TD4 Brakes Overheating

Erm, just a thought, but how good are your front wheel bearings? I had an old Fiat years ago which kept heating up on one wheel and it took me ages to figure out that it was a bit too much play in a wheel bearing that was causing the brakes to rub when cornering.

Clanforbes said:

Now that I think about it, I have seen these valves fitted on the rear axles of some cars and the linkages went from the axle mounted valve to the under bodywork or chassis of the car. I think in some cases, the valve only ever effects the rear brakes so the adjustment simply increases, or decreases, the flow of fluid to the rear brakes. Therefore, there could be only three pipes, the supply and one to each wheel.

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The freelander 1 has indendant rear suspension though.....

Clanforbes said:

Erm, just a thought, but how good are your front wheel bearings? I had an old Fiat years ago which kept heating up on one wheel and it took me ages to figure out that it was a bit too much play in a wheel bearing that was causing the brakes to rub when cornering.

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One wheel bearing makes a little bit of noise when turning to the left... Thats the passenger front i think... but both fronts heat up in equal ammounts so i doubt it...

bearmatthews said:

The freelander 1 has indendant rear suspension though.....

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If this is the case I wouldn't be surprised to either find two indepenant valves or just one linked to one side only, which would control both sides (they would probably assume the car would be sitting pretty level when loaded.)

As said above, I don't know if these are fitted to Freelanders, or even if they are used at all with ABS systems, but someone with more knowledge of your car will be able to tell you for sure.

Did you check the condition of the piston before you squeezed it back in with the G cramp ?
Even if the gaiter is perfect the piston could be dirty .Years ago I had to remove and clean crap and corrosion off a piston with a fine wire wool (can't remember what vehicle).
I learned here ,that you should open the bleed nipple before you press the piston back in.

Do the wheels spin reasonably freely when off the ground?
What happens if you apply the brakes when the front wheels are off the ground, do they bind a little?
Does the problem arise after a long drive or does it start straight away?

I know it sound daft, but try taking the car for a drive but drive very carefully using only the handbrake, then without you touching the footbrake, see if they still get hot.

Now we are into the realms of guesswork. Are the discs and pads the right ones for the car? Maybe the discs/pads are too thick and not allowing the brakes to back off completely after use. Although disc brakes in reality don't back off, they simple reduce the pressure but still make slight contact with the disc, so if there is even a slight resistance to the pedal pressure backing off properly the brakes will still be applied to some degree.

I have even heard of cases where the bore of the cylinder the piston runs in becoming slightly oval which was causing the piston to stick in the bore. Though my only experience of that was when I tried to squeeze the piston back into the bore, it would slide in a little uneven and jam like an askew drawer in a cabinet.

OldIrishWulf said:

Did you check the condition of the piston before you squeezed it back in with the G cramp ?
Even if the gaiter is perfect the piston could be dirty .Years ago I had to remove and clean crap and corrosion off a piston with a fine wire wool (can't remember what vehicle).
I learned here ,that you should open the bleed nipple before you press the piston back in.

Click to expand...

Hey Wulf thanks for your input
Yes i pulled back the gaiter(which is in good nick) and had a look, looked clean,dry and rust free, squirted a little wd40 in there and pushed it back in with a g-clamp.
However, I DID NOT open the bleed nipple.... I have never had to or done it before when pushing a piston back in... so why would i have to open the bleed nipple?

Clanforbes said:

Do the wheels spin reasonably freely when off the ground?
What happens if you apply the brakes when the front wheels are off the ground, do they bind a little?
Does the problem arise after a long drive or does it start straight away?

I know it sound daft, but try taking the car for a drive but drive very carefully using only the handbrake, then without you touching the footbrake, see if they still get hot.

Now we are into the realms of guesswork. Are the discs and pads the right ones for the car? Maybe the discs/pads are too thick and not allowing the brakes to back off completely after use. Although disc brakes in reality don't back off, they simple reduce the pressure but still make slight contact with the disc, so if there is even a slight resistance to the pedal pressure backing off properly the brakes will still be applied to some degree.

