Clutch hydraulics

Clutch hydraulics part 1

When I got the car the brakes had some semblance of activity! There was fluid in the master cylinder and pressure at the brake pedal- true the brakes didn't seem to have any effect at all on the car's motion- but there was at least fluid! In contrast the clutch reservoir was empty and the pedal simply hung limply as a constant reminder of one of the most embarrassing nights of my life! It had to be sorted and  now whilst I consider my options for the engine, was probably the time. At some point water has obviously been a frequent visitor to the driver's footwell. I suspect the blocked air intake drain hose that I cleared the first day I had the car was probably the culprit - and might well account for the rusted HRS relay as well.

Anyway the clutch pushrod clevis pin and the cylinder securing nuts were rusted- I recommend anyone tackling this to wear some thick gloves while trying to remove these bits as the scratches on my hand bear witness. The cylinder is held in by 2 bolts, the lower is easily removed with a 12mm socket and extn, but the upper is blocked by the bulkhead. Here I was able to use my half moon obstruction spanner! Perfect and extremely gratifying as this spanner set has lain unused in my toolbox for around 5 years! When you need this type of thing its just the type of thing you need! (also access via extension bars and UJ)

Crud and rust visible under the cylinder boot

Site of master cylinder after removal note rust to mountings. Don't think this area should get wet, but there was no gasket present to keep water out of the car or off these bolts.

Anyway master cylinder off and over to the bench... not a pretty site. Removing the boot showed a load of corrosion around the base- nasty. I scraped this way, removed the base circlip and eventually managed to “pop” the plunger out of the cylinder body. To my surprise there was some residual fluid in the body which pumped out clear during this popping operation and when I eventually got the piston out, the inside of the cylinder was bright, smooth and unmarked!! Internal corrosion was limited to the exterior of the cylinder ie in front of the pushrod retaining clip.

Master cylinder disassembled, disc float from reservoir. All needs cleaning, note 90 degree elbow attachment adapter that accepts the clutchfluid pipe.

All the components cleaned up nicely in my sonicator bath and I was confident that it would be simply a case of getting some new seals and rebuilding- as I have done many times before with Girling and Lockheed brake/clutch parts. It doesn't always work, but when it does its a hell of a saving- and greener to boot. Here though I was disappointed! I simply cannot find anyone selling seal replacement its for these Toyota items... and although I did track down  cylinder repair kits at SJSportscars, these were priced only a few pounds short of the cost of a complete new cylinder which obviously defeats the object. Interestingly and in contrast, seals for the UK made brake system seem to be readily available. This means I will need to replace both cylinders completely- more expensive than anticipated but I guess more reliable a fix anyway! I resolved to order these parts at some point in the future- although this point isn't terribly urgent since at present there is unlikely to be any power from the engine that needs disconnecting- and will not be for some time.

If you do need these cylinders then its worth shopping around- slave is CV-200 and the Master is MC1602. Check orientation of the reservoir, 1600 will fit (and probably work fine) but when mounted, the reservoir is not vertical. I got mine from Amazon, but there are many equivalent code numbers from different suppliers so check those on a parts crossreferencing site and do a search on those numbers too. I ended up finding some around £20 and £35 each... although having said that the MC seems to be delayed and I'm hoping it will actually arrive rather than be cancelled!

Note added (considerably later)

New master cylinder did arrive and was stored until 04/07/2016 when I finally revisited the clutch hydraulics. New cylinder fitted easily but remember to detach the brass 90 degree adapters from the old cylinder as these don't come with the new one. I cut a new gasket out of silicone using the cylinder back plate from inside the footwell as a template for the hole positions and then mounting this on the cylinder to cut the edge profile.

Old cylinder- I saved the float and cap

...and removed the 90 degree elbow/banjo which needed...

...cleaning- I used the Deox C

Tapping out a new gasket from a silicone rubber sheet- I used the internal footwell MC bbacking plate to mark the positions of the holes

all holes cut out the square could then be slipped onto the M/C and...

New gasket trimmed to profile

Finally the new M/C was installed in position, bolts tightened and the clevis reconnected to the clutch pedal rod*. I will wait to adjust the pushrod length as at present there is no fluid and I still have to swap out the slave cylinder.

Installed

I will try to renovate the old cylinder as I did eventually get some replacement seals so for the time being I am storing the de-rusted cylinder coated in oil. See the section on the brake M/C for a general description of my approach.

*... All was not well... although I installed and connected the master cylinder to the pedal- it became clear later that the alignment between pedal and master cylinder was  wrong, forcing the pushrod to adopt a strange angle in order to connect the two- and this in turn prevented the master cylinder from working properly.. This is mostlikely due to a bent clutch pedal or pedal box which does seem to be a fairly common fault on these cars... usually caused by a siezed master cylinder and in my case that cylinder was clearly a problem. I think its likely to have been a problem even before I got the car as it had actually been disconnected by the LBPO. See my later post "Adjusting the clutch refilling the pas system".