4.2 Rear Discs - One Hotter Than Other...?

[tash2007]

Hi again

got the rear springs changed and within a week or two I happened to notice that one rear disc is runnning a lot hotter than the other...? what are the poss. diagnoses here and how to test for them?

New rear discs and "handbrake kit" 15 months ago (not by me).

I came up with:-

Handbrake sticking?

Caliper sticking?

Car seems to roll back and forth freely without any "sticky bits", handbrake is adjusted up to 3 clicks and works OK and appears to release OK on both wheels.

Looked at calipers on both rears and apart from pins being a bit stuck in calipers (easily freed off) all seems OK - calipers can be made to "operate" by hand -although the movement is small and both rears pads don't fully clear the discs -but that seems normal is it?

So why is one disc getting a lot hotter than the other?

Any assistance pointers gratefully received

Cheers

Jim

[firemac]

Hi again

got the rear springs changed and within a week or two I happened to notice that one rear disc is runnning a lot hotter than the other...? what are the poss. diagnoses here and how to test for them?

New rear discs and "handbrake kit" 15 months ago (not by me).

I came up with:-

Handbrake sticking?

Caliper sticking?

Car seems to roll back and forth freely without any "sticky bits", handbrake is adjusted up to 3 clicks and works OK and appears to release OK on both wheels.

Looked at calipers on both rears and apart from pins being a bit stuck in calipers (easily freed off) all seems OK - calipers can be made to "operate" by hand -although the movement is small and both rears pads don't fully clear the discs -but that seems normal is it?

So why is one disc getting a lot hotter than the other?

Any assistance pointers gratefully received

Cheers

Jim

Over-torqued wheel nut causing bearing to run hot? Insufficient bearing grease on hot side?

[tash2007]

Hi again

got the rear springs changed and within a week or two I happened to notice that one rear disc is runnning a lot hotter than the other...? what are the poss. diagnoses here and how to test for them?

New rear discs and "handbrake kit" 15 months ago (not by me).

I came up with:-

Handbrake sticking?

Caliper sticking?

Car seems to roll back and forth freely without any "sticky bits", handbrake is adjusted up to 3 clicks and works OK and appears to release OK on both wheels.

Looked at calipers on both rears and apart from pins being a bit stuck in calipers (easily freed off) all seems OK - calipers can be made to "operate" by hand -although the movement is small and both rears pads don't fully clear the discs -but that seems normal is it?

So why is one disc getting a lot hotter than the other?

Any assistance pointers gratefully received

Cheers

Jim

Over-torqued wheel nut causing bearing to run hot? Insufficient bearing grease on hot side?

intriguing... what other symptoms could one expect (currently or coming next)??

cheers

Jim

[Jamesbelfast]

If a wheel bearing has been overtightened or has lost lubrication sooner or later it will fail usually beginning with a humming sound. It's rare for a wheel bearing to overheat unless it just about to seize.

One of the golden rules of engineering when sopmething goes awry is to doubl;e check the last maintenance. And as new springs were fitted recently which involved lowering the rear axle I suggest the handbrake cables and their adjustment be checked out.

Releasing the handbrake adjustment off a little and then a test drive would eliminate that as a possibility.

[bothwell_buyer]

A quick check on the torque of the rear nut.

Calipers - Toyota are not my favourites as I've had a lot of trouble with them... so worth checking that they are retracting

And as above, maybe the handbrake cables are over-tight??

The 2 latter points would normally get thrown up on an MOT I think.

[tash2007]

If a wheel bearing has been overtightened or has lost lubrication sooner or later it will fail usually beginning with a humming sound. It's rare for a wheel bearing to overheat unless it just about to seize.

One of the golden rules of engineering when sopmething goes awry is to doubl;e check the last maintenance. And as new springs were fitted recently which involved lowering the rear axle I suggest the handbrake cables and their adjustment be checked out.

Releasing the handbrake adjustment off a little and then a test drive would eliminate that as a possibility.

OK sounds worth a try I'll back them off to 5 or 6 clicks and report back on results - cheers

Jim

[tash2007]

If a wheel bearing has been overtightened or has lost lubrication sooner or later it will fail usually beginning with a humming sound. It's rare for a wheel bearing to overheat unless it just about to seize.

