Thumping noise when braking - 2001 Sienna

I had the same thing happen on our 99 Sienna.
I makes a bump, bump, bump sound when you slow to stop.
After much trial and error and checking several things, I finally fixed the problem myself.
The cause of this is dust from wear of the rear brake shoes. It builds up and gets under the front of the shoes.
When it starts this, just pull off the wheel and rear drum. Take a leaf blower and blow all the dust from the brake shoe assembly. Do this outside and don,t breathe the dust. Best to wear a dust mask.
After a couple of times over several months, this will stop doing this.

had the same problem with the thump noise, this is due to the rear drum breaks not fully engaging (just part of the pad is catching in the drum), need to adjust the drum pads.

It may be something to do with new brake shoes 'seating' or wearing in.There are recommended procedures which can be read on the packaging of the relevant parts.Also it can be useful to drive in reverse and then brake,at various (safe) speeds,a few times,preferrably without stopping.For the first 200 k's try not to use brakes too harshly.(slow down smoothly)
And yes,once seated,any unusual noise when braking,would be miraculously absent.Now where can i see a diagramatic for my 1987 landcruiser hj75"troopy"rear drum brakes.The adjustment cog accessed from rear of drum (thru slot behind rubber seal at top) is not turning and think theres a latch which is like a rachet lock preventing me from loosening pads.Pads must be backed off so that i can remove the drum(already hammered etc,etc.)to check/replace pads and slave cylinders.Have no repair manual.Thanks if you can assist.jhon

But of course, it's a Toyota, so it never 'breaks.' (sic)

jak
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Tire sludge maybe?

I have no serious answer, but I just couldn't resist... :)

Ron

Hello,

I hate to ask, but are your lug-nuts in the rear properly tightened?

Best regards,

RG

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My Sienna has never done that.

Doc wrote,

After going through a number of disasters with a Ford 95 Windstar, we
purchased a 2001 Sienna, fully decked out. It has been a great van/car
- except for one problem. Whenever we slow down and stop, you can hear a
"thump-thump-thump" sound from (I believe)the rear of the car. I thought
the spare tire might be loose, but that checked out, and I couldn't
figure this out. It's VERY noticable. My local Toyota service guy told
my wife that this was "normal" for this car, annoying but normal. She
doesn't remember what he told her caused it.
Before I go down and talk to the service manager, I'd like to be armed
with any knowledge some of the folks her can provide. Surely this isn't
"normal"? They looked at the rotors and said they were fine, and there
is no symptom other than the sound. What could this be?
Thanks,
Doc


Doc,

I've driven many many customer's Seinnas and not heard this
thump-thump-thump on coming to a stop or immediately after stopping.
The 4wd suvs commonly make such sounds due to driveling windup in the
various U-joints, but not FWD vehicles like the Sienna.

Unless I'm severely misunderstanding your description of the sound, I
don't think it's "normal". Of course, without hearing it myself I can't
give you a clue as to what it might be, but if it seems to correspond
with the rotational speed of the wheels (slowing down as the wheels slow
down) the rear brakes/drums would be one of the first things I'd check.
If not related to wheel speed there must be something other than the
spare loose back there, maybe start out by removing any loose
paraphrenalia that may have accumulated in the rear of the interior
including stuff under seats or in storage compartments.

It's an unfortunate fact that not all Dealership service departments are
created equal when it comes to tracking down funny noises.

There are at least 5 other Toyota dealers within 30 miles of our store,
and we've had pretty good luck fixing funny noises that they've either
ignored or given up on.

Don't hesitate to try other dealers and even call the Customer Service
number in your owner's guide. We have had customers who were referred
to us by the Customer Service line after another local dealer was
unsuccesful in resolving a problem.

Good Luck and do keep us informed.

"Dammit Jim! I'm an Automotive Service
Technician, not a mechanic!!"

But Capt'n, the ethylene glycol solution is almost exhausted! The
combustion pods 'r' abou' t' explode, an' ah d' na how much longer ah
can hold 'er!

Steve S.

I had the same problem. Took to the dealer then found the defected rear drum ( oval shape ). Replaced rear drum, solved problem.

You have rotors in the rear? not drums? It sounds to me like they are warped. The Siennas with rear drum brakes have a big problem with wheel cylinders leaking, and the shoes getting saturated. Also the drums make noise and there is updated drums in a service bulletin, Ive heard them make all kinds of weird noises. Its not normal and it can be fixed.

Hello,

Our Sienna does not make ANY noises when breaking.

Best regards,

RG
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"Doc" wrote we slow down and stop, you can hear

Hey Doc, I predict that the answers you get from this group "There is no
problem, and if there is it is obviously due to owner neglect".

I had the exact problem with my 2k Sienna. Sounded just like a rear brake
shoe dragging. It only happened intermittently and at low speed braking.
First they replaced the rear cylinders, then they turned the rear drums,
then they said they couldn't recreate the problem. Finally it just quit
happening.

Charlie Parker

Now, now, he didn't say he wasn't changing his oil as required:-)

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Curtis Newton

<<remove .no-spam to reply http://surf.to/cnewton
ICQ: 4899169

Get on the phone and call all the dealers in your area. Try to call during a
slack period of the day. You can take your car to any dealer to get warranty
service.

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