Disks?

[ozzy666]

lo all its me again the dude who dunt no owt bout cars and is always having a problem with something

i've had a boot rattle and and thinking it may be the anti-roll bar bushes or rubbers. i'm getting it checked monday,i've also noticed that my brakes sound like they are grinding abit so i went to have a gander at them and noticed both the front brake discs were red hot [too hot to touch] the back ones were stone cold,normal??? or something wrong???

thanks rob

[sotal]

Depends how you have been driving.

Driving to work mine are hot at the front and just very slightly warm at the back.

If I drive a little more enthusiastically then my skin fizzes and goes hard when I touch the front ones (and I learn not to do it again) and the back ones are warm to hot.

[chris202]

lo all its me again the dude who dunt no owt bout cars and is always having a problem with something

i've had a boot rattle and and thinking it may be the anti-roll bar bushes or rubbers. i'm getting it checked monday,i've also noticed that my brakes sound like they are grinding abit so i went to have a gander at them and noticed both the front brake discs were red hot [too hot to touch] the back ones were stone cold,normal??? or something wrong???

thanks rob

I think the brake problem is ok , maybe check your fluid ? am sure the front brakes take more of a hammering than the rears - so after a bout of "rallying" the fronts will be a lot warmer than the rears .

I've a boot rattle too but its just the rear parcel shelf and its poor mounting system , i think i'll have a look at diy fixing it when the weather improves a bit .

Am sure a local celi-genius (gt4 , daktari etc etc ) will be along soon to give some proper help

[ozzy666]

i had brake fluid changed as soon as i bought

[martin_longbow]

Yep heavy use will make them V warm. To make sure they are not sticking on do two things

Try this, from cold can you roll the car (ie push it easily) on flat ground with the handbrake off and the car in neutral. It should not take much force to push the car simply push the main front post with the door open and it should move

after a normal drive perform the same test, if the car is not willing to move as easily then you brakes are likely to be sticking on. They may simply need a service. If your car wont move then they are defo sticking on.

This is not a technical test but is a simple check to see if you need to get some further investigation performed.

[daktari]

Rob. The brakes are biassed towards the front. The rears just help balance the car up a bit. So your fronts are going to be considerably warmer than the rears. Having said that, the rears should at least be warm.

Are the rear discs shiny? It would be worth whipping the wheels off and having a closer look.

Have a good look at all four discs and pads, Don`t be takin chances where brakes are concerned.

If it sounds like the fronts are grinding it could be time to replace the discs as well as the pads.

[mikeb]

The rattle is likely to be an anti roll bar bush.

The rear brakes do very, very little work. Most of the weight is at the front to start with, also the brakes are heavily biased towards the fronts. Just try and lock a rear wheel - it'll never happen on an even surface. It is normal for the fronts to be hot (too hot to touch) and the rears cold, if your brakes are sticking then they would be very hot, you would likely smell it.

[ozzy666]

thanks for the reply lads daktari ,the rear discs are not as shiny as the front they are abit rusty and were'nt even warm they were cold.i do sometimes smell something but it aint a strong smell the only time i smelt something strong was wen i thrashed it in first then parked up in work car park [had **** on] that will prob be some other problem i'll have later in the year i will try pushing car on flat road

[daktari]

thanks for the reply lads daktari ,the rear discs are not as shiny as the front they are abit rusty and were'nt even warm they were cold.i do sometimes smell something but it aint a strong smell the only time i smelt something strong was wen i thrashed it in first then parked up in work car park [had **** on] that will prob be some other problem i'll have later in the year i will try pushing car on flat road

Basically the optimum balance (brake bias) is obtained when a vehicle's front-to-rear bias exactly matches the same vehicle's dynamic front-to-rear weight distribution (or weight bias) under a given loading and deceleration condition.

Under braking the cars weight is transfered to the front. This means that the front brakes should be increasing effort and the rears lessening. But still performing so as to maintain a balance. The harder you brake more effort is needed at the front. This is achieved through the use of a load compensating valve. Which effectively reduces the pressure going to the rear brakes which in turn diverts that pressure to the front brakes. However not all the cars weight is transferred to the front so some braking force must remain at the rears to maintain balance.

The condition of Ozzys rear discs suggests to me that the rears aren`t even doing the minimal work that they should be.the rears may not get that warm. But they shouldn`t be cold. And i would expect the rears to be doing something other than going rusty.

I`m thinking because of the additional rear weight carried by the 4WD vehicle the rear brakes should be working harder than on a FWD vehicle which has more weight bias towards the front. This is why i stated that the rears on ozzy`s 185 should at least be warm. They are on mine (And shiny) when i`ve driven any distance where an amount of braking is called for. I wouldn`t mind betting that the LCV is different for a 182 and 185.

[ozzy666]

you the man!! i will have me garage look into this on monday wen i hopefully found out wat that rattling is.thanks alot dude.HOPE I ANT BOUGHT A LEMON!! its in too gooda condition to get rid even if i have

[sotal]

thanks for the reply lads daktari ,the rear discs are not as shiny as the front they are abit rusty and were'nt even warm they were cold.i do sometimes smell something but it aint a strong smell the only time i smelt something strong was wen i thrashed it in first then parked up in work car park [had **** on] that will prob be some other problem i'll have later in the year i will try pushing car on flat road

You shouldn't have rust on them after a run, and they definatley shouldn't be cold. Go take it for a good ride and test the brakes a bit then feel them when you get back - if they're still cold get them looked at

[mikeb]

This is why i stated that the rears on ozzy`s 185 should at least be warm. They are on mine (And shiny) when i`ve driven any distance where an amount of braking is called for. I wouldn`t mind betting that the LCV is different for a 182 and 185.

Does ozzy have a 182 or a 185 though? His profile says '91 celica GT'? I agree that the rears on a GT4 will be a bit more active. I had to replace the rear discs and pads on my gt because they see so little use that the discs corroded terribly - under normal use they weren't even seeing enough force to keep them clean.

I suspect that the biasing and adjuster are very conservative with how much braking force they let the rears have - the last thing any manufacturer wants is a car that locks the rear brakes before the fronts.

[daktari]

you the man!! i will have me garage look into this on monday wen i hopefully found out wat that rattling is.thanks alot dude.HOPE I ANT BOUGHT A LEMON!! its in too gooda condition to get rid even if i have

Just get em to put it on the old brake tester that should show any problem up. Not too sure what the load valve is like on celicas. Strangely enough i`ve never bothered to look at mine. But i suspect if there is a problem it`ll be with that. Internal corrosion possibly.

[ozzy666]

i have the 182 [internal corrosion,don't like that word m8]

[daktari]

i have the 182 [internal corrosion,don't like that word m8]

It`s quite a common thing on most cars. People neglect to change the fluid regularly and water does the rest. Same goes for the ABS pump..... And THAT is expensive. Sorry i thought you had the 185.... Appologies mike.

[martin_longbow]

Wow there a lot of techie stuff flying around here that is all very correct but as previous I suggest the simple test to see if they are sticking, ie push on flat ground when cold, go for a run ensure you use the brakes and then push on flat ground after run.

Another way is simply to see if the car is rolling down a slight graidient after the car has been a run. If brakes are sticky the car will be slower to free wheel or indeed may not actually free wheel.

Best bet would be to get them serviced ensuring the back brakes are stirpped cleand and pistons worked in and out. If the disks do not clean up (remove all the rust from the face of the disk) after that you have to look at new disks and or maybey calipers stripped and cleaned.

New disks = Brakes International. Super to deal with, and I just did a trawl of suppliers in December. Went with drilled and groved all round. I had a sticky calliper on the front and two no workey callipers on the rear.