Bedford J1 Brake Cylinder Bore Diameters

Hi all,
I have a Bedford J1 and was wondering what the bore size should be for the front and rear brake slave cylinders?

I have 1.32"on the fronts, but as of yet have been unable to remove the rear cylinders as the internal bisector pull rod is frozen. (Took me two months to release the hubs, now I have a similar problem on the slaves)

Additionally, I have a vacuum booster on my truck but everything I read seems to indicate I should not. I was wondering if this is a factory fit or something that a previous owner has added?!

Does anyone know if the bisector plungers should have a marking to indicate their angle?
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Chassis Number:
J1C2 17545311

Engine number:  2/J1/2/3   158183

ID Tag (Build plate?)
M004316

BODY: TJ CAB-20971
TRIM: 502-1007
PAINT: 568-9857

 

Don't know  about your booster but it is something that can be bolted onto any non boosted brake system. Like fitting a VH44 onto early Holden 

Thank you.
I realise that any booster can be added but this one seems to be an original Bedford one, possibly from a bigger J series. Makes me wonder if any of the other brake components have been swapped out?!
Here are a couple of pics of my booster;
www.splods.com/

I have 1.32"on the fronts, but as of yet have been unable to remove the rear cylinders as the internal bisector pull rod is frozen. (Took me two months to release the hubs, now I have a similar problem on the slaves)

There is a specific way to remove the rods. Remove the little grub screw/bolt which stops the rod from turning. Then undo and pull. The rod has to be undone/removed  before the "wheel cylinder" can be removed.
 

Hi
I have removed the little screw at the top (and bottom of the other side)
I have a manual and followed the directions to the letter, but I feel the whole cylinder is too far gone with rust ingress well inside the bore.
I am at the stage where if I put too much twisting force on the rod, it just tries to lift out and round off whatever is inside the slave. I gather it is a slot type of arrangement.
I am currently soaking it with oil, diesel and will try a bit of heat next time.
Thank you for the advice and help.

I'm not sure if heat will work.

The handbrake rod has to be pushed inwards so it keys into a slotted nut. The slotted nut is screwed onto the Expander/bisector bolt.  This is inside the hollow piston.

Somehow, you've got to get the slotted nut undone.  Once it is, then the whole cylinder can be removed from the hub/plate and then disassembled.
The expander/bisector won't come off until the slotted nut (inside the piston) is removed.

You might be able to remove the bisector plungers  and cover plate. Then, this could give you access to being able to rotate the bisector bolt from the other end.

(and, silly qustion, but are you turning the rod anti clockwise?)

 

I can engage the slotted nut but it won't budge. I am worried about breaking something or burring the slot.
Your idea of dismantling from the bi-sector end might have some merit. I'll give it a go next weekend.
I intend to get the slaves stainless steel lined if I get them out without too much damage.
If I could find some replacements I would gently cut the current ones off with an angle grinder, but I need to source some first.
Yes, I am turning the rod anti-clockwise. Doesn't hurt to ask though.

Don't break them.  They are between $400-$600 each out of England. You'll find them on ebay AU and ebay UK.  There is a bloke in Cypress who also has a lot of Bedford stuff. He lists on ebay AU too.

An idea,  you could possibly remove the Bisector bits, remove the inside circlip (rod end) and try pushing the piston out outward. It may create some space to direct a flame into the cavity and free up the nut.  Thinking about it some more, heat on the outside might free up the piston too.

They have to be SS sleeved. Otherwise the seals will tear . I had mine done in the bus abouy13 years ago.  Good luck.