brake drums help please

[leroiandjayne]

iv recently fitted new brake shoes but even after fully adjusting the handbrake cables to max iv got very little handbrake stopping power at all,one of the last shoes actually disintegrated so they were old,can anyone tell me how thick the drum is supposed to be before its replaced,handbrakes cables were replaced not toooo long ago so shouldnt be too stretched,any ideas please, many thanks in advance leroi

[Oldiebut goodie]

Did you adjust the new shoes with the handbrake off?

[leroiandjayne]

yes at the second click,thinking on a mate said 2-3 years ago when he measured them with a gauge that there wasnt a lot of use left in them

[AdrianC]

even after fully adjusting the handbrake cables to max
handbrakes cables were replaced not toooo long ago so shouldnt be too stretched

You've got two adjustments on the handbrake.

You've got the cables - and once they're fitted, the adjustment is ONLY to take up stretch.
You've got the shoes - and the adjustment should be automatic for them, and affects the footbrake, too.

If the handbrake is pulling the shoes on properly, you're running out of travel on the lever, and there's still no retardation there, then the rear brakes themselves can't be doing much either, because the same shoes do both.

The maximum diameter for the drums is marked into them, but if you've got the shoes contacting them properly, then that isn't your problem. I'd start by looking carefully at the surface of the shoes for contamination or glaze, and looking at the surface of the drum for glaze. Can the wheel be rotated by hand, with the handbrake fully on? If you jack the back end up and put the van in gear, how easy is it to stall against the handbrake?

[leroiandjayne]

nice one many thanks for that but when you say"glaze" what am i looking for?,i did buy the new shoes about 2 years ago and theyve been unopened in the box eversince but it turned out that the cables were totally shot,so when replaced them the brake was fine,but,since iv put the new shoes in 6 weeks ago iv got bugger all purchase full stop!iv fully wound out the adjusters and i cant pull the handbrake any further up without elbowing the roof! so iv just bought complete kit from D.E consisting of brake shoes,twin cables,drums and pistons so..no more from JK .busy weekend eh...

[leroiandjayne]

checking her history,these have coverd 238k! so maybe they are a little thin!!!

[Aidan]

the wear limit is actially cast into the drum it says 10.something inches iirc, I don't have access to Bentley or any other published measurement
basically if there is a lip on the drum of much more than a mm they will be close to or on the limit

[CovKid]

or knackered in 80/90 jargon

[paperhouselad]

The new shoes could only be contacting on the lip, not the previously worn braking area of the drum, giving very little contact area, hence poor handbrake.

[tonytech]

It might be a stupid question, but you did wind the brake adjusters up (the one you get to from behind each drum)

T

[CovKid]

Does sound to me like handbrake cables themselves have been adjusted rather than using adjusters at back of hubs. That mistake has come up a few times on here. Pain to get it back to where it should be if that the method is adopted. The automatic adjuster inside hub (even when greased) rarely works as it should, or at least not for long. Other than when fitting new handbrake cables, the only adjustment needed is at wheels. With new drums thats even easier to do.

[leroiandjayne]

hi chaps thanks for the feedback,i pumped the brakes when the drums were off after servicing the mechs and the auto adjusters clicked out just fine (had to wind em back with a screwdriver!pain) so i know they work,i then pumped with hubs on and could here em clicking until they tightend up,now a few weeks on there is slight amount of bite but not much so have got a complete replacement kit,2xhubs,new shoes,2xcables,2xpistons all decent German kit for £95 inc courier!!,so on it goes!!

[tonytech]

As I understand it the auto adjusters are designed to take up the small amount of play caused by the shoes wearing.
The initial play should be taken up by the ratchet screw.
It really sounds like you are replacing stuff for the sake of it.
Set it up properly or you will be replacing it again in a few months.

T

[leroiandjayne]

[AdrianC]

ok,so where is this "ratchet screw" you mention?

I think Tony means manually pre-setting the screw-and-ratchet in the autoadjuster.

but i do think the drums are worn out

Have you measured them?