Clutch Slave Cylinder Failure (1990 K1500 Scottsdale 5.0L)?

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sirmacbain

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Driving over very rough train tracks last week my clutch pedal went to the floor and I couldn't shift. Immediately pulled into a parking lot. The master clutch fluid reservoir was full, fluid filled with black silt, so I assumed the internals on the slave blew out. I waited for a tow, tow truck showed up and blew a hyro line. I got back in my truck and was able to shift into first, drove the truck home (a mile away) at home it resumed the peddle pushing to the floor without engaging.

I went to O'Reilly auto and bought their slave cylinder, replaced it, bleed it, and the truck was back on the road fine. I checked the reservoir and no fluid loss after a few days. That brand had only 1 review with 1 star for a brake master that failed the first week. Well, driving over the same tracks the clutch pedal went to the floor (and didn't return last time it was merely spongy); by the time I was able to pull over (pumping the pedal more than a few times in frustartion) the fluid reservoir was empty. I looked under the truck and the clutch line from where it passes the block to the slave was dry, the bleeder valve was dry, the clutch line and fitting entering the slave was dry, there appeared to be clear/brake fluid on the tranny where the slave inserts as well as potentially on the oil pan. I also checked the line from the master to where it passes behind the block and didn't see any fluid (nor any on the wheel well inside fender).


Presumably, I just got a bad slave cylinder that blew out when I shifted going over the tracks. Unless, the line blew out well above the slave and somehow the fluid leaked in some bizarre way. I'm ordering the "excedy" part from rockauto but now I'm paranoid that I need to order the nicer "luk" part that summit stocks.

Any advice on this situation? Am I fine with the exceedy or should I order the luk? Should I not be shifting while going over bumps (seems pretty crazy not to be able to but I also don't wanna beat the truck into the ground)?
 

Erik the Awful

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I always replace the master, slave, and any rubber hoses as a set. I've never seen one fail without the others failing soon after. I'd say buy the set that has the master, slave, and line already assembled and bled, but RockAuto doesn't show that as an option.
 

sirmacbain

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It was the old clutch line, good reminder to replace all recommended parts when doing job (still didn't replace the master cylinder). Likely that when I did the job it moved the line for the final damage rubbing on the body panel in the engine bay (but I'm guessing the damage was chronic as there's no way it was cut in 2-3 days of driving 5 miles a day).

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sirmacbain

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I always replace the master, slave, and any rubber hoses as a set. I've never seen one fail without the others failing soon after. I'd say buy the set that has the master, slave, and line already assembled and bled, but RockAuto doesn't show that as an option.

Yeah, I picked up a braided clutch line from AutoZone locally so I didn't have to wait a week for RockAuto to ship the hybrid hose/steel line. That did the trick. Of course, it failed behind the engine block where I couldn't see it.

Was lazy and didn't wanna pull the HVAC ducts to replace the master - should have just done that too, now I know better! Hopefully the master doesn't fail for a few years.
 

Robsez65

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I went to O'Reilly auto and bought their slave cylinder, replaced it, bleed it, and the truck was back on the road fine.
Ive have to replace mine several times. I got a year out of the last one but have had to replace it around 3 to 6 months. Just a bad run I guess (3 of them) . Glad its an external slave unlike my ex 91 F150 5.0 5sp.....I do buy their best available and generally have to go to their hub store for my parts anyway (it's close)..... Also had my line blow in about the same place too! The green guys had that for $75 and was able to also pick it up at their hub store that day as it blew close by there...lol...

90 GMC 5.7 get-a-rag 3500 5spd....daily driver..
 
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