1997 350/5 speed clutch line problems.

[Dthreat]

So I replaced the master cylinder with oe replacement. Replaced the slave/throw out with Dorman replacement. All new. I did not change the line between the two. After the master and slave I got ok pedal but not awesome. Had a couple inches of sponge before it firmed up. I don't know how many times I bled the damn thing. Slam, pump and gravity methods. It was workable for a while. But not long ago when we started driving out further everyday I'd notice after a 40 mile stretch in 5th gear I'd loose pedal. I could pump it back up in three or four pumps and it would he fine the rest of the way in. No fluid loss but when I went to bleed it again it had air in it. Ill probably replace the line with the residual valve thingy on it because that's the last thing to replace. I just wanted to find out from you guys if im missing something or if it's most likely a tiny leak in the line somewhere.

Thanks guys.

 

[RichLo]

sounds like a faulty master. can you return it under warranty?

 

[Dthreat]

Possibly. I got it off of Amazon. Its also a Dorman. I'd bet I can just tell them its not working and they'll send me another one. My wife is pretty good at that with Amazon.

Thanks

 

[Erik the Awful]

I haven't had the pleasure of bleeding a GMT400 clutch setup yet, but everyone who talks about it reports that it's a pain in the butt. I have an NV3500 in the shop, and I bought the pre-bled and assembled kit for it. I was taught to replace the master and slave cylinders at the same time, and I've had the hose go bad before, so buying the kit is a no-brainer.

 

[Dthreat]

Its my first experience with them and I gotta say I hate the design. The floating fittings just don't make sense to me. I know they work but damn. The fitting under the master will swivel, the fitting going into the slave wiggles and spins and I'm told its supposed to be that way and that the pressure of the system keeps it all sealed up. I'm old school. Give me some threads and hydraulic swivel fitting.

 

[Postmech]

My 1986 C10 has a 4.3 with 3 speed manual. I have had to replace both slave and master twice since truck was new. Best way I have found to bleed air out is to force fluid from slave cylinder upwards to master cylinder. I used a large syringe I got at Tractor Supply. I loosened bleeder screw on slave and used a piece of hose clamped on screw and syringe.Yes it leaks around threads. Any kind of pressurized fluid supply will work, such as an old power bleeder. First time was a SOB before I figured it out.

 

[Dthreat]

Damn that's a good idea. Ill try that first. I was going to pull the master out with the line and re bench bleed. I'm reading that there could be some air trapped in the master. I also saw a video of guys squishing the slave in and out to bleed Air all the way up to the master. we did not do this. So maybe your method will work. Ill keep y'all updated.

Thanks