4WD fail

[Samblers]

Took the deefer out with a few Prados today up to Wedge. Only my second trip. Sand was very soft, needed a boat in places, and I managed to navigate one particularly troublesome stretch...

















... with the handbrake on :blush:

No wonder it was so hard going, the smell was horrendous (same smell as burning clutch), I hope i havent cooked anything. Any thoughts?

Yes, i'm a numpty :bangin:

[Disco Muppet]

Probably not, can't hurt to get it checked out.
Only likely damage (AFAIK, by no means an expert) is a bit of premature brake wear.

[mools]

No there should be no real damage short of having worn down the pads a bit. I wouldn't worry.

On the other front, I was on a trip out today struggling (not to get) up a **** ant little hill that a freelancer drove up. Then I realised, I hadn't engaged the CDL.

What an arse.

Ian.

[Slunnie]

Does the handbrake still work. I think they wear really quickly if used like that.

[Samblers]

Yeah still works fine thankfully. Is there something that I can (easily) visually check?

I have no idea how the handbrake works on these things...

[Nomad9]

Hi Samblers,
Did you go up to Wedger with a 4WD club or was it just a group of you in a convoy? By the way the handbrake in the shape of a brake drum on the back of your transfer case, doubt you will have done any serious damage, especially if the hand brake works ok now. More worry about the heat transfer into other parts like the propshaft, usually better to run the vehicle after you ahve found the problem rather than stopping and letting the handbrake drum cool. If the brake drum is spinning freely it will cool quicker, standing still the residual heat sinks into other components. Hardens grease ad can cause coking of lube oil if extreme temperatures are reached.
You'll usually see a brown burnt paint stain around the outside of the drum when it has been overheated.
Catch ya.

[JDNSW]

Yeah still works fine thankfully. Is there something that I can (easily) visually check?

I have no idea how the handbrake works on these things...

Nothing easy to see, except perhaps to look for burnt paint on the handbrake drum (on the back of the transfer case)., but this won't really tell you anything except that it got hot. If it works, there will be no serious damage. May need adjustment.

John

[superquag]

Sounds like more damage done to the pride than brake pads...:p:p:p

[87County]

don't feel bad - it's easy to do in eagerness to get going - particularly if your warning light isn't working (the lead can detach from the switch at the base of the lever)

[Samblers]

I was up at wedge with a little convoy of other friends... not a club, just keen blokes and their little offspring :)

Anyway, great knowledge on here as usual - paint is peeling off the transfer case drum so it mustve got hot... its very shortly going in for 60k service so shall request a change of transfer case oil and inspection of the drum.

Yeah the warning light was working OK but... well.... that dazzling West Australian sun and that sparkling beach :cool:

[BilboBoggles]

You may have actually done it some good! Seriously there is nothing like a bit of brake smoking to burn off glazed linings or the oil in oil soaked pads.

[Yorkshire_Jon]

Anyone who says they've never done this before is lying! Welcome to the club:)

I'd guess that you will have cooked the rear oil seal behind the handbrake. Don't be surprised if you begin to see traces of oil appear on the handbrake backing plate over the coming month(s).

Good news is its an easy to get to & quick repair.

You may also want to check if the hand brake light works... (Nothing to do with driving with it on!!)

One way to avoid this in the future is to take off the crappy rover brake and replace it with an X-Eng unit out I the UK... When that baby's on, you won't be going anywhere!

Jon

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[460cixy]

IDE pull the drum and have a sticky beak if it gets hot enough the linings can part company with the shows but if all is well just hose the brake dust out let it dry whack the drum back and adjust it job done.

A properly serviced and adjusted drum type park brake is more then capable of holding the vehicle more so then a disc type the drum type is self energising so the shoes tend to wrap in to the drum under load

"Self-applying characteristic

Drum brakes have a natural "self-applying" characteristic, better known as "self-energizing." [1] The rotation of the drum can drag either one or both of the shoes into the friction surface, causing the brakes to bite harder, which increases the force holding them together. This increases the stopping power without any additional effort being expended by the driver, but it does make it harder for the driver to modulate the brake's sensitivity. It also makes the brake more sensitive to brake fade, as a decrease in brake friction also reduces the amount of brake assist.
Disc brakes exhibit no self-applying effect because the hydraulic pressure acting on the pads is perpendicular to the direction of rotation of the disc.[1] Disc brake systems usually have servo assistance ("Brake Booster") to lessen the driver's pedal effort, but some disc braked cars (notably race cars) and smaller brakes for motorcycles, etc., do not need to use servos.[1]
Note: In most designs, the "self-applying" effect only occurs on one shoe. While this shoe is further forced into the drum surface by a moment due to friction, the opposite effect is happening on the other shoe. The friction force is trying to rotate it away from the drum. The forces are different on each brake shoe resulting in one shoe wearing faster. It is possible to design a two-shoe drum brake where both shoes are self-applying (having separate actuators and pivoted at opposite ends), but these are very uncommon in practice."



And for the members that feel they have to knock every thing I post as made up rubbish the source for the above quote Drum brake - Wikipedia, the free encyclopedia

[roobar_and_custard]

Land Rover drum brakes are an engineering marvel. They never work when you want them to and they never work when you don't want them to.
The only benefit I found for them was driving through the UK in winter in a soft top Series 1 with the roof off. Driving with the handbrake on provides a surprisingly pleasant amount of cabin warming with no noticeable reduction in performance...
Seriously, brakes shoes wear, transfer case seals leak and prop shafts UJs run out of grease. Normal regular maintainence will find this issues - no need to panic...
Ian

[Samblers]

Thanks for all input, much appreciated... will keep my eye on things down there

Audible warning would be good (car moving with handbrake on)!

