Clunking noise when breaking

[AGM]

Hi all, back for some more advice please!

We're currently about to finish a 2000 mile round trip and have just noticed this morning a clunking noise every time we brake at low speed. Any ideas what it might be?

We have about another 150 miles to get home tomorrow so hoping nothing too serious!

Thanks in advance!

Alex

 

[clivehorridge]

I'm no expert at all, but:

(i) If it's the brakes and the noise is coming from the front and the brakes are working well, it could be the caliper mounting bolts coming loose. It's a bit of a drastic guess but I can't think of another cause, if it's the brakes.

(ii) Otherwise, it could be excess play in the pivot bearings (top & bottom "king-pin" bearings). If it is you may also feel some knocks on cornering or even in a straight line and may feel a bit of excess play in the steering.

(iii) a loose wheel?

If it's (i) or(iii) I suggest you have a look straight away, is the noise from the front and from one side only? (not much info to go on at this end);

If it's (ii) then it can wait till you get home, but have it checked out.

Best of luck...

 

[Pumpy]

caliper bolt loose/missing?
(only had it happen on a LR tho!)

Best finding which wheel it's coming from and have a look if you suspect it's from brakes really, suppose could be one of the bushes as the weight shifts or something else less important!

 

[StarCruiser]

Calliper bolt sprang to mind here. I've had one drop out before (my fault ) and the calliper eventually digs itself into the inside of the wheel with fairly obvious lurches when reversing (depending on the bolt that's dropped out). Easy enough to find by having a crawl under the truck and having a poke about. Also, note when the clunk occurs. Is it getting worse? Drive alongside a wall with the windows open and try and see where the sound comes from or have somebody walk alongside while you initiate it. That sort of thing.

 

[AGM]

Thanks! Missing calliper bolt it is.

Have tightened the one that's still there and are looking at a long, slow drive home tomorrow.

 

[StarCruiser]

Thanks! Missing calliper bolt it is.

Have tightened the one that's still there and are looking at a long, slow drive home tomorrow.

Available for a few pounds from your local Toyota dealer or Karl I guess. I've tightened mine with a torque wrench and so far so good. They do get a pretty good tightening.

Glad you found it. It may be a good idea to stop every so often and inspect/tighten on your way back just to be on the safe side.

 

[Julian T]

Thanks! Missing calliper bolt it is.

Have tightened the one that's still there and are looking at a long, slow drive home tomorrow.

Speed is not the issue, using the brakes is

 

[clivehorridge]

Good news you've found the problem.

It's a thought, but whichever one is missing, it would be safer for the missing bolt to be on the trailing side of the caliper, i.e. the one nearest the front of the truck.

That way the disc won't be trying to force the caliper away from the hub and towards the wheel rim where it will do damage.

 

[Dave2000]

If it is not too late? I read elsewhere you can use one of the hub bolts, apparently it is the same thread/pitch?

regards

Dave

 

[AGM]

Thanks all - and did get home safely... With minimal brakes and regular tightening!

 

[frank rabbets]

Those bolts weren't done up properly. People say bolts rattle undone etc etc. Well if that happened almost every man made machine on earth would break down.

I've never come across this. Glad it's sorted.

 

[clivehorridge]

Good to know you arrived safely.

Brush the threads up clean, a spot of grease, and torque them up properly. They won't come loose if torpedoed correctly.

Some folks torque bolts up with dirty threads and no grease, and half the torque resistance is consumed by the dirty threads, so they never get properly tight.

 

[flint]

As Clive said, just a little spot of grease or preferably copper anti seize. Most torque specs are for clean, dry bolts unless otherwise stated. If you grease them up too much, you’ll over tighten at the specified setting.

 

[Dave2000]

Funny this has been cited as a common problem on US models? I do them up tight to torque but use thread lock, the lube of the chemical allows the bolt to pull to torque properly and then sets hard, never lost one yet.

regards

Dave

 

[Pumpy]

I'd agree with Dave, threadloc rather than grease, LR caliper bolts come with threadloc already on them, I used copperslip on my LR calipers, torqued up propper, they still came out!

 

[clivehorridge]

Sorry if I've misled (in my ignorance) but the beauty of this forum is that folks suggesting the wrong thing (like me) promote the more informed to post a correction.

More power to the forum!

 

[Dave2000]

Sorry if I've misled (in my ignorance) but the beauty of this forum is that folks suggesting the wrong thing (like me) promote the more informed to post a correction.

More power to the forum!

Hmmm......an answer worthy of a politician Clive!

regards

Dave

 

[flint]

I’ve learnt something new too.

 

[clivehorridge]

Hmmm......an answer worthy of a politician Clive!

regards

Dave

Utopia I'm afraid Dave, they neve admit to being wrong!

 

[AGM]

Thanks again for the help - threadloc on order!

On another note, where do I go about finding all the various torque specs? Is there a library / document I can download from somewhere?

AGM