Kuga Brakes Issue

[prepman]

Help!
Having a spot of bother with the Kuga brakes ....again. Had issues with brakes rubbing in past and replaced rear calipers which fixed issue Dec 2021. Prior to this the ABS module packed in and was repaired by a very reputable firm.
Now I've got rubbing brakes again..... I ran car then used temp gun to measure disc temps.
Front OS and rear NS were high ~170C.
As this is diagonally across and not on one axle is it likely to be an ABS issue?
Aren't they paired like this?
No fault lights. Will run diagnostics tomorrow, but very limited with the little unit I have.

 

[Guineafowl]

I’ve had mysterious rubbing calipers before - turned out to be the flexi hoses collapsing inside and acting as a one-way valve. Check for residual pressure by cracking the bleed nipple.

Diagonally opposed problem does suggest ABS unit, though. Is your brake fluid nice and clean? Moisture will cause corrosion.

 

[The_Yellow_Ardvark]

Can you run a test on the Master cy;inder. As a piston my be sticking due to old fluid.

 

[My Old Landy]

My wife has a Kuga and recently they changed the brake fluid as she said the brakes were dragging. I just asked her and she says the problem has gone away

 

[Keith 66]

Round here they just get stolen. Especially the newer keyless ones, seems like theres a post on the local fb community group every night of another one nicked of a driveway.

 

[prepman]

I’ve had mysterious rubbing calipers before - turned out to be the flexi hoses collapsing inside and acting as a one-way valve. Check for residual pressure by cracking the bleed nipple.

Diagonally opposed problem does suggest ABS unit, though. Is your brake fluid nice and clean? Moisture will cause corrosion.

Brake fluid will not be more than 2-3yrs old when the ABS was removed for repair. The rear calipers with built in handbrake mechanism is always suspect. They've been replaced. But that's why I suspect the ABS as it's not same axle. Hopefully not, as back then the ABS module repair was £700.
The car is 2009. Suppose I should get rid, but cars aren't my thing.

 

[m_c]

Could be a sticky master cylinder, or just coincidence that two calipers are sticking for some reason.

It'll need going back to basics. Check nothing is seized (pads in carriers, caliper slides, pistons). Then onto checking for any fluid restrictions.
Ultimately, it'll need time and somebody who isn't just guessing at what could be wrong.

 

[anto44]

Make sure the handbrake levers on the back of the calipers are returning to their stops when the handbrake is released. If the levers are held off the stops by the cables, when the brakes get warm it'll cause the calipers to start binding which will make them hotter and they'll binding even harder in a vicious cycle.

 

[prepman]

Could be a sticky master cylinder, or just coincidence that two calipers are sticking for some reason.

It'll need going back to basics. Check nothing is seized (pads in carriers, caliper slides, pistons). Then onto checking for any fluid restrictions.
Ultimately, it'll need time and somebody who isn't just guessing at what could be wrong.

As You say could be coincidence. That happens sometimes and gives misleading conclusions.
Unfotunately car won't fit in garage and tractor shed is very draughty. So not exactly inspired at present. The ABS module has an electric pump and sets of solenoid valves so master cylinder is almost the most simple part.
Knew I shouldn't have done the oil and filter

 

[prepman]

Make sure the handbrake levers on the back of the calipers are returning to their stops when the handbrake is released. If the levers are held off the stops by the cables, when the brakes get warm it'll cause the calipers to start binding which will make them hotter and they'll binding even harder in a vicious cycle.

Might be case with rear brakes but wouldn't account for front one.

 

[Brad93]

2009, time to get rid

 

[prepman]

2009, time to get rid

Hmm. 85,000m. Good bodywork. Underbody/subframes good. Electronics?

 

[prepman]

Round here they just get stolen. Especially the newer keyless ones, seems like theres a post on the local fb community group every night of another one nicked of a driveway.

Good idea....bring it round to your area and collect on the insurance....

 

[prepman]

Just thought there'd be someone here whose had this very issue and fixed it....ah well...

 

[mtt.tr]

Calling @premmington

 

[anto44]

Might be case with rear brakes but wouldn't account for front one.

I read it wrong. It's either going to be the abs unit or the master cylinder. I'd drive it again and then crack one of the bleed nipples and that should confirm there's pressure in the circuit, then give it another drive and crack the pipe at the master cylinder, if there's pressure at the pipe at the master cylinder then the master cylinder is holding pressure, if there's no pressure at the master cylinder then it's the abs unit holding the pressure.
Another thing I've seen happen once is a pipe between a master cylinder and an abs unit partially blocked with corrosion.

 

[m_c]

As You say could be coincidence. That happens sometimes and gives misleading conclusions.
Unfotunately car won't fit in garage and tractor shed is very draughty. So not exactly inspired at present. The ABS module has an electric pump and sets of solenoid valves so master cylinder is almost the most simple part.
Knew I shouldn't have done the oil and filter

Braking circuits on nearly all cars are diagonally split, with the dual circuits starting at the master cylinder, then split into F/R in the ABS module.
The ABS module only controls individual circuits, so it's highly unlikely to cause two circuits to hold pressure, unless there was a blockage on the master cylinder input.

However, it's far more likely to be coincidence.
Pads/Calipers seize all the time, and just because a caliper was only replaced 12 months ago, doesn't mean it's not failed/seized (especially if it's some of the reconditioned junk certain suppliers sell).
So I'd always start with the basics.

 

[anto44]

If you can get access to one of these type brake bleeders there's a few tests you can do which will help get this sorted

 

[tom2207]

thought the days of split , diagonally split brake systems was long gone ,,, sort of went out with Cortinas , after that its the brake abs / traction control unit that governs what goes where , ie the unit brakes the one wheel without traction on its own , not two as if they were diagonally split on the same circuit . There are so many acronyms in breaking / suspension now its hard to keep up. Then again you do see dual cct master cylinders and reservoirs , so there must be a split in it somewhere maybe a systematic diagram would help decide what goes where and does what ,,,

 

[anto44]

Most abs systems still operate a diagonally split. Master cylinder has two outputs to the abs unit, one feeds each circuit,