Caravan Brake Squeal

Milothedog

As per title, anyone else have continual issues with this. Three times now my supplying dealer has had the hubs off to cure it.  This Friday, after a shower wall crack repair, they also looked at the brakes again, (This time they have used a new compound supplied by ALKO) got about 10 miles before it started again. In my working life in the motor trade I have always been able to cure it on vehicles but it seems a real issue on caravans.  If I kept the caravan at home I'd strip the brakes and investigate myself but I don't have that option unfortunately. 

Look forward to reading your replies     My Chassis is a BPW by the way, not ALKO and my previous Coachman on an ALKO chassis was nowhere near as bad as this is although it did squeal.

 

Jacko From Kent

Hi, we have a 2017 Swift Challenger with annoying squealing brakes. Not sure Milo if yours is the same but if you brake reasonably hard then the brakes are quite. If you gently brake then they squeal horribly, you can hear through closed windows and OH singing!!!

Dealer has had 3 goes at it and still no better, they have filed the leading edge of the shoes and tried all sorts of anti squeal stuff, it’s going back in soon for another go. Apparently there is a fix which is to cut grooves into the friction material

 

Milothedog

Yes Jacko, exactly the same issues. they have also tried putting a chamfer  on the leading edge of the shoes to no avail. I'm thinking maybe the drums need skimming to remove any tram lines in them? 

Squeal is caused by the high frequency vibration between fixed and moving parts of the assembly which is normally identified by looking for the shiny / clean bits where they contact each other and applying an isolator such as copper slip so I find it hard to understand why its such a persistent issue and so common place.  Some will argue that it's dust or rust in the drums but my working experience has proved to me that it's not the case.

Hope yours gets sorted, as I drove out of Alderstead Heath on Friday after dropping mine off there was someone just arriving with a very new caravan and the noise was worse than mine 

  

EmilysDad

I've only ever had discs/pads squeal .... 😞

asda160

Milo,

 

it it would be interesting to find out how bad the run out is on the drums internal ID is as no amount of copper grease on contact points will isolate the effects of resonance as it gets rubbed away eventually and you are back to steel on steel + excess run out = resonance 

If the drums are indeed oval then a skim or replace may be on the cards

Also how tight are the shoes held to the back plate by the securing hardware.

There would be nothing lost in asking for the drums to be swapped sides to see if the noise dissipates or swaps sides.

It is clearly an individual component thing rather than a design fault. My previous van with Alko squealed, my current van with Alko does not.

 

Milothedog

Thanks for the reply Asda,

We have a trip booked for mid September so I'm going to see what happens on that trip, i.e if it gets worse again or with a bit luck settles down?  I would have hoped when they had it apart they would have identified any weak shoe retainers. As you say swapping the drum/hubs side to side would be an interesting exercise but I don't think ovalality is the issue because you would feel it when braking?

asda160

Maybe oval is the wrong terminology. High or excess run out.

Resonance will be caused by the metal portion of the shoe moved against the break back plate in high speed minute movements exacerbated by run out of the drum which I think you already understand. It's the wine glass wet finger tip scenario. The faster the finger tip is moved the louder and higher pitch the squeal is.

So if there is excess run out the modulation of the associated brake components provides the perfect conditions for brake resonance. It's how you address isolation of the components and/or excess movement, which you mention copper grease but that is not a permanent solution.

Bendix brakes used to suffer with resonance/squeal and started providing a tube of silicone based adhesive with their brake pads.

...and would we feel ovality when towing? I'm not sure we would due to being isolated from the caravan by the hitch.

Milothedog

Again, thanks for your reply. Yes I do understand the cause but after many years working in the vehicle repair industry and having the facilities to do stuff for myself, frustratingly I have nowhere where I could pull it all apart to investigate for myself. I can't even pay a mobile fitter to have a look at it at the storage site as the club doesn't allow it    I put new pads and disc all round on my car last year outside my house but you can't really do that with a caravan  

I have from my working days a large tube of special silicon brake grease supplied by Volvo for Buses/HGv's to combat this problem (provided its not something else causing  it)  but as I say I have nowhere to work on it   

At least it's not just a problem with mine from what I read and hear when out and about. 

JohnM20

I seem to remember that 20+ years ago it was a frequent problem and I believe Alko produced a remedy instruction sheet that involved putting a saw cut across the brake pad at a specific point. We had squealing brakes on a Swift at the time but sold the caravan before I got around to trying Alko's cure. I hope my memory has not totally failed me!!