Drum to disc upgrade worth it?

DefenderWillV8 · Apr 1, 2021

Evening all,

I'm looking for feedback from anyone who has upgraded from rear drums to rear discs. What were the major differences, if any?

The brakes on my vehicle have always locked up on the front under heavy braking, or even moderate braking on wet/slippery roads. I always put this down the drums on the back being less efficient and it's this characteristic that I'm hoping to change.

Thanks

lynall · Apr 1, 2021

Tbh I think most people do it purely because drums can be a pita to look after.
I would not activilty do the mod, but if a cheap axle came up then I might have been tempted.

I think you will find fronts locking before rears is quite normal regardless of rear axle set up.

Rougharse Racing · Apr 1, 2021

The brakes are designed to prevent the rears locking up. Everything since 1980 should have a pressure reducing valve in the rear brake line, it is dangerous if the back end locks up.

tottot · Apr 1, 2021

As above if the rear brakes lock up the back end will not be under control and a sideways slide will start. [ slam on while on wet grass and see what happens ] Disc or drum rears should not lock up.

flat · Apr 2, 2021

Have you adjusted your rears recently? It may also be that they are out of adjustment and doing nothing

v8250 · Apr 2, 2021

@DefenderWillV8 , by all means change rear axle/brake drums to discs. But the question you should be asking is, why? Drums are very simple devices and work very, very well. Most people "believe..." they need to change from drums to discs for better braking, this is nonsense. Really, it's because most owners can't be arsed with adjusting their drums once a year

If you want firmer rear brakes, don't. If you want more effective rear brakes give the rears a clean up, service, pop in some new shoes [Mintex 1144 and/or 1155 is very good] and adjust correctly.

kermit_rr · Apr 2, 2021

Changing the rear brake setup won't stop the front from locking up.
Are your brakes well maintained all round? What tyres are you running and are they at the correct pressure?
Are you simply braking too aggressively?

DefenderWillV8 · Apr 2, 2021

Thanks all for the feedback. You've convinced me that well maintained and adjusted drums can be just as good as discs so I won't go to the hassle of changing. Also the point about not wanting the rears to lock is very logical - I hadn't really thought about it like that before.

A bit of context: The vehicle has been off the road for around 10 years and I've just started a full rebuild with galv chassis and bulkhead as the originals were both shot. Before I refurb the existing axles to get the chassis rolling, I just wanted to check it wasn't worth getting a disc braked axle instead. I was a young man when I last drove it frequently, on wet country lanes, probably a bit too fast, on skinny mud tyres. Latterly, just before it went off the road, I put on some wider tyres and it did make a significant difference to grip under braking. I plan to maintain it much more thoroughly post-rebuild, will use A/T tyres, and I don't drive as fast now, so I'm sure the drums will be adequate for my needs.

Thanks again.

zeaphod · Apr 3, 2021

I think it's worth adding that in my experience of off roading, drums take longer to dry out than discs after wading. If you are rebuilding this with an eye to doing lots of wading, I would go for a disc conversion. I have been caught out in a series in the past after an off road day with lots of wading. Otherwise, drums are fine when set up correctly.

kermit_rr · Apr 3, 2021

zeaphod said:
I think it's worth adding that in my experience of off roading, drums take longer to dry out than discs after wading. If you are rebuilding this with an eye to doing lots of wading, I would go for a disc conversion. I have been caught out in a series in the past after an off road day with lots of wading. Otherwise, drums are fine when set up correctly.

That's why you apply your brakes afterwards, to clear the water out

Marmaduke · Apr 3, 2021

Are we talking 90 or 110? Personally I hate drums and even changed the handbrake on my 90 to a disc...

zeaphod · Apr 8, 2021

kermit_rr said:
That's why you apply your brakes afterwards, to clear the water out

I know, and I did. It took a few miles before they were anything like normal, and in the end I had to take the drums off to get all the silt washed out.

tottot · Apr 8, 2021

When I had a series 2a on the road and was doing a fair bit of off road work and play I drilled out the small drain holes in the drums to 1/4 inch which helped them clear.

sidewinder · Apr 23, 2023

Apologies for responding to an old thread.

Can I ask others for their opinion on which is best for a vehicle that is only occasionally used. I'm swaying towards drums, for the following reasons,
1. As discussed above they are reasonably effective and seem to do fine.
2. The big plus for me is that they don't seem to bind and cause brake judder the way that disks do when sat for a while with the pads rusting to the disks.

I'd appreciate others thoughts.

S

sidewinder · Apr 23, 2023

sidewinder said:
Apologies for responding to an old thread.

Can I ask others for their opinion on which is best for a vehicle that is only occasionally used. I'm swaying towards drums, for the following reasons,
1. As discussed above they are reasonably effective and seem to do fine.
2. The big plus for me is that they don't seem to bind and cause brake judder the way that disks do when sat for a while with the pads rusting to the disks.

I'd appreciate others thoughts.

S

Ps it's a 90

v8250 · Apr 23, 2023

Both are equally good in their own ways. When drums lock on due to rust it can be a challenge to free them up as there's more shoe to drum contact area than with discs & pads. Many folk don't like drums as they do require adjusting from time to time, whereas discs need no adjustment. Neither drums nor discs should cause a judder, if they do it's because they're poorly set up...similarly, both drums and discs can warp, be out of shape, cause vibration and poor braking efficiency.

I have original rear drum set up on the Ninety, albeit with complete new components and Mintex 1144 shoes, with 110 discs and callipers on the front and they work superbly. Although both drums are perfectly balanced/set-up, the rear left drum has been known to lock up under extreme braking which makes for a lively moment. Only had this happen once, on the motorway at 75mph when I had to emergency brake due to idiots in front of me.

I you only use the 90/Ninety infrequently I'd be inclined to keep the drum set-up and save your money for good maintenance/serving and spare parts. In fact, why not put some of these saved ££££'s into overhauling the rear drum brakes??

Turboman · Apr 23, 2023

sidewinder said:
Apologies for responding to an old thread.

Can I ask others for their opinion on which is best for a vehicle that is only occasionally used. I'm swaying towards drums, for the following reasons,
1. As discussed above they are reasonably effective and seem to do fine.
2. The big plus for me is that they don't seem to bind and cause brake judder the way that disks do when sat for a while with the pads rusting to the disks.

I'd appreciate others thoughts.

S

Never had a problem with the rear drum brakes on my Ninety, or on the many Series I have owned.

The pads on disc brakes can rust solid onto the discs if the vehicle is left unused for a long time as well.

Whatever the brakes, the best answer is not to leave the vehicle unused for a long time.

Drum to disc upgrade worth it?

DefenderWillV8

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lynall

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Rougharse Racing

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tottot

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flat

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v8250

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kermit_rr

Very

DefenderWillV8

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zeaphod

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kermit_rr

Very

Marmaduke

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zeaphod

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tottot

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sidewinder

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sidewinder

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v8250

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Turboman

Mab An Gov

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