Brakes
My brakes occasionally make a juddering clunking noise and don't feel that efficient if I slam them on for whatever reason. With the weather like it is at the moment, I do not need dodgy brakes! They have always done it and I had various bits replaced for MOTs but it has made no difference.
Any ideas?
The brakes probably need a good service, check and adjust but you can try the simple checks below. What bits were replaced for MOTs?
post some images of the discs/drums pads etc to give us an idea of what condition they are in, are you able to measure the disc/drum thickness to guage the wear?
If you are feeling the vibration when braking through the brake pedal it may mean warped brake discs or drums.
If you are getting a shaky steering wheel when driving you may have wheel bearing problem or wheel balance/rim out of shape or bent or even defective tyres
Are the brakes in balance? Does the vehicle pull to the left or right when braking or when coasting? Binding brakes can cause all sorts of issues....including poor braking as the surface of the brake disc or drum can get heavily glazed and the brake pads or shoes can get burnt/overheated and won't grip any more...
Have you replaced the brake fluid recently? Brake fluid is hydroscopic, over time it absorbs moisture and can become unefficient making the brake pedal feel spongy and vague. Brake fluid should be replaced at least every 2 years regardless of use of vehicle or mileage.
The MOT may have passed even if the brakes are unbalanced or weak, 4x4 vehicles are not normally checked on the brake rollers as most MOT test centres on have a 1 axle brake roller tester which means that the the other axle that is not on the rollers is still being driven. The test on 4x4 is normally done by using a TAPLEY or inertia test device, vehicle is driven and brakes applied, only 50% brake efficiency is required to pass the test.
Hope this helps!
evening audiominx, it just sounds like your abs is cutting in ,do you feel a sort of 'crunching/ juddering ' through your brake pedal?
if so that is quite normal as that is the abs pump doing its 'thing' distributing braking force around the wheels realeasing and braking on the wheels that are rotating or locking to allow you to steer while braking on snow /ice /loose surfaces ,ironically the braking distance will be longer in snow with the abs as the wheels will not lock up to form a snow wedge in front of the tyres at low speeds ,only allowing this to happen when the abs drops out at very low speeds.
the main purpose for abs is to give the ability to steer whilst braking at the limit of grip , it is not unusual for a driver who has not felt the unusual sensation through the pedal to release the brakes in panic at the vibration of abs interuption and then crash after ironically mistaking this safety feature as fault.
the abs on a 463 is fairly abrubt and noisy i think that is what you are hearing and feeling ,if in doubt of course have your g checked over.
just seen g singh's comments and of course you could have damaged discs/drums/linings/abs rings but your comments have come just as the conditions on the roads come right for abs activation on every journey.
yes they are very good in the snow, i have just put my tyre chains on at 11pm last night as iam going out this morning to maybe pickup or rescue a friend who is working for local tv and got stranded with his crew last night on the mendip hills above where we live ,we have some horses to muck out /feed up on top on some land of ours to visit also so its time to 'chain up' as it looks pretty 'knarly' up there as we saw last night on the local news / drive around with people attempting the impossible in normal cars ,the g is good, but i just cannot stop and tow them all! i will post some pictures from the mendips if we see any thing of interest , my 460 has no abs so you have to really careful in 4x4 as the front discs put their braking effort to the rears also which along with the braking from the drums makes it really easy to lock it up /so gentle braking is the order of the day as jumping on them is a bad idea as you can spin the whole rig in the blink of an eye , just looked outside we have had over 12'' and it is drifting up top of the hills -glad i put the chains on last night -they are high quality german made items from rudd chains in kent i have used them in austria alot and they are superb with extra h/d construction and take alot of abuse and my goodness they give you some bite you can just leave it in 2 wd and it stops on a dime even on ice -very reassuring as we nearly had it slide away down a steep hill last night on packed ice/snow and we just came down in 1st low under control but if you tried to hold ,it was gently sliding all on its own and even with all the diffs locked would not back up ( very nasty conditions) wet snow packing instantly under the tyres converting straight to ice . even a g needs its chains to operate in these conditions unless you go full winter tyres, but for the ultimate you cannot beat chains, i used to drive a cat 980 loading shovel in a quarry and an axle set of tyre protection chains weighed as much a swb g wagen.
Hello Audiominx,
I am going to presume that your ABS light did not come on with you felt the brake jittering. The jitters, as I would describe it, come on a light brake application and the brakes do not feel balanced. The brake force unbiased floats from one side to the other side where it seems may have a need to correct your steering.
Further accompanying symptoms may be, upon releasing your handbrake, the rear brakes do not immediately release, instead, they 'snap' to a release as your take up drive. Should that occur, I suspect you have contaminated rear brake shoes with some accumulation of brake dust and probably a lightly leaking rear hub seal leak.
