300tdi disco brakes issue

Hi guys,
With all the recent wet weather I had a few close calls with skidding front left wheel sometimes locks up coming to lights and stops. I don't know if it's the tyres or brakes ? ? My tyres are half worn 15 km .
Did some emergency stops on private lanes (testing) and I feel sometimes my front left wheel locks up prematurely whilst rears wheels roll on. This happens on dirt road . But on grass the rear wheels do lock up.
Could it be the equalising unit ( whatever the term is ) under the windscreen washer bottle ?
Is there anyway of testing this unit
Should I just buy new tyres at 500 euro or swap the equalisingu unit ?
Any opinions appreciated

First thing i would do is check all brake calipers and pistons are free.
The front brakes do tend to do most of the work you may have noticed front pads wear out quicker than rear ones.
Start with cheap fixes first, drive a mates dico and compare, could be very hard compound tyres

Mark Ormond said:

First thing i would do is check all brake calipers and pistons are free.
The front brakes do tend to do most of the work you may have noticed front pads wear out quicker than rear ones.
Start with cheap fixes first, drive a mates dico and compare, could be very hard compound tyres

Click to expand...

true, rears tend to seized pistons and rusty discs through lack of use

Got a set of bfgoodrich tyres and much improved braking now on wet roads.....A good investment. The rear pistons are free , but I noticed the discs are little rusted and pitted , I will replace.
Thanks guys for suggestions.

Stick it in for an MOT to identify the problem area.
Had the same on my old Disco, rear calipers had seized.

My rear calipers were crap, but repeatedly passed the MOT! I took them apart and gave them a clean, then fitted some new pads and the difference was exactly like going from front only brakes, to all brakes front AND rear - Now it stops amazingly well!

The symptoms were exactly the same as yours - fronts locking up almost instantly, rears rolling and not locking. It gave me little confidence on wet country lanes, but not anymore. While you're back there doing the pads, bleed all the cruddy brake fluid out too as that can only help things.

I think it is worth fitting stainless steel pistons, especially in the rear calipers, as well as silicon brake fluid. After I overhauled the calipers, front and rear, with new seals and s/s pistons, with new discs and pads not only did the Discovery stop much better, but I found it rolled more easily. Seized calipers can cause brakes to rub as well as not offer much retardation. .

My vehicle was sitting up for two years until recently , so I'm sure that didn't do brakes much good.I will include news calipers when ordering new discs . I have already replaced the fluid.
Thanks to all.

Fitted new front calipers pads and discs , and the front brakes now pull equal and straight . So impressed I will next do rears calipers discs and pads,
Ta all