Friday, August 28, 2015

Clutch Cylinders - Overhaul

After successfully removing the engine without injuring myself or damaging the car, which I'm pretty chuffed about, it's left behind a rather scruffy looking engine bay. As I've spent the last 9 months painstakingly rebuilding the new engine, painting and polishing every component to perfection, there's just no way it's going in without a bit of a tidy up first.

For that reason, I'm starting 'Operation Tidy the Engine Bay', not the catchiest of titles I grant you, but it explains things rather well. The first things that need to come out for beauty treatment are the 2 clutch cylinders. The slave cylinder is an easy job to remove, but the master is an absolute nightmare...


Removal
To be honest, the slave cylinder is kind of already out anyway as it was detached from the engine was lifted and left dangling down on it's hose from the engine stabiliser bracket.



Now at this point I need to explain a peculiarity about my engine stabiliser bracket. Way back in 2013, I noticed that the bracket had sheared and needed to be welded back on. As I didn't have a welder, I sought the services of a local garage to do the repaired.

To avoid disturbing the clutch hydraulics at the time and to make the job a bit cheaper, the bracket was split to separate off the clutch pipe and the remaining part was welded back onto the bulkhead with webs beneath for extra strength. The clutch part of the bracket was then bolted back onto the newly repaired part. Alas I didn't take any decent photos of the bracket, but I hope this zoomed in picture helps.



Now onto the real problem - The master cylinder which is bolted to the bulkhead with 2 small bolts. Removing them is the easy bit, it's what lies beneath, that's the nightmare!!



What can't be seen from above is the pedal linkage and what makes it such a problem is where it's located, as it's tucked away right up under the dash behind the steering wheel. The bottom of the clutch cylinder is connected the pedal with a clevis pin which in turn is held in place with a small split pin and both need to be removed.



Not to worry though as the ever helpful Haynes Manual is on hand with 5 simple steps! Reading step 2, it seems pretty straight forward...



So I duly removed the 'flexible air intake ducting' from the side of the heater unit and wow, what a difference it made - None at all! It didn't help in the slightest as it was still impossible to reach the clevis pin without arms the thickness of chopsticks and hinged in several places.



As there was a real space limitation to the point where I was getting my head stuck under the steering wheel, I decided to remove the drivers seat to lend more access. This made the job a lot easier as I could lie on my back with my feet on the back seats and my head under the steering wheel. However, I still needed magically thin arms to get at the clevis pin as the gaps between the pedals were just too small.



Next to come out was the heater as it gave me access to the left hand side of the clevis pin where the split pin was located. This really did help things along now as I was able to get my hands in there. Using a pair of long nose pliers, I was able to push the end of the split pin enough so that it could be extracted from the other side.


Now using a wooden kebab skewer (what else!), I was able to get it in the loop of the split pin and gently pull it free without dropping it down behind the carpet.



All that fuss for such a tiny little item!



Once the split pin was out, I was able to remove the clevis pin and finally lift the clutch master cylinder out. Phew, that was an effort!




Overhaul - Slave Cylinder
Now that all the parts are out and on the bench, it's time to check them over and make them shine once more. Starting with the slave cylinder; after removing the rubber dust cover, which was split, the innards of the cylinder were free to literally fall out... and fall out they did as they were spring loaded.



Once out, I must admit that I was expecting a little more than a single spring and a piston! Such an amazingly simple design!



After a general cleanup to get rid of the hydraulic fluid, the rest of the parts were stripped off and I got to work with a wire brush and a drill on the cylinder's outside walls to scrub all the crud away that had accumulated over it's many years service.

Once cleaned, it was given a light coat of chrome effect spray to both protect it and to make it look the business. The interior wall of the cylinder was cleaned along with the spring and piston and it was reassembled with a new rubber dust cover. I have to say that it looks slight better than when I started.



As for that tatty looking hose and banjo, well I'm planning a replacement that will look and work much better - Watch this space!



Overhaul - Master Cylinder
Now onto the master cylinder which is made from two main parts. There is the cylinder itself and the plastic reservoir.



They are held together with a metal strap that binds the cylinder to the reservoir, between the two parts there's a rubber ring that forms a seal.



Once separated, the old hydraulic fluid that drained out did look slightly past its best!



To clean the plastic reservoir, I used carb cleaner as it does a really good job of dissolving the black 'crusted on' stuff. Helped along with a toothbrush, it was soon looking like new again. As for the cylinder, I decided not to take it to pieces and simply gave the outside a brisk going over with the wire brush and finished off with some chrome effect paint.

Once the 2 parts were reassembled, it looked rather good, almost like new in fact.



Conclusions
Although I hadn't planned this amount of work when I set about swapping the engines over, it wasn't until the engine was out that I realised just how scruffy the engine bay looked. As certain parts of the engine bay are now accessible, there's no time like the present to tidy those 'usually hard to reach' areas, hence the reason for 'Operation Tidy the Engine Bay'.

Even though it's going to be a lot of extra work, it's going to be worth it as the renovated parts will not only look better, they will also work better. Looking at the bulkhead as well, I've spotted a few patches of surface rust here and there, which if left untreated would almost certainly turn into holes and holes are bad!

Anyway, I'll love to ramble on and on about how I love fixing my Mini, but I've got some brake components to demuckify and I love doing that even more than rambling, so I'm off to do that instead!




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