Bleeding clutch master cylinder

[wylde8]

Just replaced the clutch assembly and slave cylinder on my 97 Ranger 4.0. Really the only thing left to do at this point is to bench bleed the clutch hydraulic system so I can reinstall it. I thought I had done my homework beforehand and looked into how to best do this. Everything says to remove the reservoir, clutch master cylinder, and lines, hang them up with the master cylinder pointed upwards, and bleed the system. However, when I add the brake fluid to the reservoir, the fluid just drips out of the slave cylinder connector. If I push on the pushrod of the clutch master cylinder, the fluid shoots out the bottom and empties almost immediately. What am I missing? Everything I read about the procedure said no fluid should drip out of the slave cylinder connection and bubbles should slowly release into the reservoir.

 

[mogster]

Is there some dirt or debris in the fitting, if not then you can order the lower hose with the fitting from Napa.

 

[wylde8]

Sorry, let me clarify. I'm talking about the fluid coming out at the very bottom of the hydraulic assembly where the slave cylinder connection is. The connector I'm referring to is the one that plugs into the slave cylinder/throwout bearing, not the one where the plastic line connects to the clutch master cylinder. The whole assembly is pretty much impossible to bleed if the fluid dumps out almost as fast as I can pour it in.

 

[adsm08]

There is a little rubber o-ring on the line fitting. If it is torn it can do exactly what you are describing.

 

[wylde8]

The o-ring is not coming into play yet. I have the reservoir, clutch master cylinder, and hydraulic line hanging in my basement. The hydraulic line connector that would normally hook into the slave cylinder, which is where the o-ring goes, is not connected to anything yet. I pour brake fluid into the reservoir, it runs through the connector tube past the master cylinder, on down through the hydraulic line, and out the fitting at the bottom.

 

[FritzTKatt]

Then the fitting is bad. Replace the line (doubt the home mech has the tools for a new fitting, and the line may be too short) wouldn't hurt to save yourself some trouble down the road from the dry rotted line.

 

[Earl43P]

It's supposed to be a quick disconnect fitting that doesn't allow flow until connected to the slave fitting. See if you can pop it back closed or else you need a new line (with that fitting).

 

[wylde8]

So its a check valve fitting! That would make sense. Thanks for the replies everyone. I'll take another look at it tonight after I get off work to see if the check valve is just stuck open or if its faulty.

 

[Earl43P]

I wouldn't call it a check valve, more like a poppet valve.
When the two fittings are mated, a plunger on one end holds the valve open so fluid can flow. When disconnected, a spring pressure forces the valve closed, arguably so that you can replace the slave without having to bleed.

A check valve prevents fluid from flowing backward, that is not the case here. Fluid flows both ways.

 

[PlumCrazy]

Its a "checked" disconnect. Atleast thats what we call them in the hydraulics industry....

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