Disks or drums?

UK PROFESSIONAL DRIVERS FORUMS OWNER AND FLEET OPERATORS FORUM (INTERACTIVE)
1

Simple really… What do you prefer?

2

simple really, if its getting used everyday then disks, if its going to stand about pretty regularly then drums

3

Some one elses trl, disc.
If im paying for repairs, drum.

4

i have researched this a bit, basically all the big fleets are going back to drums, cos disc are better braking, but when they go wrong its normally a tow in job, with drums they normally get home or get sorted at service, also a few have had pg9 for cracked discs, and had no ide…

5

tractor unit, discs

trailers, drums

6

shuttlespanker:
tractor unit, discs

trailers, drums

Agreed,

Our garage manager tried discs but reckons modern drum systems are just as good and a lot cheaper overall.

W

7

I think this thread is similar to the ones that used to be heard in transport offices all over the country.

Air or Steel springs, most customers would laugh if the salesman tried to sell him something with leaf springs these days.

8

AlexWignall:

shuttlespanker:
tractor unit, discs

trailers, drums

Agreed,

Our garage manager tried discs but reckons modern drum systems are just as good and a lot cheaper overall.

W

Yes agreed, i thought this wa about trls only, but with units discs…

9

Never had problems with discs on landfill work and I can’t think of a tougher enviroment. Most people I know who have had troublesome discs are ones who have trailers sitting parked for long periods.
All in all merc axles seen the best on discs and I notice a lot of traders use this as a selling point.

10

kr79:
Never had problems with discs on landfill work and I can’t think of a tougher enviroment. Most people I know who have had troublesome discs are ones who have trailers sitting parked for long periods.
All in all merc axles seen the best on discs and I notice a lot of traders use this as a selling point.

I agree (though I don’t do landfill) disks are the way to go, have only bought trailers with disks for past 10 years, though I do have older trailers still with drums.
For consistent brake performance from new to worn you can’t beat a disk brake, try doing a laden test on a new drum braked trailer and then do one a year later, see how the performance has degraded.

Also agree on the point about parking trailers up for months on end - things can seize up. If its a trailer you need but only use once in a blue moon, stick to drums

11

The main problems with discs come from floating calipers when the pins sieze up, resulting in the outboard pads not being able to back off fully after the brakes have been applied. This causes discs to over heat and the outer skin of vented discs to crack, and can place an enourmous amount of strain on the wheel bearing, as when the caliper eventually siezes solid only the inside pads do any work and they push the hub outwards against the wheel bearing.

I’ve dismantled a few siezed calipers and there is a big design fault. The top pin has a gaiter or boot fitted, and as long as the gaiter is water tight then the top pin is always in good condition and is still bathed grease and moves easily. Unfortunately the bottom pin is open to the elements exposed to salt, road crud and anything else, and suffers the corrosion and erosion resulting in its problems, made worse for anything that regularly gets parked for long periods.

Its a well known problem that should have been sorted years ago, but on a truck the dealer will want to chuck a new caliper on at £400? plus 2 hours labour :open_mouth: , a nice little earner :unamused: .
New seal and slider kits are available for £70 from the fleet factors,

a couple of hours work with the right tools and jobs a good-un. Or just extract the bottom pin (some heat, 14mm allen key socket, gritted teeth, big hammer, more gritted teeth, even bigger hammer) and then clean it up on a lathe, liberal coating of high tempreture grease on the pin and the bush, re-assemble, 1-2 hours :sunglasses:

12

To test for siezed calipers:
Build up air to full pressure, chock wheels and release handbrake. Now get underneath and get a good hold of the air chamber on each caliper and give it a good push and pull in the vertical. If you can feel a healthy thud or knock, its a good-un :sunglasses: If its unmovable then chances are its pin(s) is/are solid :frowning: . If visual inspection of the pads shows any uneven wear, get the spanners out :neutral_face: