(Drum) Brake Squealing.

[Ordo]

Hi all,

Been some time since i last posted to The Samba and i usually only do so, when i tried and failed to fix something. Like my front drum brakes for instance.

I own a '68 Deluxe since 2018 and i have struggled with my front brakes ever since i put it back on the road.
Replaced everything, from backing plates, cylinders, shoes and even drums. And the damn thing still squeals like it's a beaten pig, whenever i stop at a traffic light or any other moment i would have looked cool and stuff in my bus, but end up looking like a complete idiot, because the damn thing sounds like a screaming witch on acid when stopping. (no pigs or witches were hurt in the making of this post)

I know this could be a wide range of things. But except for finally coughing up the funds to upgrade to discs, I'm out of ideas.

I'm going to replace the shoes one more time (even though they're as good as new) and bleed the system one more time. But besides that, I'm out of ideas.

Anyone here have other ideas?

_________________
It does not matter how slow you go, as long as you don't stop

'68 T2A Deluxe
'66 Notchback
'65 Deluxe Beetle

[lil-jinx]

i worked at a shop where when a truck came in with squealing brakes,and no obvious cause,the fix was to go for a drive and ride the brakes to heat them up,it was assumed that dust was causing the squeal and the heat burnt off the dust,I think that the heat altered the state of the shoes ,probably making them softer on the surface ,but whatever the cause ,it stopped the squealing for month or two.
this was on air brake equipped trucks ,so no worries of heating up brake fluid,which may be a concern with hydraulic brake if things get too hot.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=620186
https://www.thesamba.com/vw/forum/viewtopic.php?t=668799
1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy sold dec 2024

1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes.

[busdaddy]

Pull the drums and post some pics of the shoe contact surfaces.
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[raygreenwood]

[OB Bus]

My opinion? You have spent plenty of money "looking cool". Who knows how much you have spent fighting the issue with drums?
Spend the money on something that might make you live a bit longer. And not squeal.
Type_e Motorsports has a marvelous kit to switch to discs. Please consider doing that.
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Larry in OB
Stop dead photo links! Post your photos to The Samba Gallery!
69 Westfalia and 2002 Eurovan Camper.
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[airschooled]

Each drum brake backing plate has a handful of contact pads where the shoes touch and slide along the backing plate. If those spots aren’t clean and SLIGHTLY greased you’re going to have squealing no matter how much money you spend on brake parts.

A little squeak first thing in the morning is ok, normal even if you live where it’s humid. It should go away with a few easy stops.

Robbie
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[SGKent]

also - if the leading edge of a pad or shoe hits the rotor or drum before the trailing edge, it will chatter causing a squeal. One easy fix that works most of the time is take a file and bevel the leading edge of the disc or shoe. It doesn't need to be much - just bevel it over maybe 1/8" at about 30 degrees - the angle is not critical but you want a slope and not a steep angle like a 45. Think if you were pulling a board across the ground. The front edge would dig in, but if you angled the edge so the board slid over the ground it would be easier to pull and it would not dig in.
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"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[lil-jinx]

wheel torque could be a factor.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=620186
https://www.thesamba.com/vw/forum/viewtopic.php?t=668799
1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy sold dec 2024

1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes.

[airschooled]

[lil-jinx]

it could distort the drum,causing stress points in the drum ,which could vibrate at high frequently causing the squeal.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=620186
https://www.thesamba.com/vw/forum/viewtopic.php?t=668799
1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy sold dec 2024

1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes.

[SGKent]

[Ordo]

[Ordo]

[SGKent]

[lil-jinx]

po says he replaced drums,shoes and backing plates ,and it "still"squeals,does this mean that it was squealing before the parts were replaced.if so then i would think that the new parts are not the cause.new parts ,drums often come with a skim of oil on them,new shoes and drums should be cleaned, preferable with brake cleaner,before installing,
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https://www.thesamba.com/vw/forum/viewtopic.php?t=620186
https://www.thesamba.com/vw/forum/viewtopic.php?t=668799
1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy sold dec 2024

1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes.