Click to expand...

• The wheels spin very freely, until the drivetrain stops it coz the other wheel is on the ground.
• I can apply the brakes, they stop the wheel spinning, and then i can release the brake and the wheel will spin freely again. All as it should.
• If i went out and did the handbrake test as u describe i would already know the outcome. The front wheels will be cold because they arent binding which i why you would do the test to see if the front wheels were binding or not.And the rears would have warmth coz they r doing the work...So theres no point me doing it...
• The discs and pads are the right ones for the car.
• The calipers 'back off'(release pressure) well enough to let the wheel spin freely immediately after releasing the brake pedal.

Clanforbes said:

I have even heard of cases where the bore of the cylinder the piston runs in becoming slightly oval which was causing the piston to stick in the bore. Though my only experience of that was when I tried to squeeze the piston back into the bore, it would slide in a little uneven and jam like an askew drawer in a cabinet.

Click to expand...

The piston and cylinder all seem fine and run in and out freely so im pretty sure the calliper arrangement is all ok....

In that case, I have run out of ideas. The handbrake test would help to eliminate bearings being the cause tho' I wouldn't really expect it to be them unless they were so bad the car was bandy legged!!!

Sorry couldn't help more. Driving style maybe? Are you heavy footed on the brakes to save on your clutch?

I will keep an eye on this thread to see what the problem was once you get it sorted, just out of curiosity now, so please do let us know.

Clanforbes said:

In that case, I have run out of ideas. The handbrake test would help to eliminate bearings being the cause tho' I wouldn't really expect it to be them unless they were so bad the car was bandy legged!!!

Sorry couldn't help more. Driving style maybe? Are you heavy footed on the brakes to save on your clutch?

I will keep an eye on this thread to see what the problem was once you get it sorted, just out of curiosity now, so please do let us know.

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The bearings aint that bad! lol i think i can rule them out tbh...
The breaks heat up over a very shory journey (10 miles it took them last time with some small downhill sections to get smoking hot!!!!)
Im not heavy footed on the breaks, and ive had a new clutch just after christmas as the dual mass fly wheel died in the snow and I though whilst I was in there I would do the clutch too, for all the work it takes to do it!!! My point being im not worrying about my clutch as it should outlive the car!! ahhaha
I will keep you posted on the outcome.
^^ Just coz ive said that doesnt mean im not open to any more help or suggestions from any other helpful and knowledgeable souls out there!!!!!!

its nothing to do with compensator valve and if pistons or slides are free ,and wheel brgs fine (symptom of poor wheel brgs is pulsing when pedal pressed) its normal for brakes to be hot after use front alot hotter than rear as they do 80%of work ,your forward motion is turned to heat as energy cant be lost just converted,if its only hot after braking an not during normal driving fit new discs ,pads

Compensator valve - thanks James, I was damned if I could remember what it was called.

Just to point out,
there is no compensator valve on the TD4 as all lines run to/from the ABS pump and contoller unit.

It may be that the rear brakes are not set correctly - the Automaitic adjusters are crap and belong in the 1960's

The front disc brake calipers also suffer from the pin/bolt sliders sticking

It is also possible to push crap back up the line when pushing the caliper pistons in - this will gt into the ABS valves on the pump.
This is why it is recommended to slacken the bleed nipples when retracting those caliper pistons.

jamesmartin said:

its nothing to do with compensator valve and if pistons or slides are free ,and wheel brgs fine (symptom of poor wheel brgs is pulsing when pedal pressed) its normal for brakes to be hot after use front alot hotter than rear as they do 80%of work ,your forward motion is turned to heat as energy cant be lost just converted,if its only hot after braking an not during normal driving fit new discs ,pads

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Indeed, the pistons and slides are freee. The wheel bearing are ok too. Yes i know front will be hoptter than the rears but not stinking and smoking after a 10 mile journey with a few small hills!
Brembo do brake disks and pads for the TD4... Should I?

