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1968 Dodge W200, Slant 6, 4-Speed

I came home one day and found that my clutch master cylinder had leaked out into the floor of my cab. I ordered a new master cylinder, installed it, and connected the linkage to the clutch pedal.

When going through the bleeding process, there were problems with the pedal not coming back to its original position after depressing it. At first I thought it had to do with either of the springs: the overcenter spring or the one at the slave cylinder. From what I saw in a few forum responses, it seems the spring on the slave cylinder is not a heavy duty spring and only

there to keep the release bearing out of contact with the clutch during normal operation.

The "over center" spring is there to help depress the clutch only. Yes, it helps the pedal pop up but only when its coming back up past center.

First, I replaced the return spring on the slave cylinder, which was a rusty mess and seemed to be too heavy duty for the application. I am not sure how massive of a spring is needed, but from what I saw in other forum searches, I wouldn't think it needed to be too heavy.

Then I adjusted the overcenter spring so that the pedal comes back, but it does so weakly. Adjusting the other way did not help with the pedal returning. So I don't believe that is the issue. I had started the truck, and attempted to shift the tranny with it the way it is, but it is difficult / almost impossible to put it in gear.

With my limited knowledge, I am not sure what exactly I need to do to correct this issue. Any help would be appreciated.

Jim

Did you bench bleed your new clutch master cylinder before installing it?
John

I did not. Just bled the system at the slave cylinder after installation. Did not even think of the bench bleeding.

Will try to bleed it while mounted on the firewall. Hopefully that will rectify the issue.

Thank you.

With the vast majority of hydraulic clutches, it is the spring action of the pressure plate that returns the pedal. If you look at the Dodge cars of the 60's, there is a massive return spring in the pedal assembly. Keep bleeding it, get all the air out of it and it should be fine. It is a single piston type, so in theory, just cracking the bleeder screw on the slave should get the air from the system. But you may have to have someone pump the system up and then crack the bleeder screw.

Be sure it is a clutch master (no RPV), not a brake master (with RPV). How do u know the slave is not also bad?
Been driving a 62 W300 since 1983. Rarely is it just one cylinder that needs replacing. Upgrading to stainless lined cylinders is a huge improvement.

I do not know the slave is also bad. All I know is that the master was the one that leaked all over the floor of my cab. I did purchase a replacement slave cylinder, but was not exactly sure how easy it would be, so I was holding off on it. It is also not the easiest thing to get to (I have an exhaust pipe limiting my access from below). Again I am not a mechanic, just trying to learn a little as I go. I think I need to replace the line that runs between the cylinders, as the nut near the master (not the one that threads directly into the master) is corroded and impossible to tighten with a wrench. Probably just gonna get it to a shop to replace the lines, as I was going to have the brake lines done anyways.

And I do not know what RPV stands for, something something valve I am guessing. I can probably google it... The clutch master cylinder I ordered online looks pretty much the same as the one I am replacing.

Thanks again for the responses.

residual pressure valve

Bucky