Bedford TK rear park brake setup.

[Opalminer72]

Jim.
Thank you I had a mate push and hold the broken air line in. You can see the piston slowly move to release the park brake just need now to get fitting for the air line
Lifted the back end up with a back hoe and wheels now spinning
You will need air pressure to get the hub off or adjust the brake shoes wind them off
Then use a puller to slowly work the drum off.

[mylesdw]

Originally Posted by RustRemoverJim

... the rods push from the central mechanism and into the cylinder on the drums when the air pressure is applied.

Small detail but they are pull rods.

[RustRemoverJim]

Got my parking brake mechanism on the bench this morning, when I apply air pressure the rods push outwards towards the hubs. Or they try to, needs some TLC. Having said that, I’ve only driven it 50 meters and the brakes were sticking. Is there 2 types? I’ve put a photo of mine. I got the hub off by disconnecting the park brake rods and rigging up a puller. The adjuster just span in the crown shaped gear, but it came off any way.

[mylesdw]

Looks pretty similar to mine but I think some TKs don't have air at all - vacuum brakes.

NB: rods are missing here

[RustRemoverJim]

I have just realised that you the author of the blue tk restoration blog which I have been reading over the past few months and using as a source of info when I get stuck. Best bit of info on the internet about TKs that I have come across. (I’m just buttering you up before I ask a load of technical questions!).

[mylesdw]

No problem, just ask away; I have a lot of pictures!

Truck is standing in the yard at the moment and I haven't driven it in a while. We had some sort of virus going round in the autumn and were not allowed to travel for a while.

This group has some very knowledgeable people on it

https://www.facebook.com/groups/1198517853610561

[RustRemoverJim]

I’ve got one rear slave cylinder and shoe expander mechanism off and it appears obvious that the rollers need to be pulled up the wedges in order to expand the shoes. I have triple checked my set up and it pushes the rods when pressured. My set up must have been wrong before it seized up. I’m thinking what could be wrong how to correct it. Wedges are upside down? The rods go to the wrong side? or my pressure pot pushes when it should pull? Looking at your pressure pot (assuming it is not pressured) and the leaver positions, it looks like it will pull, is that so? Am I missing something simple or just confused.
I will have a fresh look at it next week, beach and booze this weekend.

[mylesdw]

It sounds like it's working fine. When the handbrake is on, there is no air pressure and the spring brake pulls the rods, which pulls the wedge which expands the shoes applying the brakes. When the handbrake is off, the air pressure compresses the spring brake, which pushes the rods which pushes the wedge which releases the brakes.

For the handbrake the spring applies the brake and the air pressure takes the brake off. It's a fail-safe thing - when there is no air pressure the brakes come on.

[RustRemoverJim]

Back on it today. Of course, that’s so simple but I just couldn’t see it. As my dad would say, ”you can’t see the wood for the trees”. I had wrongly assumed pressure = brakes on! I can just focus on the rust now. Lots of cleaning and painting in progress. Thanks.

[mylesdw]

Looking good.

On the subject of spring brakes and dismantling them - don't.

(In case you didn't already know that)