Hi, One of our drivers got stoped by Vosa last week and the only thing which they did not like on truck were rusty discs on middle axle- vosa inspector said that the reason they are rusty is because breaks probably do not work properly. They just suggested to check it out. We send the truck to take brake test and it passed. So I was wondering if anyone know how we can polish them so that way they can look presentable - the truck is going to go for mot in 2 months? Thanks,
Bin them.
I wouldn’t bother TBH. Might be down to axle loading based on the loads typically carried. Could be a suspension issue maybe.
Is is a lift axle?
Sometimes with the lift axle ,the issue is that if it is raised then the discs rust because the wheel isnt rotating ,doesnt take long to show signs of rusting ,Have had it where you cant turn the wheel by hand ,though if your lower the axle drive 10 feet it then spins freely …So a good drive with the axle down and a load will sort it out …VOSA man ,probably an ex brickie
Lots of trucks have weak 2nd axle brakes they tend to do very little in comparison with the other two and its not unusual for the middle axle brake pads to last the life of the truck.
I would say they look like they have stood and the pads have stuck to the disc hence the chunks missing.
Cant hurt to pop the wheel off and check pads and calliper slider are free moving.
Brake roller test doesnt always tell you the whole story.
You can get them skimmed,I got them done and flew through the test.
They Look Like They Will Skim As Long As They Aren’t Worn Below The Minimum Thickness. You Will Need To Find An Independent Or Franchise Dealer With A Commercial “Pro-Cut” Machine. Many Moons Ago In A Different Life I Had One And We Used To Skim The Discs Rightly Or Wrongly At Every Pad Change.
Alternatively A Good Run With A Load On Will Clean Most Corrosion From The Face Of The Disc.
If I,ve had a week or 2 in the winter running light with the axle up mine start to rust over , a day with the axle down soon has them looking like new again
I’m with Cav, they’re buggered, if you drop the mid lift and run around all day on the brakes to clean them up all you’ll do is wear out the pads (and give the others a hard time too) and the chunks will still be in there the disc surface.
I agree there buggered, I’ve changed them in the past when they’ve got like that, the face has gone and the bits that look like corrosion are in fact pit marks, seen them go like this when they’ve been really hot
For the price of discs they are not worth skimming in my opinion
Very little brake effort comes from the midlift, not impossible for the original pads to last the whole life of the vehicle. If I changed trailer discs every time they looked like that I’d do little else. I agree not worth skimming but can be worth going over the face with a die grinder a bit but use a brand new clean grinding bit.
Very simple question: if those discs were on your car would you be happy to let your wife drive it with your children in the back?
Nothing wrong with the discs just a bit of “scag” through under use due to loading.
Probably ■■■■ the brake test with a lock out.
As long as they have no long radial cracks there is nothing wrong with them.
put the pads from the front axle onto the mid lift, put new pads on the front axle, and make sure the mid lift is down more and doing some work.
also unless theres been a law change, when a unit with 3 axles is loaded the lift axle needs to be down.
I got stopped a few weeks ago in Belgium.
They noticed that none of the disc breaks were shining.
I told them that i hadn’t used the footbrake for a while, only the engine brake. One of the officers didn’t know what i was talking about.
Eventually had to drive round the parking lot, braking a couple of times with the footbrake just to prove the brakes worked.
When they checked the disc brakes they were shining like a new pin…
We used to do a 4x2 unit on local work which had one rusty disc on the front due to a previously overheated brake. It never really cleaned up through normal use and I pointed it out the tester at MOT. I told him they owner won’t replace the discs because it was only local, he said " we’ll see on the brake rollers, generally rusty discs have better grip". I was a bit surprised at him saying that, it sailed through the brake test and we never did change them.