[raygreenwood]

So, a couple of things:

1. Squeals with brakes are caused about 90% of the time (as SGKENT and a couple of others are getting at) by a high speed vibration of the pad or shoe. This is precisely why they make backing insulation plates and backing/damping anti-squeel adhesive. Disc pads are worse on older cars like ours because you have a square or rectangle....running perpendicular to rotation of the disc and that tends to TRY to start an oscillation at lower clamping pressure.

Brake shoes on drums can suffer from the same problem, they just oscillate in a different direction.
This is why adjustment and the springs, pins and parts must be correct and adjusted to keep the shoe rigidly under tension.
And, the shoe MUST be shaped correctly to the drum. If you have a drum that is worn or turned too much oversized compared to the arc of the shoes, a portion of the shoe can be under supported and vibrate. Or, if the drum surface has taper....the shoe can edge ride and again, unsupported shoe area can vibrate and squeeze.

2. The other 5-10% of the time, it can be a hardness issue. Certain pads and shoes like some racing components with a very high and hard metal and/or ceramic content can squeel. Likewise, if the drum surface is overly hard or brittle because it was heat glazed....it can squeel badly.
Also ....and normally....hideous squeeling at all levels of stopping are a stacked up combination of these items. If the drums got hot and glazed and have some ridges and the pads are kind of the wrong material.....the drums get "grabby" or grippy on the pads (or vice versa) .....and they stick and snap loose in contact with each other very rapidly....causing again....and oscillation that causes the squeeze. You can get this same issue when drums are warped to a degree and have "lumps" in the surface of the friction area.

Another thing to look at. I went to the site where you bought your shoes. It reminds me of a European version of Cip1.

They list A and B quality shoes and a third range of shoes with no letter code but a price tag that can only mean they are "C" level shoes. These are listed as the "Uber" brand which because of the crappy AI assistant just put into Chrome in the last week....I can mainly only find information on for bicycle brake pads for that brand.

The one notation on Uber brand brake pads or shoes I could find....was having "squeeling issues" hmmmmmm

To continue, on the Paruzzi.nl site.....most of the "B" level shoes are listed as "China" with a red tag near the bottom. Most of the "A" shoes are listed as ATE.

So.....what shoes did you buy?

Ray

[lil-jinx]

yes ordo the wheel nuts,not the axle nut,if improperly torqued,too tight too loose or improper torque sequence can warp the drum,and with your wide 5 wheel, the chance of warping increases,as opposed the smaller spacing.
if the axle nut is not properly torqued,then that's a whole different issue.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=620186
https://www.thesamba.com/vw/forum/viewtopic.php?t=668799
1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy sold dec 2024

1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes.

[Ordo]

[KTPhil]

I always chamfer the leading and trailing edges of the shoes. VW used to recommend that. I also sand off any rust on the backing plate bumps, and on the corresponding points on the shoes; then I add the slightest smear of anti-seize paste on the plate.
_________________
Current Fleet:
- '71 Fastback
- '69 Westfalia
Retired:
- '67 Beetle
- '65 Beetle (x2)
- '65 Bus
- '71 Squareback

[lil-jinx]

i was supprise when i first looked a vw bus brakes,with a fixed anchor at the adjuster,and equal size shoes,where most new cars ,before disc brakes took over,had a floating adjuster with a short shoe at the front and a long shoe at the back ,appling the brake caused the front shoe to grab the drum and got rotated down and back putting pressure on the larger rear shoe,increase the pressure by using the rotation motion,requiring much less hydraulic force.
_________________
https://www.thesamba.com/vw/forum/viewtopic.php?t=620186
https://www.thesamba.com/vw/forum/viewtopic.php?t=668799
1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy sold dec 2024

1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes.