Getting those Rear Hubs off *&^&*(*

[Darren]

Although I've been pottering in the workshop of late I've had nothing much exciting to report.

But I thought I'd show this ... Been working on my car quite a bit lately and one issue I had was metal on metal grinding on the rear brakes. It's not that long since I put new shoes on, maybe a year. So I didn't rush out and buy new shoes, instead I decided to have a look at what might be going on.

And don't you know it, those bl***y drums would not come off. There was me banging and levering away and would they budge! I'm sure some of you have been there and got the t-shirt. Well I did manage in the end and I was damn well going to make sure I didn't have to go through that again.

I'm sure most of you know what the problem is, it's the lip that forms as the drum surface wears. You have to force this over the shoes and it can sometimes ruin them if you are unfortunate. Mine were ok and as suspected they were not worn either. In fact they still looked new with plenty of meat on them.

So, first job was to remove this damned lip.  
Centered up to within 0.001" on the RT and not only milled the lip off but took it a further 0.020" as well for future wear.



There then, that won't be giving me any more trouble will it  

Now onto the original problem, the metal on metal binding noise. As I said the shoes were fine so we had to look for other signs of trouble. The only thing I could come up with was that as the drum rim had worn slightly allowing the metal part of the shoes to come into contact with the outer face (wheel face) of the drum as this was tapered at the very outer edge towards the rim. (you can breathe now)

So 0.050" was removed



Sorted, did both drums and the brakes no longer make any 'orrible noises and the drums slip on an off without a hammer in sight  

[Bernd]

Darren,

I remember the days I did my VW brakes. Same problem. Only I discovered that as the shoes wore the brakes would adjust themselfs. They had a small star wheel the would turn a nut and extend the brake rod from the cylinder a bit further.

What I had to was take a screw driver and screw the little wheels back in releaseing the brakes. Made taking the drum off much easier. With todays disk brakes no such worry any more.

I've attached a copy from the original VW manual to give you a better idea of what I'm talking about. It's item #7.

Bernd

[Darren]

Yes I know what you are on about Bernd. You could release the brakes through a little hole in the rear.

Mine have an adjuster, but it's in the same place as the hydraulic cylinders and there is no access from the rear.

Hence my modifications to prevent a repeat performance

And they say we are advancing .... 

[AdeV]

And they say we are advancing ....  

Modern cars don't have drum brakes.....  

(as far as I know!)

I had similar issues getting the drums off an old Capri axle; fortunately I didn't have to care what damage I did, so the large adjustment hammer was used  

Good fix, though, I like it 

[CrewCab]

I'm sure some of you have been there and got the t-shirt. 

In 3 sizes ............ and I've also got one showing Bernd's brake adjusters , though in my case they were affixed to a Ford Anglia 

Takes me back a while chaps, thanks for making me feel old 

 

CC

[CrewCab]

PS: ........... Darren .............. nice fix mate .......... wish I'd had a milling machine 30 years ago 

[andyf]

Takes me back a while chaps, thanks for making me feel old 

CC

You feel old? I got my T shirts doing similar repairs on a Jowett Javelin and the Lea-Francis Sports I got as a swap after I married, when having a nice big bench seat in the front was no longer so important.

At least cars were interesting and fixable at the roadside back then. Now, I hardly know where to start on them  .

Andy

[John Hill]

Good work Darren,  yes I have one of those T-shirts too.  My Riley had brakes designed on  Monday morning the day after the works picnic.  Hydaulic brakes on the front and mechanicals on the rear  incorporating the worst features of each system.  The rear brakes hardly worked at all and the front brakes (which actually worked OK)  had twin leading shoes which means very poor braking going backwards,  this city has some very steep streets and I eventually learned to reverse down the steet at mind numbing speeds!

[Darren]

Wotsa Jowett Javelin and the Lea-Francis Sports 

Crikey ... you guys .... my car is a 1997 .... is that old 

I had a very hot Astra that I did many mods to inc totally tuning the engine with no expense spared. That had disk and drums on the back .... weird .. 

[John Hill]

My first car was a 1930 De Soto...

