Rear brakes

[myfirst69]

Hi all can anyone help me please my rear brakes on my 1970 keep popping the wheel cylinders and the star part on the star adjusters is actually breaking away from the threaded bit...any help please it's driving me nuts...I have replaced the cylinders and shoes...the star adjusters are new and so are the flexi hoses...I also replaced the master cylinder...handbrake cables are new too the only thing not replaced where the drums....Rog

 

[Toad]

Sounds like you have shoes that are too small/incorrect?

Got a photo?

 

[myfirst69]

this is a photo before drum put back on I dont have a photo of the failed star adjuster until tomorrow any ideas would be great.... :evil:

 

[67panel]

your hand brake cable is over adjusted(common fault)the crossbar should be against end of slot in shoe.

 

[myfirst69]

but would that cause the cylinder to pop and star adjuster to fail I mean the star split from the thread....

 

[Toad]

but would that cause the cylinder to pop and star adjuster to fail I mean the star split from the thread....

Never known a star adjuster break off the thread? They usually can take quite a bashing too....what are you doing to them? Unless they are poor quality ones made out of monkey metal or something...strange?

(Agree about the handbrake too) That may be why there is too much piston movement.

 

[myfirst69]

I'm not too sure what you both mean about over adjusted....can you explain where I got it wrong.....I'm going to get some photos of adjusters today...the handbrake was set up as per manuals is it the cable I got wrong or the shoes can I have a picture to see what you both mean please....Rog

 

[myfirst69]

here's what the brakes done to star adjusters and popped the cylinder too....any ideas with photo back up would be really helpfull....I carry my family in the bus and e love it but I gotta get it sorted...sooooon...Rog

 

[RePhil]

Rog,

The only way I can think that the threaded part of the adjuster could break off the star part is if it was adjusted to the absolute max & then keep going. The leverage you can achieve with a screwdriver through the backplate may be enough to shear old possibly tired adjusters.
Continuing to lever would leave the adjuster nowhere to go linearly but you could carry on rotating till it breaks.

Fit new adjusters fully back off the handbrake cable, adjust brakes per manual & then set handbrake.

For the seals blowing out, this can be caused by overtravel of a piston in the cylinder. This may be caused by very worn out shoes (yours look OK), very worn out oversized drums, or maybe wrong sized shoes & drums.

I would measure the drum ID & also place the shoes inside the drums & look to see if they "look" OK. I.e. are the shoes approx the same radius as the drum.

I hope this helps,

Phil.

 

[Rippers]

I agree with Phil, my guess would be the drums are beyond the wear limit, try and get a precise measurement across the drum from one inner wall to the other, I'll get the manual out and tell you what it should be

 

[myfirst69]

Thanks for replies I spoke to the gang up at Heritage who furnished my with a whole new set of star adjusters and supplied me with 2 nice new cylinders...thanks James T....we thought the drums could be an issue too so we measured a nice new one from the box...249mm and mine measured in at a respectable 248ish...

We have now built it all back up...thanks Mark...we marked off the star adjusters to see if in a couple of days if maybe the are moving with friction and adjusting themselves...I don't know what else to do...we adjusted the pushrod to master a little to make sure the cylinder has enough return room....so here's hoping

Rog