Seized bits (drum brakes)

Hello FOAK.

I have a brake panel from an ER5, I've got the shoes off, the back end
of the bike looks terrifyingly like it'll never go back together. But I
have found the source of my lack of rear brake.

The cam shaft is stuck. It needs liberating so that I can clean it all
and wedge lots and lots of grease in there.

There's plenty of crap stuck in all the bits and bobs which all needs a
good clean, but the metal underneath looks shiny.

I could take the unit round to the friendly garage round the back of the
houses, but that's not in the spirit of self bodging.

Any advice?

(get a less pikey bike is *obvious*, but I'm determined to buy a
thundercat without resorting to credit which will be in December/January)

 

Heat, plusgas, lever back on, pipe over it as extra leverage, pull to
and fro, hit end of cam shaft with soft faced hammer, repeat.

Take it to the Black Horse next Saturday.


--
+----------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster [ SPACE ! ] Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
+----------------------------------------------------------------+

 

Blat all of the crap off with a pressure washer, dry off, then put it
in the oven at about 140C for an hour.
While its still nice and hot squirt a load of diesel (WD40 at a push)
into the jammed bits, the cooling effect will suck it in.
Now grab the lever with a suitable longer lever[1] and work it backwards
and forwards until it frees up (more oil) and it should come out.

[1] Lump of pipe, socket on an extension bar, mole grips or a pair
of stilsons if you dont mind damaging it. In stubborn cases it helps
to tap the lever each way wiv a nammer.

 

Hmm, heat I don't have any of, but it does already move a *bit* with
violence. I wan't *sure* repeated violence was the way forward. Is the
heat vital to avoid shattering the stuff? It's not exactly *cold* out.

What's on at the black horse?

 

Just soak it with Plusgas or any decent penetrating oil then keep
moving it backwards and forwards until it comes free. I wouldn't
bother with heat unless it was seized solid because you've got a
chance of distorting it if you don't heat it evenly.

Nothing much. The Stafford show is on over the weekend so a couple of
us are stopping there on the Saturday night and doing the normal drink
beer, eat food and talk shit kind of thing.

I suspect it'll involve me telling TOG he's a pussy bitch because he's
wimped out of next years winter tour and him agreeing with me but
still not coming.

 

Differential expansion rates of dissimilar metals. Needs to be proper
hot though. As crn said, an oven will do. Bit slow though, I favour a
precision blow torch or hot air blower.

Après Stafford Classic Mechanics show drinkies. Well practised SOB
bodgers in attendance.
--
+----------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster [ SPACE ! ] Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
+----------------------------------------------------------------+

 

Good point. I have got away with it using a blow torch in the past, but
on SO Brit and Italian bikes made with decent thick alloy castings.

--
+----------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster [ SPACE ! ] Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
+----------------------------------------------------------------+

 

Don't forget that if you just heat up the seized area the material
will expand into the bore as well as towards the outside of the
casting so unless you leave it to cool down and hope that the
expansion/contraction has freed the parts it'll be locked up solid.

Because the parts are already moving it's probably a waste of time
apart from the entertainment value that comes from playing with fire.

 

I find a squirt of Plusgas or similar once good and hot sometimes does
the trick.

True, if it is moving a little already it shouldn't take too much
persuasion.

Heh, Plusgas burns really well DAMHIKTIJDOK.


--
+----------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster [ SPACE ! ] Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
+----------------------------------------------------------------+

 

Heat, lots of, and hit it wivva hammer.

 

Ah yes, you too, huh?

 

The next thing to seize is the brake lever pivot on the mount plate. While
you have it stripped this far, it'd be worth doing that bit too.

Take the shoes off, put the actuating arm back on, blather with plusgas,
diesel or gt85. Go for a coffee. Work the arm back and forth. Whack with
moderate re-education force on the cam side then the lever side.

Reblather it.

Repeat until bored.

When it will finally rotate, remove the actuating arm and tap the cam out.
Clean all the guck from the spindle, then get a drill bit, wrap wet'n'dry
paper round it and get all the corrosion out of the hole in the back plate.

Apply a waterproof LM type grease to the hole ( oo-er ) and the pivot,
packing grease in to the groove in the pivot, and a very thin smear of
copper grease to the front shoe locating pin and the cam faces.

Reassembly is the reverse of dismantling.

I'd recommend doing the lever pivot and working some GT85 or whatever in to
the brake light switch too. Quite possibly the most awkward brake light
switch location known to man.

 

well, Halfords didn't have any plusgas, but I got some nice WD40 which
it's sitting in in disgrace, I've got it moving as much as I can wiggle
the brake lever by hand, with a bit of grunt, and with a knock wiv an
ammer it's come part way out of it's previous resting place.

Hopefully by morning the WD40 will eat it's way through enough of the
grime to release it.

 

well, Halfords didn't have any plusgas, but I got some nice WD40 which
it's sitting in in disgrace, I've got it moving as much as I can wiggle
the brake lever by hand, with a bit of grunt, and with a knock wiv an
ammer it's come part way out of it's previous resting place.
[/QUOTE]

Plusgas is the champagne of penetrating oils (ooh err), but WD40 will
do.

Time is a great healer, however, if you do need to resort to heat now
that it is soaked in stuff be cautious. As a great golfer (whose name
escapes for the moment) once said, "if you want to hit the ball further,
hit it a bloody sight harder."


--
+----------------------------------------------------------------+
| Pete Fisher at Home: |
| Voxan Roadster [ SPACE ! ] Yamaha WR250Z |
| Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
+----------------------------------------------------------------+