[ieezitin]

Hey guys.

don’t knock yourself too much. I have owned a 1997 ford F150 1/2Ton pick up 4 wheel drive for its entire life. Discs on the front and shoes on the back. Never / never have I replaced the back brakes. Just not worth it. The discs on the front do all the stopping.

All round discs are the way to go for stopping power but these cheesy car manufactures never applied all round discs. only now are companies supplying all round disc brakes.

Drum brakes don’t work. Never have never will.

All the best.              Anthony.

[75Plus]

I had a very hot Astra that I did many mods to inc totally tuning the engine with no expense spared. That had disk and drums on the back .... weird .. 

Disk and drum on the rear is a common practice. The drum is for parking or emergency and the disk is for normal service. Disk brakes don't lend themselves to mechanical operation as drum brakes do. On my two vehicles the drum is only about 8 inches in diameter to allow clearance for the calipers.

Joe

[tinkerer]

They can be a bugger sometimes. I figure you checked the min. thickness allowed and you were good with that. Rear brakes don't stop you, they just keep the backend behind the frontend. A milling machine really opens up the projects you can undertake. One day.

[jatt]

Yes I am very happy my current drive (Falcon ute) has discs all round.  Frotunately I wont have service my trailer brakes too often.

Spent many fustrating hours playing with rear drums on my previous four cars.  Two of which were Mazdas.

Mazda had this damned habit of putting stake nuts (soft metal nuts that u had to belt the end collar over with a chisel).  Take em off once and u stuff the collar up.

Give me split pins any day.

[John Hill]

Yes I am very happy my current drive (Falcon ute) has discs all round. 

How is the hand brake?  My XH has had a useless hand brake from new, and now it has developed a pesky, scraping, scratching, noise in the rear brake.  Oh well, ten years is not new anymore!

[Stilldrillin]

Beating the rear drums off takes me back Darren! I always had Fords....... Cortina, Capri, Escort..... Old ones! 



1968....... I started toolroom turning on nightshift, at a local engineering firm, & quickly found it was my (government) job to skim the other employee`s brake drums......

I also quickly found they had to be mounted on a mandrell, as gripping on the o/d gave a square bore & more judder than the original problem! 

David D

[jatt]

Its probably not what u wanted to hear John, but my XH handbrake is the best one on any car I have owned to date.

Can only assume your rear discs look physically ok.  I'm sure u know ur way around a set of discs, so I wont insult u further.

Only issues I have with mine at present is the overflow bottle has a small crack at the top and theres a small leak somewhere around the exhaust at the engine end.  If I could find a good spot to put an aftermarket bottle (the orginal is over $200 AUD) I would be very happy.

[Darren]

Drum brakes don’t work. Never have never will.

Mine do, if you leave the handbrake on and drive off the car just drags its back wheels. You won't get far though cos you really know about it.
It will not reverse at all, just lifts the back end up and you go no where.

If they didn't work they would not have worn this huge lip  The car is capable of carrying a ton (1000kg) in the back so it needs proper brakes. (actually rated for 900kg)

We still have drums on the back because it's illegal to have hydraulic handbrakes in case you have a weep. That tiny weep could an has caused some serious accidents. I think now some cars have a mechanic cable system to operate the rear parking brake on the disk. The early ones were dreadful I seem to remember.

[AdeV]

Drum brakes are great where braking forces are slight, and holding requirements are high; i.e. they're ideal for handbrakes (e-brakes) and rear brakes in normal road use. Performance cars, or just plain heavy cars, are better off with discs all round, but most (maybe all) will retain a small drum for the handbrake, as Darren mentions. Not sure if that's because a disc handbrake is illegal; but because the holding force of a disc brake is feeble relative to drums; and, if your brakes are hot when you park up & apply the handbrake, as they cool the disc shrinks, the handbrake force gets less & less, and eventually the car rolls off down the hill...

I recall Dad telling me about the first time he drove his mini after fitting disc brakes all round, and sailing out of the first junction he came to because, whilst the discs slowed him from 60 to 10 brilliantly, they just couldn't do the last 10mph...