[Sitec]

We've all done it. The light works on mine.... With the handbrake half on!! No light with it off or fully on!! Thing is, it's dark under there so I've not got to the bottom of the problem. You'd have been in low box powering through the sand, so only running fairly slowly. It gets more exciting when you do it down a freeway at 110kph, stop to 'find the cause of the burning smell' and discover this glowing red frizby under your truck!! :D That's when you melt shoe glue, output shaft seals etc etc. you should be fine!

[DEFENDERZOOK]

IDE pull the drum and have a sticky beak if it gets hot enough the linings can part company with the shows but if all is well just hose the brake dust out let it dry whack the drum back and adjust it job done.

A properly serviced and adjusted drum type park brake is more then capable of holding the vehicle more so then a disc type the drum type is self energising so the shoes tend to wrap in to the drum under load

"Self-applying characteristic

Drum brakes have a natural "self-applying" characteristic, better known as "self-energizing." [1] The rotation of the drum can drag either one or both of the shoes into the friction surface, causing the brakes to bite harder, which increases the force holding them together. This increases the stopping power without any additional effort being expended by the driver, but it does make it harder for the driver to modulate the brake's sensitivity. It also makes the brake more sensitive to brake fade, as a decrease in brake friction also reduces the amount of brake assist.
Disc brakes exhibit no self-applying effect because the hydraulic pressure acting on the pads is perpendicular to the direction of rotation of the disc.[1] Disc brake systems usually have servo assistance ("Brake Booster") to lessen the driver's pedal effort, but some disc braked cars (notably race cars) and smaller brakes for motorcycles, etc., do not need to use servos.[1]
Note: In most designs, the "self-applying" effect only occurs on one shoe. While this shoe is further forced into the drum surface by a moment due to friction, the opposite effect is happening on the other shoe. The friction force is trying to rotate it away from the drum. The forces are different on each brake shoe resulting in one shoe wearing faster. It is possible to design a two-shoe drum brake where both shoes are self-applying (having separate actuators and pivoted at opposite ends), but these are very uncommon in practice."



And for the members that feel they have to knock every thing I post as made up rubbish the source for the above quote Drum brake - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Drum_brake)


what you say is all true and correct........i can vouch for you.......

[Yorkshire_Jon]

A properly serviced and adjusted drum type park brake is more then capable of holding the vehicle more so then a disc type the drum type is self energising so the shoes tend to wrap in to the drum under load...


The issue here is reliability. Yes, the standard handbrake is capable of holding a vehicle, just not a fully laiden one on a steep incline...

I've been dicking around with these things for close to 20years, they will do the job when you go to park up in Woolies car park, but do not cut the mustard when your out and about. They cake up with mud, they regularly need adjusting and even then they can't lock the thing up solid in conditions as noted above.

No, the standard LR drum brake is nowhere near as capable of a disc handbrake. To make that comment is senseless and shows inexperience. Sorry, it just is/does.

Jon

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[460cixy]

A disc brake type park brake can not hold as well as a drum it's as simple as that they don't have even close to the same surface area to begin with. As for mud and crap getting in there. Yes they do need maintaining but so does everything else on the vehicle it's not a set and forget device

[ajge]

The issue here is reliability. Yes, the standard handbrake is capable of holding a vehicle, just not a fully laiden one on a steep incline...



I cant comment on a disk hand brake because I have never owned a car with one. But to say the standard LR transmission brake will not hold a fully laden vehicle on a steep hill is rubbish. I have done this in my 130 (with a well maintained and adjusted transmission brake) many many times. I mean steep and fully loaded. :)
regards
Andrew

[mools]

A disc brake type park brake can not hold as well as a drum it's as simple as that they don't have even close to the same surface area to begin with.

So why did disc brakes supersede drum brakes for the purpose of stopping a vehicle? All things equal if stopping power is simply down to contact area then drums should out perform disks every time shouldn't they? Or am I missing something?

Ian.

[rick130]

The issue here is reliability. Yes, the standard handbrake is capable of holding a vehicle, just not a fully laiden one on a steep incline...

I've been dicking around with these things for close to 20years, they will do the job when you go to park up in Woolies car park, but do not cut the mustard when your out and about. They cake up with mud, they regularly need adjusting and even then they can't lock the thing up solid in conditions as noted above.

No, the standard LR drum brake is nowhere near as capable of a disc handbrake. To make that comment is senseless and shows inexperience. Sorry, it just is/does.

Jon

Sent using Forum Runner


A disc brake type park brake can not hold as well as a drum it's as simple as that they don't have even close to the same surface area to begin with. As for mud and crap getting in there. Yes they do need maintaining but so does everything else on the vehicle it's not a set and forget device

I know Si/X-Eng's disc handbrake is really popular on lr4x4 and i understand why, but we don't have the perpetual gloop/mud problems (sorry Northern NSW/Qld :angel:) that the UK does, and as 460 quoted, the beauty of a drum brake is that it's self energising, discs aren't, so you need more mechanical advantage for the same applied with force with a disc.

There was a run on X-Eng handbrakes here on AULRO a few years back, but I think a few of the fella's found their limitations.

Me, I'm happy with a drum handbrake for the reasons above.

[Mick_Marsh]

Are the park brakes supposed to work? That's a new one.
I just nose up to a solid tree. The thin ones tend to develop a bit of a lean.

[BigJon]

So why did disc brakes supersede drum brakes for the purpose of stopping a vehicle? All things equal if stopping power is simply down to contact area then drums should out perform disks every time shouldn't they? Or am I missing something?

Ian.

Discs brakes don't fade as badly as drums, are easier to maintain and are self adjusting.