Wheel wobble

[toyota]

Hi Guys

Once again i need some advice. When traveling down hill " like the Kei cuttings"
at about 80 kph and i apply brakes the front wheels go into a wobble, when this happens i have to slow down quickly or it gets worse. My question is why does it only happen on a down hill and what is the cause. It does not do it on level roads or uphills.

Thanx in anticipation
John

[Toybox]

Does it only happen when you apply brakes? If so it sounds like your brake disks are warped. have them skimmed or replaced and the problem should go away.

[toyota]

Yes it does only happen when i apply brakes and only when going down hill.

[Hoppy]

Skim the front discs,
check for play on steering joints,
check steering shock,
check shackle bushes & U bolts.

[toyota]

Thanx will do as soon as the alternator has been put back into the vehicle

[Mud Dog]

Hi John, did you get Norman to sort out your ally problem?

[CasKru]

Also while you are at it, check the torque rod rubbers and mounting points.

PS: don't forget to check the engine oil level as well

[Hi-Hilux]

And the window washer bottle's level lol lol.

Die discs is ge worp, my ifs het dit ook gehad.

[Gunta]

maybe your wheel nuts are loose.

[Mud Dog]

Guys, John is no youngster, but also no fool ... he runs an engineering shop. I think he's just a little rusty from too much admin and wondering why it occurs only when applying brakes on a downhill. This implies something besides or on top of warped discs. Hoppy's suggestion of checking steering links etc besides disc seems to be more on the money.
BTW, John's vehicle is an SFA, so there's not a lot that could be wrong.

[Gunta]

Hey was only kidding Is there shudder as well when you brake or only wooble. If the disc's were warped you would get a shudder and also a feeling of grab, letgo, grab. A wobble seems to me like something on the steering or the steering shock. What can also do it is if you have larger tyres and they track on uneven surfaces.

[Mr_B]

It may well be time to sell the vehicle... this issue is not easily resolved!

Time for an upgrade

By the way... John... how much u want for her... :shifty:

Mr B

[Gunta]

Bretton are you looking for another one?

[toyota]

Thanx guys i will check all the suggestions and advice you have given, all help is appreciated. Andy yes he has the alternator and is going to overall it for me. Sorry Bretton you wouldn`t get me to get rid of it for all the money in the world but maybe for a double cab Cruiser.

[JBurger]

I had a similar problem for quite a while. I could not understand why it only occurred on a down hill. The Toyota tech told me it is because the vehicle is leaning on the front suspension and the rear is unloaded. This changes the brake force distribution – more braking in the front. With the front discs wearing unevenly, the wobble is noticeable on a downhill but not so much on level surface or on an upslope. (and during high speed, hard application..) They skimmed the front discs and problem solved.

[Mud Dog]

I believe that any front wheel wobble which occurs under braking is precipitated by warped discs, however slight. What I'm trying to say is, yes, have the discs skimmed if they still have enough meat, otherwise replace, but if the discs are only ever so slightly warped and the steering linkages and damper are all in good order, you might not even notice the shudder. If on the other hand with worn linkages, any slight disc warp will cause a shudder that is pronounced. So, yes, see to the discs, but do not neglect to check for play on the ball joints of the tie rod, drag link as well as in the steering box itself. Wheel bearings that have play will also have an effect and should also be checked .... remember that wheel bearings are not always noisy if there is play ... usually only when they are pitted or damaged.

[merwn]

Hi

Wil ook iets vra oor die brieke.Ek het nou die dag in die dorp gery so 80Km/h
toe draai 'n kar voor my in het die briek getrap harder as normaal getrap maar nie so hard dat die wiele lock nie toe ry ek amper die barrier in die middel man weg toe ruk die bakkie kwaai na regs, kan, iemand vir my se wat dit kan wees

[Mud Dog]

The one side is obviously braking better than the other. There could be a few reasons for that. Firstly check that the pads are not excessively worn down and need replacement, but more importantly IRO your problem look to see that there is no oil or brake fluid contamination on the pads due to possible leaks. If there is contamination, you have to replace the pads after repairing the source of the leak. It could also be that one calliper is not operating properly. Each front calliper has 4 pistons, two on each side. It can happen that one or more pistons become jammed as a result of debris build up. With the wheels off and on stands you can check each side by prying the pads away from the disc carefully so as not to damage the linings, and then getting someone to tramp brakes from inside while you watch that all pistons are pushing on the pads. (When you pry them back be carefull not to pry back so far that you have a reservoir overflow under the hood.) If there is a problem, it's best to strip both calipers and replace all the seals together after cleaning out and honing the cylinders if necessary. A remote possibility is that one set of pads has become 'glazed' and are not binding as they should .... this is not a problem that I have often heard of happening, but it is possible, especially if some backyard mechanic has used two different brands of pads on each side. The last alternative cause of your problem that I can think of is a brake line blockage or even air in the line on one side. The line would need to be irrigated (if blocked to clear the blockage) and bled.
Your problem is definitely brake related and that is where you have to look for the cause.

[merwn]

Die calliper het ek nuut oor gedoen ,en die pads lyk reg en daar is geen lek op die callipers nie en alles is vas geen speling op die bearings nie het ook agter gekom dat as ek normaal briek dan is dit asop die voertuig "weave"op die pad

[Mud Dog]

If it's weaving, then it's more likely to be one of the problems mentioned above with linkages.

[Mr_B]

It's also possible that the swivel bearings in the hubs are stoofed, not likely but still possible... only problem is that checking them involves stripping the hubs... not a nice job!

[Hoppy]

Haal jou voorste "calipers" af en kyk of al vier pistons in elkeen vrylik in en uit beweeg.
Die kits vir voor is omtrent R70.00 per kant en dis beter om hulle in elk geval te doen om roes te voorkom.
Trek die handrem stadig op en voel of jy daai "weaving" kry en of hy onegalig stop, dit kan maklik van agter af ook kom.

[Gunta]

Another thing to check is the rear brake shoes. You might have one wheel binding more than the other and that will definitely cause the bakkie to pull to one side under hard braking.

[merwn]

Dankie vir al die hulp,het so 3 maande terug die calipers ge-overhaul,
Het die naweek voor nuwe briek blokke ingesit en gaan more die agterste skoene doen sal laat weet hoe dit gaan

Dankie
Nick