Trailer drum brakes on 17.5" whhels

Started with a new company and they are running race trailers on 17.5" rims.
First time I’ve dealt with them and one trailer has just had a full set and the others seem low to me, so wondering if this is lack of maintenance by my predecessor, which seems likely when you see the states of the vans and mini buses or do they wear really fast , so have a few questions.

How low can the shoes wear before needing replacing?
Do you change shoes and drums each time or something like 2 sets of shoes with 1 drum?
I know it a how long is a piece of string question, but how many miles out of a set of brakes?

I can only really answer in more general terms, but I do know that the smaller the wheelsize the hotter everything gets and the shorter life it has. So, assuming that there is no O licence and hence no maintenance records to consult, are there any invoices you can access to give you an idea of past expectancy? So how old are these trailers and what running gear are we talking about? Are these trailers fully skirted which would mean everything gets hotter still? Can you check drum temperature with an ifra red thermometer? Do these trailers have Haldex Info Centre or equivalent you can access? What (axle) weight are these running at? This should give some indication of how hard the brakes are working.

Apart from that either wind off the brakes and have a look if needed removing the backplates or pull a drum off and have a look. You can always ring the local parts factor and enquire how thick the linings are supposed to be.

At the end of the day it is your head on the block, either the job is done properly or not done at all by you. You already seem to have evidence your predecessor went for an easy life, might that be because he wasn’t allowed to spend the necessary money or was he just plain lazy? the drivers may be able to answer that question.

We got one of these ,it’s a tandem on twins ,there’s no abs suzie it works off the brake light wire iirc ,the brakes are very sharp and do get fairly warm even with me :open_mouth: ,I can feel them dragging me back which is how I like them tbh .

cav551:
I can only really answer in more general terms, but I do know that the smaller the wheelsize the hotter everything gets and the shorter life it has. So, assuming that there is no O licence and hence no maintenance records to consult, are there any invoices you can access to give you an idea of past expectancy? So how old are these trailers and what running gear are we talking about? Are these trailers fully skirted which would mean everything gets hotter still? Can you check drum temperature with an ifra red thermometer? Do these trailers have Haldex Info Centre or equivalent you can access? What (axle) weight are these running at? This should give some indication of how hard the brakes are working.

Apart from that either wind off the brakes and have a look if needed removing the backplates or pull a drum off and have a look. You can always ring the local parts factor and enquire how thick the linings are supposed to be.

At the end of the day it is your head on the block, either the job is done properly or not done at all by you. You already seem to have evidence your predecessor went for an easy life, might that be because he wasn’t allowed to spend the necessary money or was he just plain lazy? the drivers may be able to answer that question.

Thanks Cav, to clarify some points your post made.

The wheels are fully skirted and because of the nature of race trailers, lightly load office at the front and heavy stuff at the back, the axles do tend to be near their max, and the trucks have exhaust brakes, but no proper retarder. 2 of the 3 have some system kind of info system.

They have been running under an O’licence, (restricted) but the operation has moved from one part of the Country to another, so they have a new O’licence,

The person who was acting as TM left some time ago and somebody with no background in transport was given the task, so what with their lack of knowledge and disruption of moving, the paperwork is problematic to say the least. I have inspection sheets and invoices for this year and some stuff from further back, but they are incomplete.

Talking to the bloke who drives one of the other trucks and one of the only members of staff to move with the company, he reckons that the original TM tried to keep maintenance to a minimum and didn’t get damage repaired in an attempt to impress the boss as to his cost saving abilities.

My attitude on this type of operation is you need to possibly go a bit OTT with maintenance, as a breakdown in parts of Europe can be far more costly and inconvenient than replacing a part early when at home, as well as the image side of having vehicles with scrapes and dents left un-repaired.

We now have a new O’licence and new maintenance provider, who seem ok, I’m confident they are making sure the trucks are safe, but we are getting some pretty big bills and I’m trying to work out if they’re doing more than they need or catching up on what should have been done before.

The little drum brakes are pants, bpw okay saf nightmare
We used to see a few low loaders with them and almost every service there was something wrong on the brakes.
Cam/bush wear is also an issue, use a dial gauge to measure lift close to each bush, you might assume they are visually fubared when in fact they are within the 0.8mm wear limit.
If you have rear steers snapped slack adjusters is another common thing for some reason?
Where I am now we have 4 double deckers on little wheels with a mix of saf and bpw, they have caused so many issues over the years they are on a 6 week service interval, the rest of the trailer fleet is 12 weeks.
If the shoes are genuine they will have wear marks on the side, if not I wouldnt let them go below 6/7mm overall lining remaining and even then you may still get issues with the shoes going over cam especially if the drums are worn.
If you speak to your parts supplier they will be able to get you the wear limit on the drums.

A wise eman would tear them down after every mot and check/measure and go from there.

In my early days on car transporters the drag part of the wag drag was on silly little wheels, might even have been 16".
I used to adjust my own brakes up in those days and if you had a heavy workload they could go from fully adjusted to being at the very end of adjustment in a fortnight, they ran fairly cool though due to skeletal body, i could adjust them from the open chassis above.

Lots of instances of brakes going over the cam, several fires due to this, the in house garage (messrs Bodgit and Scarper) would do nothing till the vehicle actually broke, i once mentioned service and they looked at me like i had three heads :unamused:

As the general consensus above, these things need a lot of regular attention.

Much of it is down to the driver, we had to race around on that job to make any money, but your lads should be able to keep braking to an absolute minimum given they do at least have exhausters, we had sod all other than the barely there brakes.

Looks like I’ll be keeping a close eye in these then, SAF axles as well. :frowning:

muckles:
Looks like I’ll be keeping a close eye in these then, SAF axles as well. :frowning:

If removing the hubs, DO NOT undo the hub nuts otherwise YOU WILL shag the axle threads, drill and split the nut then wind it off, new nuts every time and grease the stub axle when refitting the hub

Oh lefties one side and righties the other

:

Trickydick:

muckles:
Looks like I’ll be keeping a close eye in these then, SAF axles as well. :frowning:

If removing the hubs, DO NOT undo the hub nuts otherwise YOU WILL shag the axle threads, drill and split the nut then wind it off, new nuts every time and grease the stub axle when refitting the hub

Oh lefties one side and righties the other

I don’t get my hands dirty, leave that to the workshop. :wink:

muckles:
:

Trickydick:

muckles:
Looks like I’ll be keeping a close eye in these then, SAF axles as well. :frowning:

If removing the hubs, DO NOT undo the hub nuts otherwise YOU WILL shag the axle threads, drill and split the nut then wind it off, new nuts every time and grease the stub axle when refitting the hub

Oh lefties one side and righties the other

I don’t get my hands dirty, leave that to the workshop. :wink:

Yes but if they dont know and lots of people dont its a costly mistake