clutch pressure problems

[4speedburb]

so ive replaced the slave cylinder, bled it, and drove it around town and its all fine, but the second i drive for more then 10 minutes on open road, i lose all pressure, i have no idea what is going on, maybe im not bleeding right, or somthing, but im lost as to what is going on

 

[towjoe]

i just went through this with my 2000 hd3500. the bellhousing bolts had broke off on 4 of them and it had one loose bolt on the clutch presure plate. the loose bolt on the presure plate made one finger on the diafram stick out almost a quarter of a inch further than the rest. we belive while driving it it would work the throwout bearing and slave cylinder back thus making too much travel to disengage the clutch when pedal was pushed. Mine worked great when cold but more it was driven less it worked. Had a brand new clutch, slave, and master on it 6 months ago when I bought truck. Works great now we tightened up bolt on presure plate and fixed bell bolts

 

[bucket]

Could still be air in the line somewhere. What method did you use to bleed it?

 

[4speedburb]

pumped pedal till there was pressure, and pumped it for like 5 mins, held down pedal, and popped the bleeder, tightened it back up, and did it over again, while checking fluid in the process

 

[bucket]

Try unbolting the slave, but leaving the line connected. Remove the reservoir cap. Hold the slave with the line inlet as the highest point, then push the rod all the way in a few times and slowly let it back out (a balled up rag will save the palm of your hand). This should force any trapped air bubbles up through the line and out the reservoir.

With any luck, you just have a little air stuck in there and no mechanical issues.

 

[smurph20]

Thats what i had to do with mine Bucket. Took several tries to get it right and get the clutch working right.

 

[4speedburb]

i got it all bled out, and im almost positive it is the master cylinder, the problems i was having was after bleeding the line, it lost all pressure, and wouldnt gain it back unless manually putting pressure on it, so on friday i will be replacing the master, whats the best way to go about doing that?