MyE28.com

While I actually did this on my e30, the part number for the master cylinder (MC) on my '87 535is is the same, and the methodology is identical.

First, I removed about 120cc of brake fluid, enough to get the reservoir level below the connector for the clutch fluid, then opened the clutch bleed screw and let it drain. While the draining was in progress, I remove the clutch fluid hose, the blue fabric covered hose, from the reservoir. I then removed the drivers seat to gain access to the MC in the car.

The process is kinda talked about rather thinly in the Bentley, so I winged it. I took the clutch line loose between the flexible hose and the rigid line that is attached to the MC. In the car I took the two MC bolts (10mm hex, 6mm shank) out and let the MC hang there while I went back under the car and loosened the rigid line where it attached to the MC, I did that so it could move around as necessary. Back in the car, I didconnected the MC from the clutch pedal bracket, and then I pulled the MC with the intent that it come out of the grommet it passes through. The grommet came out with it, the fluid supply hose came out of its grommet just fine, and out came the MC.

Installation is the reverse of the above, except make sure you install the MC grommet into the firewall BEFORE you put the MC through the grommet, it's a pain to get throught the firewall otherwise. I also had a new piece of fluid supply hose, about 2-3 feet of it, and that I cut to length AFTER I sent it through its grommet. That's to enable feeding it up to the reservoir with no trouble. Yes, putting the two 6mm bolts back into the MC is a tedious task, but it's got to be done, think about putting grease into your 10mm socket to hold the bolt while you put it in place.

Now, no fluid leaking out of the MC, and slightly more solid clutch disengagement.



[Edit by fastpat on [TIME]1108414211[/TIME]]

Good write up pat! its great to have a description of the pitfalls available in the archive. I did the same thing today, because my new billet aluminum MC was either broken when I put it in, or broke very shortly after installation. I ended up dissasembling and cleaning the old FAG cast metal MC, and putting it back in. I decided that the new master had to be broken after 3 or 4 different bleeding attempts, tightening and adjusting nuts and bolts, including the eccentric, and STILL having and inch and a half of complete slop! I opened it up to find that the ring retaining the ball into the socket of the piston was not holding the ball/rod in place.

So I am curious, how do you loosen the flare nut on the end of the MC while its still bolted into position? Maybe my flare wrench is too long, or I lack dexterity, as I cant get the nut turned far enough to get a second turn. What I did, which is probably unorthodoxed, was to disconnect the hard line from its connection to the flex line, and then wiggle and pull the detached MC until the hard line came into the passenger compartment.

Chris,
Also enjoying firm disengagement

[QUOTE="pdx 528e"]So I am curious, how do you loosen the flare nut on the end of the MC while its still bolted into position? Maybe my flare wrench is too long, or I lack dexterity, as I cant get the nut turned far enough to get a second turn. What I did, which is probably unorthodoxed, was to disconnect the hard line from its connection to the flex line, and then wiggle and pull the detached MC until the hard line came into the passenger compartment. [/QUOTE]

I did the opposite. I couldn't get at the thing inside the car but I could reach it outside. So I pushed the nose of the MC out through the firewall and unscrewed the fitting there. Either way, IMHO it is virtually impossible to unscrew this fitting with the cylinder in place. Break it loose while bolted in place and then move it to a more accessible location to disassemble.

[QUOTE="pdx 528e"]Good write up pat! its great to have a description of the pitfalls available in the archive. I did the same thing today, because my new billet aluminum MC was either broken when I put it in, or broke very shortly after installation. I ended up dissasembling and cleaning the old FAG cast metal MC, and putting it back in. I decided that the new master had to be broken after 3 or 4 different bleeding attempts, tightening and adjusting nuts and bolts, including the eccentric, and STILL having and inch and a half of complete slop! I opened it up to find that the ring retaining the ball into the socket of the piston was not holding the ball/rod in place.

So I am curious, how do you loosen the flare nut on the end of the MC while its still bolted into position? Maybe my flare wrench is too long, or I lack dexterity, as I cant get the nut turned far enough to get a second turn. What I did, which is probably unorthodoxed, was to disconnect the hard line from its connection to the flex line, and then wiggle and pull the detached MC until the hard line came into the passenger compartment.

Chris,
Also enjoying firm disengagement [/QUOTE]
Chris, I loosened, but did not remove, the flare fitting on the master cylinder, just so the line could turn. The 11mm open end wrench is a fairly short one, but not of the "stubby' length. I only needed to trun the flare nut about 1/2 to 3/4 turn to get it loose enough. I originally thought I'd have to pull that line completely into the car to get to the flare nut to remove it. I only had to pull the hard line into the car 3-4 inches to be able to unscrew it the rest of the way. I did indeed take the hard line out of it's connection with the flex line, that's the first part of the line discconnecting I did.

Throughout the whole exercise, I used brake cleaning aerosol spray to hose off the dirt and debris from the fittings, just like I do when I installed the "Big Brake" upgrade on the "is", and stainless lines on the e30.



[Edit by fastpat on [TIME]1108414703[/TIME]]