Removing the Slave Cylinder - Pt1

Having ordered the replacement brake master cylinder and slave cylinder, decided that I should get the old slave cylinder out so I would be ready to slip the new parts in as soon as they arrived.  So yesterday I went to get it done.  From what I had looked at before, I knew I wasn't going to be able to take it out without removing other assemblies.  I had already taken out the washer fluid bottle (not replaced since installing the slave cylinder reservoir) and the left side air filter housing (for accessing the Master cylinder).  This was the view I was left with:

Reservac Tank Blocking Access to Brake Servo and Slave Cylinder

The Slave Cylinder is behind and below the Reservac tank that's in the foreground, so that had to come out.  Doing so wasn't too bad - the hoses to the inlet manifold came off OK (I'd already had them off once to check the condition of the Check Valve).  The hoses connected to it were also not too bad, although a bit of prising was needed.  Fortunately all came off in one piece.  The one connection that stumped me for a while was the connection of the tank to the car body.  The bolt through the side bracket into the car body was OK, but I thought the bottom bracket was bolted to another bracket welded onto the floor of the engine compartment.  Turns out the tank bracket was just bolted through the floor.  So took out the tank to give me, at least better visibility of the Slave Cylinder:

View of Brake Servo and Slave Cylinder

The problem now was the fresh air intake hose.  That was a struggle to get off the stub out of the body, but came eventually, again, without damage.  However, when I followed the hose back to the intake itself, I found the hose split in two and kept together with a make-shift bandage - it will need replacing.
While I was getting the air hose off, I had left the Reservac tank to one side.  I had expected to see brake fluid come out of at least one of the hoses when I disconnected it, but nothing came out.  Now, when I went back to it, after leaving it lying on its side which allowed the liquid to accumulate near one of the outlets, about 3/4 of a brake fluid reservoir volume of brake fluid drained out.  I must admit, I was a little surprised at how much came out, but I shouldn't have been really, after the amount of pumping of the brakes I had done to try to get rid of all the air.

Now with pretty much everything out of the way, I could get at the connections to the front and rear brakes (via the PDWA switch) disconnected from the top of the Slave cylinder.

Now all that was left was to disconnect the cylinder from the mounting bracket at the front end, and the Servo from the car body.  Undoing the bolt from the front end wasn't too difficult, although it was awkward getting spanners onto both the bolt and the nut holding the bracket to the floor of the car.  Eventually got it, but with limited swing on the spanners, it took a while to get it loose enough to move.  The three nuts holding the studs on the servo were easier to get at than I'd expected - just involved lifting the carpet and insulation from under the pedals in front of the drivers seat and undoing them.  Once they were off, there was nothing else holding the Servo and Slave Cylinder onto the car:

Servo released from the bulkhead.

Now it was time to remove the Servo/Slave Cylinder assembly.  That's where I stopped for the day.  I had one try, and realised it was going to take quite a bit of manipulation to get the Servo, in particular, out between the frame.  It had taken me about 4 hours to get to this point, so I decided manipulation (and persuasion?) could wait for another day.  The only other thing I did was disconnect the fuel return pipe, because it lies right across the access between two of the bars of the frame, in the way of the route for the Servo/Slave to come out.

To try to fix the problem of burning brake fluid in the engine, I've started overhauling the brake system components.  As it's the easiest to get at, I've started with the master cylinder.  Following the instructions in the manual (and the paper that came with the overhaul kit), I've got as far as pulling the piston out of the body of the cylinder.  The instructions say it should just pull out, although to be aware that the o-ring could slip into the circlip ring and make it tight.  However, I can't budge whatever it is that's stopping the piston from coming out.

The bearing that guides the piston, jammed in the bore of the cylinder.

