Air brake adjustment

Was talking to an old truckie last week and he was telling me about a problem with dust getting into brake chambers. It seems that when trailers are operated on dirt roads there is a gradual build up of dust in the exhaust part of the chamber. IE every time the brakes are applied then released the dusty air comes back in the chamber. When moisture gets into the dust it sets hard limiting the amount of travel.
Anyone else come across this problem?

Hi atkipete, we maintain vehicles in the Cooper Basin (Moomba) I have seen this a couple of times but with the conditions they operate in I'm suprised we don't see it more often, the dust storms here are unreal.

I work in a lot of water truck wasers ect and they get a build up of crud on the non air side
I am finding that quite a few brands rust out even
before you replace a diaphram latley. That's why they are still around 60 to 80 bucks ea. quality is going down.
Mark

I hadn't thought about water but apparently the crud can build up to the point where the brakes will not give full travel and give up easily on a downhill run.

It used to happen on the older types, but the diaphram soon got a hole in it and you had to replace it anyway.
The old adage back then was, so what if ones a dead 'un, just plug the air with a handy sized bolt, so no more air leaks or damage occurs and change it when you get back home.

None too sure on what the new ones are like though.



greenie [smiley=vrolijk_1.gif]

If You run a Older Mack they are oil lubricated anyway

We have five agi's, generally we seem to get @ 18 months out of our boosters if we're lucky. But with an agi, you have to remember you could be in and out of the truck 20 times per load!
We use 30/30 boosters throughout, and 9 times out of 10 it's the spring broken in them, rarely a diaphram leak.
Water too is a problem, hosing them off every load obviously doesn't help.

What do you use to wash the trucks , is it some sort of acid?

When you let the brakes off on a trailer the air is dumped at the relay valve (usually located between the boosters) so the air is blowing out, unless the relay/dump valve is jammed open in which case the service brakes won't work (but the springs can still come on). If dust is getting in the (non air side of) diaphrams it is past the pushrod seal. Some boosters are set up so the push rods go up (rather than down!) and hence are more likely to get dust and shite in. For this reason it is a good idea to make the effort and locate the boosters high up above the axle and pushing down.

We try to avoid using acid, however there are times when we do - although it's not like the old hydrochloric stuff, a more user friendly diluted / enviro friendly cleaner. Still stings a bit though!
We use a hot water Karcher most days on the trucks, so combine all this stuff, and the boosters don't stand much of a chance hey?