4500. Both stock and bolt up as intended. I bought a stock clutch and flywheel kit and a stock hydraulic slave. I have completely bled the system, there is no air in it. My problem isn't travel to release the clutch, it's taking my foot off of the pedal and the slave not fully returning home. I posted this in another forum and they seemed to think it was a bleed problem or bad master. I defended the brand new master as the bore is correct and it's building pressure, enough to release the clutch as intended and the bleed, as it's not the issue at all for returning to the home position. I can push in the clutch and smoothly shift into all of the gears.
My issue. When I take my foot off the pedal, my clutch is slipping. Like the pedal is still pressed in a bit and the slave is not fully decompressing. The master has full travel and the pedal has full travel. When looking into the bell, I can see the slave extend and press the pressure plate cleanly. When I release the pedal, I can see the slave travel back to the transmission as it should. The only thing I can think of, is the slave is wrong? It seems to seat back to the transmission as it should, but still slipping. Slipping as in, if I put it in first and release the pedal it will creep forward, and when I give it gas, it will stop and just rev, like it's in neutral. I even looked into see if the slave had fully compressed and released the bleeder, to see if it would travel further, and it does not. Seems to be all the way back with the pedal released.
To answer questions ahead of time.
The NV4500 is freshly rebuilt and stock.
The 6.0 is freshly rebuilt and stock.
Bell is a genuine GM.
Brand new clutch kit and flywheel.
Brand new slave and master, with new line.
No shims. It's oem for an 04 2500 and not universal. Plus shims would make my situation worse.
It has been vacuum bled and pedal bled to assure of no air in the lines. But air would be clutch release issues and not at slave release with my issue.
I have asked "experts", friends, parts store geniuses, and in the GM forums. Everyone says "Not bled" or throw parts at it. I wish they would read before replying. I am trying here to see if any one has had this issue or have knowledge about it. Thank you for any input. This has stumped me for days.
My issue. When I take my foot off the pedal, my clutch is slipping. Like the pedal is still pressed in a bit and the slave is not fully decompressing. The master has full travel and the pedal has full travel. When looking into the bell, I can see the slave extend and press the pressure plate cleanly. When I release the pedal, I can see the slave travel back to the transmission as it should. The only thing I can think of, is the slave is wrong? It seems to seat back to the transmission as it should, but still slipping. Slipping as in, if I put it in first and release the pedal it will creep forward, and when I give it gas, it will stop and just rev, like it's in neutral. I even looked into see if the slave had fully compressed and released the bleeder, to see if it would travel further, and it does not. Seems to be all the way back with the pedal released.
To answer questions ahead of time.
The NV4500 is freshly rebuilt and stock.
The 6.0 is freshly rebuilt and stock.
Bell is a genuine GM.
Brand new clutch kit and flywheel.
Brand new slave and master, with new line.
No shims. It's oem for an 04 2500 and not universal. Plus shims would make my situation worse.
It has been vacuum bled and pedal bled to assure of no air in the lines. But air would be clutch release issues and not at slave release with my issue.
I have asked "experts", friends, parts store geniuses, and in the GM forums. Everyone says "Not bled" or throw parts at it. I wish they would read before replying. I am trying here to see if any one has had this issue or have knowledge about it. Thank you for any input. This has stumped me for days.
Only way to know for sure is pull the trans back out and take measurements. However, it is not impossible to get a brand new bad pressure plate, so that is also a possibility.
Older TOB designs would hold a gap. The newer CSC designs run the bearing against the fingers. Before we tackle that, what is the bellhousing face minus PP finger height ? That should be greater than the (compressed) bearing face height away from the trans. face.
Yes, you don't like need shims, but did you establish a proper gap for starters? Your "stock" approach is good, but out of spec parts can lead to an interference dimension vs. a gap. Too thick flywheel or disc, bad PP, wrong slave body or bearing.
Some OEM slaves run a spring that lightly hold the bearing on the PP fingers. This may work against you, but should be soft enough not to be an issue, and be entirely secondary to other issues.
Besides the (negative) shim measuring, did your pedal have an over-center spring?
Yes, you don't like need shims, but did you establish a proper gap for starters? Your "stock" approach is good, but out of spec parts can lead to an interference dimension vs. a gap. Too thick flywheel or disc, bad PP, wrong slave body or bearing.
Some OEM slaves run a spring that lightly hold the bearing on the PP fingers. This may work against you, but should be soft enough not to be an issue, and be entirely secondary to other issues.
Besides the (negative) shim measuring, did your pedal have an over-center spring?