It appears to be the bearing that guides the piston that's basically jammed in the bore of the cylinder. It's designed as an interference fit, apparently with an o-ring part-way along it, so if there's any sort of contamination got into the cylinder (after 40+ years of use), that could cause it.  The piston itself moves freely within the bearing, but once it comes up against the "stop" at the open end, that's it - not even a little movement to suggest that it will come out.  I've tried pulling with padded (so as not to damage the surface of the piston) pliers, but still can't get anything.  I've also tried to lubricate the bearing with brake fluid, brake cleaner, and penetrating oil, but to no effect.

I've been told that the bearing often breaks eventually when trying to remove them from the brake cylinder, and that they're no longer available (it wasn't part of the repair kit that I had ordered).  So, even though I'd still like to know what the condition of the inside of the Master Cylinder is like, I've decided to buy a complete (Lockheed) master cylinder, as well as a complete servo assembly in the interests of time (and my sanity).  So all the parts have been left to one side and I'm currently waiting for the new components to arrive. (The delivery van actually called yesterday to drop them off, but it was during the only 15 minute period that I wasn't around to open the door, so now I'm waiting as long as I can before moving away from the front door, on the assumption that they'll re-try to deliver mid-afternoon today.  It's like being a kid again and waiting for the time to open birthday or Christmas presents).

The Brake Repair Kits Arrived

The repair kits arrived, so I set to and tackled the apparent challenge of removing the Master Cylinder.  It actually only took me a couple of hours to extract it from the engine.  It came out a lot easier than I expected.  The only problem I had was with one of the Nyloc nuts that holds the body of the cylinder on the pedal box studs - there wasn't enough clearance between the nut and the body to get the jaws of a spanner onto the flats of the nut in the only position I could get a spanner anywhere near the nut.  In the end I had to position the spanner in line with the stud and use an adjustable to get enough torque on it to remove the nut - fortunately the nut hadn't been over-tightened!

Master Cylinder with Parts waiting to be Fitted.

So now I have the Cylinder in the basement, with my new parts kit, all waiting for me to start the work.

Brief Update - lack of Activity

Haven't written anything for a while.  Basically I haven't done much on the car in the last couple of weeks.  I've been trying to make sure I understand the braking system, and to work out where the leak could be, causing the brake fluid to get into the engine.  Basically both the Master cylinder and the Slave cylinder are indirectly connected to the air/vacuum circuit through the Reservac tank, which itself is connected via a check valve to one of the inlet manifolds.  The Master cylinder is attached to the Reaction valve of the air/vac circuit, and the Slave cylinder is attached to the servo diaphragm. To verify this, and get some suggestions on what the cause could be, I submitted a post to the "Jaguar Forums".  I was grateful for the couple of responses that came back verifying my thoughts, and suggesting that the cause could be the diaphragm in the servo.

So I've gone ahead and ordered repair kits for the Master Cylinder, the Servo cylinder, the reaction valve, and a new diaphragm for the servo.  It was suggested that I may be better off just buying replacement cylinders because repairing them could be problematic, but I bought the car as a project to allow me to do a lot of the work myself, so I'm going to try the overhauls myself (as a back-up I can buy replacement cylinders, although I'm also considering cost by initially going for overhaul rather than replacement).  All the repair kits are now on order from SNG Barratt in the US - hopefully they'll be here within the next couple of days - they've already been shipped.

Even though the servo diaphragm has been suggested as the most probable cause, I'm going to start by overhauling the master cylinder and the reaction valve, basically because they're the easier to get access to, having taken off the air cleaner (again) - photo below.

Brake Master Cylinder and Reaction Valve

If overhaul of this system works - great - I'll be done for now.  If not, then I'll have to get into the Slave Cylinder and Servo.  These are a lot more difficult to get at, and I think I'll be looking at removal of the heater fan & motor and the Reservac tank to give me access to them.  You can just about see the servo unit in the centre of the photo below; the Slave cylinder itself is hidden by the bar; that's the Reservac tank on the right.

Brake Servo in centre of photo; Reservac tank on right and Reaction valve on the Master Cylinder at top of photo.

As soon as the parts arrive I'll get the Master Cylinder and Reaction valve off and overhaul them - hopefully in the next week or so.