Clutch master cylinder mk3

The clutch slave failed – not sure why, perhapse the master cylinder was pushing too much fluid into it. The reason is not so important, I’ve decided to use the BMW master cylinder as this will be matched to the slave. Unfortunatly the original design for the clutch attachment is very poor – the whole pedal box twists.

Therefore I’ve started protyping a new bracket design that will be a strong mount for the master cylinder with a bracket the bolts up through the top of the scuttle – already re-enforced for the pervious alternative clutch arrangment.

I’ll 3D print this bracket for test fitting and if it works OK I’ll try to recreate this in aluminum.

clutch bracket


clutch bracket printing

A couple more hours:

clutch bracket printing 2

Engine Work

Adjusting valve clearances and a new rocker gasket

Fix the jump leads – no continuity = useless jump leads. The copper was crimped and cut straight through at the factory. Trimmed and now soldered – much better.


Inside the rocker cover still looking very clean. Adjusted all the valve gaps to 0.25mm, glad there are only 12 valves to do! Most needed a little tweak. Also gave the oil spray bar a good clean out with brake cleaner while the cover was off.


The rocker gasket was a bit very second hand, luckily a local parts shop had one in stock.


Engine Work


Service time!

New oil – fully synthetic ester


Managed to avoid spilling anything on the ground for a change!


Being able to take the side off the engine bay really makes filter swaps easy!


Also done is 6 new spark plugs (they’re pretty cheap so why not!)

Found a minor vacuum leak so the idle is much better now.

Engine Work

New 6 speed gearbox

The current clutch slave is about to pop, the mechanism for moving the clutch in and out appear to be overly stressing the hydraulic components.

As Iโ€™ll need to take the gearbox off anyway so it seemed like a good time for an upgrade. Apparently the ZF 6 speed from the E46 320d is a straight fit and as a bonus the same angle as the M20, it’s also a more solidly built and younger than the getrag that’s in there now. Only down side is that I might need a different final drive ratio to make full use of the new ratios.

One eBay special later:



But the shift linkage at the top was smashed in transit ๐Ÿ™


So decided to try and fit it using HTS 2000 brazing rods. I tired this with propane but it wasn’t hot enough. I instead got a can MAPP gas and a new burner from B&Q:





Braced with a bolt and a custom cut piece of rod





Seems pretty solid, will see how long it lasts!

Engine Work

New Optima yellow top battery fitted

Bonnet (hood!) off in Roadkill tradition, but to change the battery, not overheating ๐Ÿ˜‰

The old bosch has taken too much abuse over the years and doesn’t hold it’s charge that long even after conditioning on the CTEK charger.


Pulled the battery out, gave this area a bit of clean. Ther rubber disks are actully old bump stops with the tabs cut off. Gives a sold yet slighly squishy place for the battery to rest against.


New battery is an Optima Yellow Top R 3,7 D35 deep cycle. It’s a little bit smaller than the old battery. CCA is 660. The terminals clear the battery which makes it much easier to put charge clamps on them.


Don’t forget to change your charger setting to ‘AGM’ if you don’t there’s a risk of overcharging – which will end up venting water than you can’t put back in.


Cold start and luke warm start:

Engine Work

MTX-L Calibration

Calibrated the sensor today on the bench.

Important note – the big plastic plug that you connect to the sensor has a little plastic tab which stops the plug coming undone without pulling it. If you connect the plugs without lifting it then it can very easily go the wrong side of the plug (inside) and stop it connecting up properly. You’ll know it’s right when you hear a click as it slides into place – as below:


First step is to hook ground and power up to the gauge with the lambda sensor disconnected. It will display E2 on the screen, wait 30 seconds and take the power off.

Plug in the O2/wide band lambda sensor and reapply power.

The sensor will get hot:


HTR will be show on the display for a period of time while the heat builds up. My bench power supply showed between 1.4 and 1.7 amps being pulled while it was doing this.


It briefly shows CAL is the display while calibrating the switches to 22.4 as it is in free air:


That’s it ready to go in the car – don’t power it up without the lambda sensor attached or it will reset the calibration.


Servo upgrade complete


Paint on the back of the adapter to avoid any rust


A tube ofย  heat shielding goes over the brakes hoses, this adds extra heat protection as they run past the servo underneath it.


The most useful tool ever in a situation where you can’t see – a camera on the end of a long bendable probe!


Snake cam, allowed me to easily locate bolts and screws while using the laptop screen to see what was going on.

With the aid of this tool I bolted up the rose joint to the brake pedal.


Old heat shield adapted and fitted under the master cylinder, the extra tube covers from the heat shield back.


The heat shield keep everything nice a cool as it’s directly above the exhaust manifold. The servo gets close to the side, but there’s more than enough room!


Lots of clearance for the bonnet to close.


Here is is all back together again! Took it for a quick test drive, it was cold dark and the first time I’ve needed to use the fog light on the car!

Initial impressions – pedal travel is longer, but way more progressive. The feel is much more like my tintop – not as much bite but much easier to use.

Took it out again today and tried a few emergency stops, it stop nice and straight and you can pump the pedal relativity easily to stop the wheels from locking. All in all a very good upgrade!


Brake hose installation progress

Made good progress today installing the new flexi brake hoses from the master cylinder. The pressure reducer for the back is relocated just above the steering column and all 3 pipes have been chopped and re-flared.


Flexi pipes for the front brakes fitted to the chassis, the old brake pipes are still as there were.


Master cylinder adapter plate painted a nice shade of hammered blue.


Copper shortened and re-flared to fit flexi pipe locations and the pressure reducer for the rear brakes relocated to just above the steering column.


Pressure reducer as seen from the top.