Crap brakes

[3VILC]

So the brakes on the terrano are getting pretty crap and need sorting asap. Seems to fade real bad and pedal can be pressed to the floor if pushed reasonably hard. Repeated pumping doesn't build up any more pressure or firmness and the 'brake' light flickered momentarily when I was pumping it today. Air of course is the obvious answer but where from? Doesn't seem to lose any fluid and has never run low and no obvious leaks. Front pads are ok discs are a little worn down and could probably do with replacing but should still be clamping fine. Can't see any traces of fluid around the bottom of the drums but suspect shoes are stuffed. Can drum cylinders suck air without actually leaking a noticeable amount of fluid?
Any other ideas what to start pulling apart before I buy a heap of parts I don't need haha

[Crash bandicoot]

master cylinder seal kit time.

[derk]

realistically you need to strip it all down and do a brake service on the thing if the brakes have got that bad mate, check the condition of the pads and the shoes if its got drums on the back, make sure all the calliper and wheel cylinder pistons are free and not seized, uneven pad wear is usually a sure sign of seized pistons, check the condition of the hoses and preferably check them while someone's standing like fawk on the brake pedal to see if you've got any bulges developing under pressure (fluid and pressure should be traveling down the hoses not expanding outwards ) check the operation of the booster and vacuum and the condition of the M/C as already suggested above if its got a proportioning valve attached to the rear axle make sure the linkage is adjusted properly and its functioning correctly you can use a pair of vice grips to clamp off brake hoses to try and isolate the problem to front or rear brakes

[3VILC]

Arg don't say that lol. Suppose that's a p##ck of a job with abs. Makes sense tho unless I find a leaking wheel cylinder, the master isn't pushing much fluid

[3VILC]

A bit of reading seems to agree that the drums are crap and can cause trouble when worn. They have probably had a hammering with a few (too) heavy loads on the back so first port of call will be to pull those down and see whats going on in there, never been adjusted either so likely a good cause of a low/soft pedal? Didnt realise you still needed to manually adjust drums this new

[catalystracing]

Have the same problem with my hilux drums, just manually adjusted the auto adjusters , all good now

[3VILC]

The shoes I'm sure are pretty knackered so will pull it all down get some new shoes and see if the drums need replacing too, probably just get a good 2nd hand pair to have on hand when I do it just in case. See if that makes any improvement. New discs and pads are on the shopping list anyway but still appear to be serviceable. Given the amount it nosedives if you give the pedal a reasonable stab I'd say the front is doing most of the braking