One of the golden rules of engineering when sopmething goes awry is to doubl;e check the last maintenance. And as new springs were fitted recently which involved lowering the rear axle I suggest the handbrake cables and their adjustment be checked out.

Releasing the handbrake adjustment off a little and then a test drive would eliminate that as a possibility.

OK sounds worth a try I'll back them off to 5 or 6 clicks and report back on results - cheers

Jim

Busy on errands today so no progress on the handbrake slacken off n test BUT whilst out and about

1) every time I stopped I felt the temp of the rear discs and "the one" is sometimes warmer than the other but not as hot as it has been (yet)

2) last lap of the errands I heard at slow speed with windows down some telltale "pad-on-disc" squeal (is that the right word?) seemed to be once per wheel revolution - applying the handbrake gently did not make it worse or make it go away...

3) also from my quick "wheels off and look/feel about" inspection yesterday and having looked at a few other links and PDFs on parts and diagrams since, what do folks think about these discoveries:-

i) no park brake adjusting hole plugs in disc hubs

ii) pad pins held in with split pins not the usual spring clip,

iii) no anti rattle spring (on either rear wheel) though :unsure: as although they are in the parts diag in Anchormans excellent tech tip (4.2 Renew REAR brake pads)they aren't shown in the photos or reassembly instructions so are they "needed"?

In general do the above add any more in the way of clues to what's going on/likely culprit?

Again - thanks in advance

Jim

[Jamesbelfast]

Sounds like someone has done a butchers job - time to get the job done correctly me thinks.

[Big Kev]

Sounds like someone has done a butchers job - time to get the job done correctly me thinks.

Spot on from James....get a full new set of bits from that guy in Fred Flintshire, Kingo, and renew the lot, including high melty point grease (which I always forget.....)

Big Kev

Just a wee thought too, Tash....make sure all the wee sets of top / bottom stainless steel guides are present too.....could jam if they are missing....?

[tash2007]

Sounds like someone has done a butchers job - time to get the job done correctly me thinks.

Spot on from James....get a full new set of bits from that guy in Fred Flintshire, Kingo, and renew the lot, including high melty point grease (which I always forget.....)

Yeah i'm thinking I've been had

Anyone got a pointer to a parts diagram (with numbers ideally) to see what I need?

and how come the anti-rattle spring things aren't on Anchorman's write up on rear pads etc?

Just a wee thought too, Tash....make sure all the wee sets of top / bottom stainless steel guides are present too.....could jam if they are missing....?

mmm I've had yet another study of Anchormans' pad change writeup ....where are these exactly? caliper or pads or somewhere else?

thanks guys

Jim

[Big Kev]

Sounds like someone has done a butchers job - time to get the job done correctly me thinks.

Spot on from James....get a full new set of bits from that guy in Fred Flintshire, Kingo, and renew the lot, including high melty point grease (which I always forget.....)

Yeah i'm thinking I've been had

Anyone got a pointer to a parts diagram (with numbers ideally) to see what I need?

and how come the anti-rattle spring things aren't on Anchorman's write up on rear pads etc?

Just a wee thought too, Tash....make sure all the wee sets of top / bottom stainless steel guides are present too.....could jam if they are missing....?

mmm I've had yet another study of Anchormans' pad change writeup ....where are these exactly? caliper or pads or somewhere else?

thanks guys

Jim

The wee lugs of each pad slide aboot on these, Tash, as opposed to on cast iron bit...they are bright stainless, even when dirty, but Anchorman advised I should clean them anyway. Are the dwgs not in pinned section....?

[IanXT4]

On a 2004 the rears look like this, however my anti rattle spring is in two bits rather than the one shown

Components.pdf

[tash2007]

On a 2004 the rears look like this, however my anti rattle spring is in two bits rather than the one shown

thanks for that IanXT4, Kingo has confirmed to me that mine doesn't have anti rattle springs - so one less thing needed - thanks Kingo

So what's the deal with "pad shims"? do they just get reused when pads are changed? how do you assess whether they need renewing?

is there some element of measurement and choice of shim thickness? or is it a "one size shim fits all" job?

(Just trying to make sure I've got the bits I need before getting it all in bits )

Thanks again guys

Jim

[Joylove]

Anyone got a pointer to a parts diagram (with numbers ideally) to see what I need?