[Shepherduke]

Darren, a question from a newcomer.  Was there a reason for not doing the job on a lathe?  I know that sometimes a brake drum will not be concentric after a while and ovality is an issue.  Was this the reason?ATB Kevin

[Darren]

Hi Kevin,

I wasn't too worried about concentivity as I was not skimming the braking surface, just removing the lip.

But the drum was simply too large for my lathe. After doing it on the mill it's now very obvious to me that it's a far simpler task to to on the mill. If I was asked to do another smaller drum I would still choose the mill. Easier to set up true for a start.

[Bernd]

Mine have an adjuster, but it's in the same place as the hydraulic cylinders and there is no access from the rear.

I see you guys been busy talking about brakes while I was sleeping, but then again your at least 5 hours ahead of me and you guys down under are ready to go to bed. 

I discovered that to on a new version of VW brakes. What I found was they moved the hole to the brake drum outside. I at first I had no idea why that holes was there. 

[ieezitin]

Darren this is why I said drums don’t stop a vehicle.

Before this explanation, lets get to the  fundamental nature on what we are talking here, it is friction and heat. We have to understand the common philosophy that both systems use when stopping a car in relation to this. On how it absorbs and releases this phenomena.

By applying resistance, or friction, to a turning wheel, a vehicle's brakes cause the wheel to slow down creating heat as a consequence. The rate at which a wheel can be slowed depends on several factors including vehicle weight, braking force and total braking surface area. It also depends heavily on how well a brake arrangement converts wheel movement into heat by way of friction and how quickly this heat is removed from the brake components.

This is where the difference between drum brakes and disc brakes becomes definite.

Under high braking conditions, like descending a steep hill with a heavy load or repeated high-speed slow downs, drum brakes fade and lose effectiveness, drum brakes can only operate as long as they can absorb the heat generated by slowing a vehicle's wheels. Once the brake components themselves become saturated with heat, they lose the ability to stop a vehicle. The shoes glaze and loose all properties for resistance at that moment,  It gets worse with time and ware and in the end the system becomes ineffective.

In the same situation with heavy disc braking, the rotor used in disc brakes is fully exposed to outside air. This exposure works to constantly flood cool air to the rotor, greatly reducing its tendency to overheat or cause fading. This system is ten times more efficient at shredding excessive heat. Another trick is to drill holes in the disc as to trap water which in turn by means of convection vents off-steam accelerating the heat loss process.

Sure cool breaks works fine hence you have full lock up, heat them up and I guarantee you  are only stopping on your front discs.

All the best.                     Anthony.

[Divided he ad]

Nicely done Darren.... I'd have still used a die grinder.... but then that's old habits and all that  


LOL.... Been there done that T shirts and all.... Never made the video though!?  MOT'd, failed and fixed in their hundreds..... got fixes for all your ills!!    

Just not on line enough and not really an easy thing to sort out in text on the interweb!




After reading this thread there are just a few things I'd like to add....


Drum brakes are still fitted to new cars... Mostly small ones, go look at some lower end Clios, Micras and Corsas etc.... Many of then still have em'. They're cheaper than discs and calipers!

Also I usually find adjusting through the stud hole with a home made gadget works very well  






Ralph.

[John Hill]

Its probably not what u wanted to hear John, but my XH handbrake is the best one on any car I have owned to date.

Maybe those boys at Geelong left something out of mine as it has been very poor from new!

Only issues I have with mine at present is the overflow bottle has a small crack at the top and theres a small leak somewhere around the exhaust at the engine end. 

200,000 coming up on mine and there is quite a list!  The first set of front brakes lasted 60,000 (because I was not using the shifter enough?), the air con had the condensor replaced and 3 years later is leaking somewhere, the fuel system got water in it (that stupid cap on the side?) requiring new tank liner, fuel lines, fuel rail, injectors and fuel pump.  All sorts of electrical things have stopped working, rear window heater, a few dash lights and 3 of the speeds on the fan switch.  It needed a new head gasket too!  But hey, it looks great being Regency Red XR6 with full body kit, hard lid and a nice Aussie style sun visor!

Sometimes I wonder about my sanity in keeping hold of it.

Sorry Darren, hope you do not mind the hijacking of your topic!