Unbelievable brake master cylinder rebuild

[mercrocker]

I suppose when you think about it they are virtually a miniature rifle barrel....

[Scruffy Bodger]

Brilliant, enjoyed that ta (yes I'm easily pleased). Amazing anything was salvageable from the initial photos.

Always good to have access to the proper kit, oxy and a blaster are most useful. It's certainly quicker than soaking stuff in white vinegar anyway.

[mercrocker]

I have a sentimentality toward old cars that doesn't seem to manifest itself in other walks of life (save Rock & Roll music) so to think that a small piece of that long-gone and almost completely vapourised old Austin will now survive in its original duty is quite heart-warming!

[angrydicky]

That's unreal. Much respect.

At say 25 quid an hour for your time how much do you think it has cost* you?

The most time consuming thing was actually stripping all the unusable crap off it like the reservoir top, pedal, floor, etc etc. Once all that was off it was straightforward. I can’t remember how long I spent on it as I was doing it in lunch breaks at work but I would guess no more than three hours in total. I didn’t do the sleeving work myself and the plating is farmed out to another firm in batches but I did everything else.

[angrydicky]

Thank you for taking the time to photo and document that, it was interesting - I'm I right in thinking you used to do this type of thing down as past parts or am I on completely the wrong track.

Oxy Acetylene is incrediably handy!

I did yes. This was in Summer 2020, in that strange period where I ended up back at work and thought it would be nice to see if it could be saved. All the equipment belongs to them and I no longer work there, I’ve worked in a couple of different jobs since leaving but I’m still friendly with the lads there and they’ll be sleeving the other cylinders on the A30 if they need doing.

The thing that is worth remembering is no matter how good the equipment in a commercial environment is, there’s usually a way of doing it at home for a fraction of the price. Not quite as quick or efficient but at home I use a big grease gun for pumping out cylinders. I bought myself a 3/8” grease nipple and then an M10 one when I was rebuilding the calipers on my mates Renault 16 and needed to shift a stuck piston. It hasn’t failed me yet but for any seriously dry and rusty cylinders, another tip is to pop them in the oven for 40 mins at 180 degrees, then give it a pump. Seriously!
Most master cylinders are much easier to strip and if you look at the photos when I was trying to get the piston out, you’ll see it upended in the vice with the front of the bore full of penetrating oil. Normally with careful use of a hammer and punch you can tap the piston down a bit and then flip it over and bang the end on a piece of tube on the bench and keep repeating and the piston should drop out.

[BenHar]

I suppose when you think about it they are virtually a miniature musket barrel....

FTFY

Ben

[Scruffy Bodger]

I suppose when you think about it they are virtually a miniature hand mortar launcher....

FTFY

Ben

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FTFY

[angrydicky]

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Back in its rightful place!

The brakes on this A30 have been subjected to work from Billy Bodger. They were all seized so I stripped them all off and pumped out the pistons. The boot lip on the frame cylinder was smashed to pieces, and with two of the wheel cylinders, someone has attempted to ream them out but they’ve used a reamer that’s far too big. They’ve forced it in anyway and cracked both bores. One is only the boot lip so should be salvageable with a sleeve but one is too far gone so has been replaced with a good secondhand unit.
All are being resleeved.
As for the pistons, one was broken completely with the adjuster ring missing, one had broken and been brazed back together (but was very loose, one was missing teeth and one looked ok. Fortunately, they’ve been remade to a decent standard since I was last involved with these cars so I’ve ordered a set of new pistons with seal kits to fit when I get the cylinders back from resleeving.
On the plus side, the shoes were in excellent condition and don’t look like they’ve been used.

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[treehugger]

Astonishing. Would have thought it was scrap. Amazing how the metal survives... Or maybe not? Suppose the inside is protected by the rotten outside.

[DodgeRover]

Scarey whoever reemed the cylinders must have known they had damaged them but still intended to use them