Parts diagrams are here.

http://www.toyodiy.com/parts/

[tash2007]

Anyone got a pointer to a parts diagram (with numbers ideally) to see what I need?

Parts diagrams are here.

http://www.toyodiy.com/parts/

thanks Joylove, I've been using that site for part numbers but where are the diagrams?

(Thought maybe my flaky browser (K-Meleon)isn't showing them but I checked in IE and still couldn't see any actual diagrams... I'd be V grateful if someone could show me where they are )

Cheers

Jim

[Parts-King]

Toyodiy does not have diagrams, if you want a diagram of your specific brake setup, PM me your email address

Kingo

[tash2007]

On a 2004 the rears look like this, however my anti rattle spring is in two bits rather than the one shown

thanks for that IanXT4, Kingo has confirmed to me that mine doesn't have anti rattle springs - so one less thing needed - thanks Kingo

transpires after all that mine DOES/SHOULD have anti-rattle pad springs in two parts as per IanXT4's pic - kit of 4 part ref 04948 £10odd +VAT apparently. :rolleyes:

Jim

[IanXT4]

I found a better TSB document that shows the separate anti rattle pins and explains how to assemble them on the calliper.

RAV rear brake assembly instruction.pdf

[tash2007]

I found a better TSB document that shows the separate anti rattle pins and explains how to assemble them on the calliper.

RAV rear brake assembly instruction.pdf

Superb thanks very much for that

Cheers

Jim

[Big Kev]

I found a better TSB document that shows the separate anti rattle pins and explains how to assemble them on the calliper.

RAV rear brake assembly instruction.pdf

Me too, Ian....wee mate has his to do soon, so have added this to file on my 'puter...."Anchorbrakes..."

Big Kev

[Parts-King]

so have added this to file on my 'puter...."Anchorbrakes..."

You can add files to a puter? wonders never cease :D: :D: :D:

[tash2007]

Hi

just an update and possibly more clues- been a few days and a few miles since this came to light and I've been checkig disc temps every time I park up - and everything seems back to normal temperature wise..

..although - for the past few days I decided not to use the handbrake unless absolutely necessary, parking up in gear and only really using it briefly for "hill starts"

- when I parked up once yesterday I applied the handbrake and then "allowed" the car to start rolling backwards as i let the handbrake off again - there was a "scrape and squeak" from the troublesome side rear as the brake "let go" does that mean anything to anyone?

(I have still to loosen the handbrake off a bit and tidy up the pads in the calipers with the correct springs /clips etc, hopefully I'll get time (and weather) this weekend....

Now where do I start on the next niggly thing in that corner - jiggly squeaky creaky noise over bumps, road imperfections, getting really tiresome also got a lot worse after same "monkey" put new rear springs on :censor: :censor: ....

Is that best on a new thread job or ??

Cheers

Jim

[Parts-King]

Jim, something is sticking, you need to get into the handbrake mechanism and start to look at what is not releasing, it might not be anything to do with the pads but the handbrake itself, there are brake shoes (not pads) on the inside of the discs that might need something freeing off

The squeaks etc might be that one of the new springs is not seated properly

Kingo

[IanXT4]

Sounds like you need to give everything a very good look over.

After I have removed the rear pads I usually find that the rear calliper has "lightly stuck" on its sliding pins (mine are well lubricated), it may need a gentle thump with the palm of your hand to free up.

If you have not done so I would recommend removing the two bolts holding the calliper and lubricate the internal sliding parts. I seem to remember that access is limited to these bolts, so a socket will not fit but a long (14mm ?) ring spanner will do the job.

With the calliper off it should also be easy to remove the disk and check the hand brake.

Brake calliper and parking brake diagrams attached.

Components.pdf

Parking brake components.pdf

[tash2007]

Jim, something is sticking, you need to get into the handbrake mechanism and start to look at what is not releasing, it might not be anything to do with the pads but the handbrake itself, there are brake shoes (not pads) on the inside of the discs that might need something freeing off

The squeaks etc might be that one of the new springs is not seated properly

Kingo

thanks Kingo, what should i be looking for/checking regarding seating of the spring?

I see there's a rubber? top "insulator cushion thing" at the top of the spring - is there a right/wrong way of fitting this? or, how to tell if it's sh@gd?

cheers once again

Jim