Installation of Stock or McLeod Clutch Master and Slave Cylinder

Since the stock slave cylinder had 90K miles on it, and the McLeod clutch needs the slave to be in good working order, I decided to replace it. GM now makes a nice replacement kit if you need to replace anything with your clutch hydraulic system, you just replace everything. It comes complete from reservoir to master to slave _Filled_ with fluid so you don't even have to worry about bleeding the system after installation. It's GM 12559912. If you look at the bottom picture and substitute the black master cylinder in the picture for the silver McLeod master that's the complete kit. However I needed to replace the stock master with the McLeod adjustable master cylinder (139001).

1. To remove the clutch hydraulic system start with the clutch pedal. There is a C-clip holding the master cylinder pushrod to the Clutch pedal. Remove that and disconnect the pushrod from the pedal.
2. Then also from inside the car, unbolt the 2 nuts (Yellow and Red arrow) holding the master cylinder to the firewall. You might expect the master cylinder to easily slip out into the engine bay, but there might be a very thin metal washer on the bottom master cylinder stud (Red Arrow) between the firewall and the metal bracket that will prevent that (I think GM used this during the install to make the install easier - but it makes removal more difficult). I was able to "unscrew" the washer off the stud using my fingernails. Now the master cylinder will slide into the engine bay.
3. Unbolt the slave cylinder from the bell housing.
4. Now disconnect the reservoir from its mount and fish the whole thing out of the engine bay. If you are replacing everything with the stock kit just reverse the process. Attach the slave leaving the plastic clips attached. They will snap when you first depress the clutch pedal.
5. Since I was replacing the stock master cylinder with the McLeod adjustable one I needed to do a couple extra things. This photo shows a comparison of the Stock (on left) with the McLeod Master Cylinder (on right). The McLeod has a thicker pushrod and the end is adjustable.
6. This shows detail of the stock (on left) and McLeod (on right) master cylinder (and new stock slave far right). The braided hose is held in place by a pin that you drive out with a punch (I cut the point off an appropriately sized nail and used that as a punch) and drive back in to hold the hose in place. So I knocked out the pin from the new stock master and moved the hose to the McLeod master and put the pin back in. Click on the photo to see a larger image with the pin location shown.
7. This shows the McLeod connected to the reservoir and slave.
You will notice that the fitting from the master cylinder to the reservoir is a straight fitting. In my car this hit the brake booster. I replaced this fitting with a 90 degree one, (not shown in these pictures) pointed between 12 o'clock and the upper right u-bolt hole. That gave the needed clearance to install the master on the firewall.
8. Before attaching the slave to the bellhousing I pushed the plunger in several times to bleed any air out. Once I stopped seeing air bubbles the bleeding is complete. Attach the slave leaving the plastic clips attached. They will snap when you first depress the clutch pedal.

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