S Type DSC light

[catcargin]

Just thought i would share my experience concerning my rear brakes and DSC light on my 3 litre S Type.

My rear brakes became very noisy under hard braking and when checked at the garage the pads were worn right down and one caliper was sticking.

New pads were fitted and caliper unjammed.However the road test found another problem,the sticky caliper was still sticking a bit and because of the new pad thickness the the brake got very hot,the car vibrated at high speed,then the DSC light came on, and then other brake got vey hot.The DSC light would come on after about 2 miles or when the brakes got hot.The dilema then..were the hot brakes causing the DSC light to come on or was the DSC faulty and applying the brakes causing them to overheat?

I bit the bullet and had two new calipers fitted and road tested it for a while with DSC turned off,Brakes stayed normal temp even after hard use.Then turned DSC back on and bingo, no light comes on,no overheat and no vibration.

So yes a caliper was sticking causing the brake to overheat but also because of that the DSC system was trying to compensate for the unstability on the overheating side by applying the brake on the other side.!!!hence the DSC light and hot brakes.

So problem solved and no fault with the DSC system after all, indeed quite the contrary.So dont automtically assume DSC fault if light comes on its worth checking the brakes first.

[catcargin]

Not quite the end of this story !

I found later the rear offside brake was still getting hot(ish) though not as bad, and had twice the amount of brake dust as the near side,not good.

To be on the safe side i carried out the Electric Parking Brake re-set procedure in accordance with the Jaguar Technical Bulletin,as according to Jaguar this has to be done every time rear brake pads/calipers/discs are replaced or worked on.This has improved things but i have booked it into the garage so they can check if the EPB cable/Lever is fully releasing which i reckon its not.

Will let you know!

[catcargin]

Still not quite the end !!!

Rear offside brake caliper must still be binding a little as that wheel has loads of black brake dust whereas the other three wheels have little or none.

Have located a one man band Jaguar specialist with 50 years experience of working on Jaguars,have booked it in with him on Monday and he has agreed to look at the rogue caliper ,he reckons he knows what the problem is...we will see.

Will report back asp.

[catcargin]

Well the Guru with 50 years experience of Jags has cracked it.

He road tested the s type and put it straight up on the ramp wheels free.The rear offside wheel was very hard to turn,which meant that when the calipers overheated in the past due to incorrectly fitted pads the heat dried out the grease in the wheel bearing so it was basically siezing up, and overheating more,and so although i thought it was still the caliper it now wasn't.

The excessive brake dust was being caused by the worn discs wearing away the pads at the outer edge where the disc had more metal left than the worn section.

So, two new rear discs,new wheel bearing,re-set handbrake and hey presto a good braking non overheating calipers without excessive brake dust....simple! :D .The guy is a craftsman so if you have a Jag problem and you live in Dorset let me know and i will give you his number.I haven't posted it here as i didn't clear it with him to do so.

[catcargin]

An extra tip he pointed out.

The brake pads have a raised metal 'nodule' on the back which must fit into one of the grooves on the front of the caliper piston,if it doesn't the pads will bind/jam overheat leading to exactly my problems.

[Wealy]

What is the handbrake re-set procedure that you talk about in the first post?

[catcargin]

Hi Mark

this is for S type EPB from Jaguar technical bulletin JTB00084

Turn ignition off

Remove EPB fuse F35 ( for S type ) for 30 seconds

After 30 seconds replace fuse and start engine

Message 'not calibtated' or 'apply foot/parking brake' will display

Press brake pedal firmly 5 times

Then lightly hold foot on foot brake

Apply EPB using switch ( it will re-set )

Release EPB using switch

Then release foot brake

Confirm warning messages no longer displayed

Apply and release EPB 5 times to ensure correct operation

Worked for me.Would always advise checking technical bulletin for your model/year

[taxijag]

Hi Peter, could you pass on the details of this Jag guru as i'm also in deepest Dorset. Thanks Eddie.

[catcargin]

Hi Eddie,

I'm sure he wont mind me posting this.

The chaps name is Don Hansford , contact number 01202 691706 , garage premises in the lane opposite the Holme Bush pub on the Wareham to Corfe Mullen road.

Can be tricky to pin down as he is on his own, keep trying !

Decades of experience, 30 years his own business, knows Jags inside out.

Cheers.

Pete.