78/87vettes

Last night my stepson and I embarked on what we thought was going to be a simple job - replace clutch and master/slave cylinder on his 1987 3/4 ton chev truck. We installed all new components but no matter how long we tried could not get the pedal to pump up - now this is a simple system - lot easier than our C3 brake system which I've managed to figure out thru lots of good forum help, so I'm reaching out again. Does anybody have any ideas or lessons learned on this problem? We bench bled the master cylinder before installing it and it would hold pressure.

six-T-six

I had a similar experience but it was a 94 Explorer. Simple job was supposed to take an hour ended up taking a loooong time. Hopefully, there will be some similarities that will help! Symptom: I bled the crap out of the system and the clutch pedal still went to the floor. :smash: :smash:

Here's how I finally got all the air out. On the Ford you bleed it at the slave cylinder. There is a quick connector that lets you connect the tube from the master cylinder to the slave cylinder. I got an extra connector and popped it onto the tube and ran a short length of tubing from it into a jar of brake fluid and bled the master cylinder. When I removed the quick connector, the valve on the tube side prevented air from re-entering the system and I connected it back to the slave cylinder. All the air was trapped in the long curvy tube from the master cylinder....I couldn't believe after all the time I bled it from before there was still air in it. :crazy:

78/87vettes

Thanks six-t-six - your right about the similarities; my son looked in a Motors manual for help and it said to unbolt the slave cylinder and hold it up at a 45 degree angle and bleed it that way. He did and it bled the first time with great results. I don't know exactly why that works but I suspect this allows trapped air to escape.