any ford pop experts? rear brakes

[SUMO]

im having an issue on ford pop axle / brakes on the trike

a] brakes are crap - im sure this is my lever setup though so i can get over this by just re doing the linkage and changing more maths - ignore this fault im just venting 

b] rear right wheel sticks on.

the cable is slack so its in the brake somewhere. with it all installed on the trike but no drum on it works faultlessly. as soon as i just push the drum over the shoes if i pull the brake reasonably hard it locks on. it releases if i turn the wheel 1/2" backwards but doesnt if i turn it forwards. or i can free it by getting some mole grips on the swaged bit of the cable that enters the drum and pushing it.

i have new shoes in there but they are correct and not dragging when the trike is rolling. also i filed down the leading and trailing edge already

im open to any ideas. its pissing me off

[terry t]

Hi SUMO. are they cable or hydraulic brake. any photos of set up. terry

[SUMO]

cable, no new clean pics - its underneath - heres old dirty pic

but its just a standard cable setup, nothing fancy. and as i say its not anything outside the wheel like routing etc as it all functions great till the drum goes on - see diagram all well till i put on drum [1115]

any ford pop experts? rear brakes

any ford pop experts? rear brakes

[Manky Monkey]

Drum not true? -oval, rather than round?
Or the braking surface inside the drum tapered rather than true & square to the face of the shoes?
A lip worn on the back edge of the drum? I once had a problem on one of my Moggy Minors -the drum would pop on over the shoes but the braking surface had worn down, leaving a lip around the back edge. When I braked hard the shoes would ride up onto the lip & jam on.
Excessive scoring of the braking surface of the drum, causing the shoes to "stick" to it?
Is the operating cable properly anchored to the back plate? Maybe the outer sleeve is pulling out of the back plate when the inner cable moves & holding the brake on?
If yo've got access to a lathe, it's probably worth spending a few minutes spinning the drum up to check it's running true.

[SUMO]

ill have a measure up and see if it will fit in my lathe.

will also have a look and see how bad wear is. didnt strike me as terrible though.... that bloody shaun and this dodgy axle he soldme for a small fortune 

anyone got a couple of spare drums laying about if i do need em?

[SUMO]

another quick thing - it does it when just standing not only when moving - would that possible negate the oval drum / lip argument?

[Manky Monkey]

You're asking me -like I'd know?! 
I'm not an expert on anything. I guess it would depend what point of the oval the wheel was at when you tried it -does it lock all the time? Have you tried jacking it up & turning the wheel, trying the brake at various points? If it only gives problems in certain positions, that'd pin-point which area of the drum is at fault wouldn't it?
Can't actually remember what happened to my rear axle -I think Shaun had it, along with the orignal Pop chassis, so it might be the one you've got!

[SUMO]

ha - could well be this one here in that case

i ask like you might know? you make such a convincing job of sounding like you might know...

as for sticking - any point on the wheel - its not proud, it f**ks with me all the way round

[spanners]

sounds like  a rough drum  or a lip on the inner edge  i.e furthest out away from the back plate  i,v come accross the same sort of thing on commercial vehicle,s

the new linings maybe ever so slightly wider than the area the old one,s conntacted with the drum

[Manky Monkey]

Sounds plausible to me Mike.
I work hard at appearing to be a complete idiot here. Tis my job to ask the questions others are too scared to in case they make themselves look stoopid. I think I play the part rather well. 

[spanners]

 

[terry t]

SUMO. are you using the rod setup or cables. you say if you push the cable back it frees up the brakes. these brakes were designed for rods with a big spring to pull it back when you release the peddle. to release the shoes from the drums

[SUMO]

this one has a cable stock into the brake plate. then rod off the crank just to the right of the diff going forwards to all car bits, that rod i have replaced with a cable, but the cables from the crank to the brake plate are stock parts.

[tbone]

Have you got an exploded pic of the brake system? How do the shoes operate, do they have return springs fitted?

[SUMO]

yep return springs fitted - they are much the same as any drum brake with the 2 springs across the middle.  they work and return just fine without the drum on