Technical Banging handbrake 2.8jtd maxi

[toyogran]

I applied my handbrake just before my motorhome came to a stop when coming to the top of a hill and there was an almighty bang from the the rear brake drums and a bit of a shudder.
Can anybody advise me if this is a Ducato thing (it has the top hat disc/drum fitted) or is there something seriously amiss?
Have Googled it and there are a few references of the problem.
Have checked Elearn and found the recommended adjustment procedure but is there anything else I should do to avoid this happening again (other than not apply the HB whilst moving).
Any advice welcome.

 

[cris1117]

Hi. I can’t think of anything that would make a loud bang and stay intact, if the handbrake still works O.K I wouldn’t worry too much.

I’m thinking that perhaps the rear wheels just locked up, sound like a seriously good hand brake.

 

[moodrater]

I applied my handbrake just before my motorhome came to a stop when coming to the top of a hill and there was an almighty bang from the the rear brake drums and a bit of a shudder.
Can anybody advise me if this is a Ducato thing (it has the top hat disc/drum fitted) or is there something seriously amiss?
Have Googled it and there are a few references of the problem.
Have checked Elearn and found the recommended adjustment procedure but is there anything else I should do to avoid this happening again (other than not apply the HB whilst moving).
Any advice welcome.

Th energys got to go somewhere when brake lock the back wheels it twists the axle on the springs, pulls the rear down onto the spring assisters (if you still have any)

 

[toyogran]

Thanks for the responses and likely explainations.
Yes, the brakes are quite fierce on the handbrake and considering it's only supposed to be a parking brake seem quite effective.
Someone has told me that a possible cause is the handbrake being adjusted via the handbrake cables/rods rather than the castellated wheel thingy inside the brake drum. Apparently the number of turns back from the drum being 'locked' is important when adjusting the castellated wheel for the correct shoe clearance.
Will give it a try at the weekend and let you know.

 

[fenman]

One of the problems with this type of handbrake is that because normal braking is done outside the 'top hat' the internal friction surfaces get very rusty. This means that if you apply the handbrake whilst moving it is likely to bite quite viciously. This is made worse by the fact that the shoes normally 'float' to allow self-centring so the free movement is suddenly arrested as they hit the stops. One of my cars was a Vauxhall Carlton which always clonked if I applied the handbrake whilst moving. On another vehicle I owned with this arrangement the adjustment procedure called for it to be driven at low speed for a short distance with the handbrake applied a few clicks to clean the drum before attempting the adjustment. I don't personally like this design as the drum, by necessity, has to be quite small in diameter. I like to have a handbrake that can be used to stop in an emergency if a problem arises with the hydraulic system and I haven't found the disc/drum type to be very effective in doing this.

And yes, the shoe adjusters must always be adjusted first with the cables slackened off to give the correct clearance after which the cables are adjusted to give the required number of clicks.

 

[toyogran]

One of the problems with this type of handbrake is that because normal braking is done outside the 'top hat' the internal friction surfaces get very rusty. This means that if you apply the handbrake whilst moving it is likely to bite quite viciously. This is made worse by the fact that the shoes normally 'float' to allow self-centring so the free movement is suddenly arrested as they hit the stops. One of my cars was a Vauxhall Carlton which always clonked if I applied the handbrake whilst moving. On another vehicle I owned with this arrangement the adjustment procedure called for it to be driven at low speed for a short distance with the handbrake applied a few clicks to clean the drum before attempting the adjustment. I don't personally like this design as the drum, by necessity, has to be quite small in diameter. I like to have a handbrake that can be used to stop in an emergency if a problem arises with the hydraulic system and I haven't found the disc/drum type to be very effective in doing this.

And yes, the shoe adjusters must always be adjusted first with the cables slackened off to give the correct clearance after which the cables are adjusted to give the required number of clicks.

Thanks for your technical input I can understand the problem better now and will try your tip for removing any surface rust before adjusting. The rear brakes linings were replaced before I bought the motorhome so maybe they need a bit of bedding in time?
For something completely different how do you 'thank' somebody on the forum for their advice? Can't see a link anywhere.

 

[varesecrazy]

Thanks for your technical input,

For something completely different how do you 'thank' somebody on the forum for their advice? Can't see a link anywhere.

look for the orange head with a white "grin" at the bottom right of a post,
1 click and You've done a "thanks,",
Charlie

 

[toyogran]

Thanks Varesecrazy another mystery solved!

 

[varesecrazy]

Thanks Varesecrazy another mystery solved!

you are welcome,
Charlie

 

[toyogran]

Just an update on the banging brakes for anybody else that has had the same problem.
The guy who did the MOT got the shock of his life when he applied the handbrake with the wheels rolling!
Took the top hat brake drums off the rears (after struggling with the caliper retaining bolts which were **??++** tight) and filed a good chamfer on the leading edges of the 4 shoes.
Result no more banging brakes.
The floating shoe design 'grabs' the the brake drum if applied whilst rotating but the chamfer allows the handbrake to be applied whilst coming to a halt without the allmightly bang!

 

[Willum]

Exactly the same problem but just on the first rear axle of a Alko tag axle chassis. Big bang and the wheels locked.
Cured by taking the brake apart (same 'kin tight calliper bolts) and finding one of the shoes on each side would no longer readily 'float' - rust/muck.
Cleaned it all up, a 'waffer thin' smear of HMP grease on the pads on the brake plate where the edges of the shoesrub they and hey presto, a wonderful handbrake again.
I too filed a chamfer on the leading edges but I don't think it was the cure. The 'stuck' shoes were the fault.
Willum

 

[panlap]

If its an Alko chasis be aware that the slightest 'binding' of the cable ( usually caused by the clips on the swinging arm having bitten into the cable sheath and caused the steel armouring to corrode and pinch the inner cable ) will make it impossible to adjust the handbrake shoe correctly as the shoes won't release fully.
The clips, which hold the cable away from the tyres had been closed/hammered over too tightly, cutting through the outer covering and this fault cost £100's to find on my last Bessacarr MH.