Clanforbes said:

Compensator valve - thanks James, I was damned if I could remember what it was called.

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Yep, the the 'valve thingy' you were on about that the TD4 doesnt even have! lol

Mark2 said:

Just to point out,
there is no compensator valve on the TD4 as all lines run to/from the ABS pump and contoller unit.

It may be that the rear brakes are not set correctly - the Automaitic adjusters are crap and belong in the 1960's

The front disc brake calipers also suffer from the pin/bolt sliders sticking

It is also possible to push crap back up the line when pushing the caliper pistons in - this will gt into the ABS valves on the pump.
This is why it is recommended to slacken the bleed nipples when retracting those caliper pistons.

Click to expand...

Rear brakes not set correctly? Automatic Adjusters? The shoes are snug within the drum when i re-fit them.... Does this mean they are well adjusted?

Ok, thanks for explaining why i might want to open the bleed nipple but it seems too much hastle for the tiny chance there might be some 'crap' in the line

if everything mechanical is fine then can only be poor pads or discs,they can only overheat due to sticking on or rubbing due to worn brgs or calipers etc the rear nor working wouldnt have that much effect,i work on alot of lrs with very poor rears were disc is rusty thru lack of use but dont get your apparent problem ,brembo if you like but std would be fine ,i rather like ebc,compensator valves tend to be only used on vans etc with variable load driving modern cars compensate through master cylinder

bearmatthews said:

Hey Wulf thanks for your input
Yes i pulled back the gaiter(which is in good nick) and had a look, looked clean,dry and rust free, squirted a little wd40 in there and pushed it back in with a g-clamp.
However, I DID NOT open the bleed nipple.... I have never had to or done it before when pushing a piston back in... so why would i have to open the bleed nipple?

• The wheels spin very freely, until the drivetrain stops it coz the other wheel is on the ground.
• I can apply the brakes, they stop the wheel spinning, and then i can release the brake and the wheel will spin freely again. All as it should.
• If i went out and did the handbrake test as u describe i would already know the outcome. The front wheels will be cold because they arent binding which i why you would do the test to see if the front wheels were binding or not.And the rears would have warmth coz they r doing the work...So theres no point me doing it...
• The discs and pads are the right ones for the car.
• The calipers 'back off'(release pressure) well enough to let the wheel spin freely immediately after releasing the brake pedal.

The piston and cylinder all seem fine and run in and out freely so im pretty sure the calliper arrangement is all ok....

Click to expand...

Now I do lots of stuff with motorbikes and we don't use WD40 on the pistons because I believe that it can cause the piston seal to swell and so cause the brake to stay on! You should use red grease.

I am sure there will be other opinion on this but I think I would rebuilding the caliper- easyish job on a bike - cannot think it too difficult on a Freebie

Hello everyones!! Im rodrigo from Chile and i have the same problem, the brakes is overheating after 10 kms (front and rear specially left one), the hdc amber ligth is on when this happen. Do you solve this??? Thanks

Hi Bear,
To pick up on Wolfie and Marks point re. the ABS unit - this controls all of the brakes via the pump and valve assembly inside controlled by the ABS ECU.
IF you have pushed back the pistons without opening the bleed to vent the fluid you MAY have pushed crap back into the ABS unit. (assuming yours has ABS?)
This could cause your symtoms.
I recall a few posts on here where braking problems eventually got traced back to the ABS unit and either an expensive replacement or copious bleeding seemed to be a solution.
When working on the calipers it seems like a small chance of it actually happening but the threads on here seem to say otherwise - always best to open the bleeds when pushing the pistons in and then bleed well - just in case? (20/20 hindsight)
You did bleed the system after pushing the pistons in didn't you?

Another thought - some have posted faults with flexible brake caliper hoses that have separated internally and the inner section collapses to form a sort of valve and hold some fluid pressure onto the cliper and so hold the brakes slightly on?

You seem to have covered off most of the mechanical causes - only leaves you the fluid area to be keeping the brakes on?

Keep us posted.