Easiest to check is the colour of the brake fluid in the brake reservoir. Should the colour show darkness or is black, it is likely the brake fluid is overdue its scheduled renewal. Note: blackness, regardless of brake fluid renewal remains in the reservoir bottle renewal so it would be more accurate to see the fluid undoing the reservoir cap and remove the fine gauze filter, if fitted, to check the brake fluid colour. Fresh brake fluid is light amber to a slightly dark shade of amber and absolutely clear. Contaminated fluid is much darker and may have black residue floating in it. The point being is you should know what the norm is, to make comparisons of the fluid in order to evaluate.
Your local garage should be able to test the fluid for you, should they have the equipment to do so; it takes some three to five minutes only. So, should your fluid be dark brake fluid, renewal is in order of the day. Labour charge should be half an hour if the wheels have been removed as for say, in an Inspection service, otherwise, upto an hours' labour if you specifically ask for a brake fluid renewal. Brake fluid, no more than 1.5 Lts consumed.
Moving onto the rear brakes; these do need to be cleaned of brake dust and the drum surface de-glazing, properly adjusted. Should there be a light contamination of oil from a leaking oil hub seal; depending upon the level of leak, this can be cleaned out with brake cleaner and refitted. Under the rear axle tube at a six O'clock position is a small drain hole, ensure this is unblocked to allow for leaking oil from the hub seal to drain out without contaminating the brake shoe. Do check the rear diff oil level, replenish as necessary and have the level checked every 6,000 miles and inspect the brake shoe for further contamination. In order to renew the rear hub seals, you are looking at the renewal of the rear wheel bearings (£60 - £80 per side at my last count, not sure of current price and 1.5 hrs Labour per side).
I have sent you the finally finished article on handbrake, which is awaiting posting on the forum when they have sorted out their new server.
Get the front brakes checked for piston freeness and pad freeness, have the pads cleaned or renewed as necessary and the discs de-glazed.
If the fault remains then, have the ABS sensor wires and, or connections checked out. If it is apparent the sensor tips or the dirty, these could be cleaned out if they withdraw easily, sometimes with dirt contamination these can be difficult to extract and may end being destroyed (wires are some £80 each) upon removal.
In the extremes the driveshaft ring gear(s) could have cracked or the ECU is or its connections could be faulty. The conditions are rare but a possibility.
There are relays and ABS motor to consider but we can come to those latter.
I vote ABS. To a man with a hammer everything looks like a nail :-)
IanA2,
Like your quote, so what would a man with a screw driver ..........(censored)
....an opportunity to fix a floorboard.....?
How ever did you guess that! Ha,Ha..
I think on your model 463 you have a button to turn off ABS, turn it off and see if brakes feel the same, ie one or more wheels may lock up. You will get a warning triangle appear in instrument cluster to tell you ABS is disabled. Same as when you engage centre dif lock.
This weather is excellent for testing the ABS. On an empty slippery supermarket car park brake really hard. If the ABS is working, nothing will happen in the slowing down department, and you will be able to steer to avoid the trolleys. If the ABS is not working, nothing will happen in the slowing down department and you won't be able to steer to avoid the trolleys. The crunching noise as you go over the trolleys is a really obvious indication of a fault in the ABS system. Tesco trolleys makes the nicest noise, but Aldi trolleys go flatter.
Perhaps it would be better if you followed Rakesh's advice after all.
Fair point, well made! I think that maybe Rakesh is the better option. No offence.though
If the weather is that bad that you're getting the ABS working frequently then you would have more control of the vehicle if you had the centre diff locked. This turns off the ABS anyway.
JOIN THE GWOA
This website and forum are provided for the benefit of enthusiasts and owners of all Mercedes Benz off road vehicles, in particular the G Wagen. The costs of development, upkeep and provision of the site are met entirely by the annual subscriptions of club members. If you are using the site and are not a member of the G Wagen Owners Association please consider joining. You will have access to areas on the site that are not open to non members, to club trips and meetings and to technical assistance. In addition your contribution (only £25 annually) will help us maintain and develop our website for future users.
Who's new
- Jaffa_JIM_23
- Wrabstar
- GG
- KTMSCANIA22
- 280ge
Thank you to you both for your advice. I wonder if it may be the ABS as fixwin38 also sent me a message saying much the same thing as you, axel, regarding ABS. However Gsingh has mentioned some things to look at. I have to book it in for it's MOT and some work in the next month, so will print his suggestion off to get the garage to check what he has suggested. I have no idea about the brake fluid, but from what you and fixwin38 have said, it may well be the ABS.
As long as it stops when I want it to, that is the main thing.
But hey, aren't they good in the snow?!