Really Really Really weird brake problem

[masterbateson]

Went out for a spin today as its 1st time its been dry for ages

Anyway something really weird happened, we had just pulled off after me and the lad had stopped for an ice cream, set off up the road built revs up and then planted it and something really weird happened.
Car hesitated and i thought it had blown a hose off, got out took a look and no signs of a hose of or a leak.
Tried to move off and cars hardly moving and want to conk out, so i put car in reverse and she moves back ok
so I reverse back into a little pull in layby thing.

Its then I notice that the Brake pedal has gone absolutely solid, it wont budge a mm never mind an inch.
When i check it seems like wheels/brakes are locked on.
Now the funny thing is, when we set off the brakes were a little spongy,I have been trying to bleed one calliper thru the hose as brake nipple is snapped off on that one.
So somehow gone from brake feeling a bit spongy to the brake pedal going so hard you cant depress it and possibly all brakes locked on?

In the end had to get my mate to recover me on his trailer.
Now this is when it gets really weird, his trailer tips up really steep so I jump in the car when i get home, start her up and as she moves off in the 1st few inches, we both swear we heard like a clunk, and hey presto!! suddenly my brake pedal has gone back to normal? and the brakes work as normal.

What on earth has gone on? whats up with my brakes?

[Martin F]

Brake caliper missing a bolt ? Brake pad worn and stuck on disk ? Part fallen off ? badly worn discs ? something happened to the piston ?

You need to take the wheels off and strip down the brakes and figure out what has gone wrong.

I sold an audi A3 a few months ago, just before I sold it I was driving along, tried braking only for the pedal to hit the floor and hear a clunk. The inside part of the brake pad had fallen out leaving the metal part to go directly to the disk, so anything's possible...

[masterbateson]

Talk about being a glutton for punishment had been playing with boost hoses and did a few tests on brakes all ok in the garage.

Went out for a run and sure as eggs are eggs it did it again,but on the plus side because it was dark it helped show up one thing Bloody brake disk on passenger front was glowing cherry red, went back and checked the pedal and absolutely solid.

Anyway this time i got on the go a bit quicker and without the aid of a mates trailer.
I let the disk cool a bit,then cooled it a bit more by taking a waz on the offending calliper and disk.

Think i need a refurbed calliper or a rebuild kit, think if i go down rebuild route i will order for all 4 corners.

Why oh why are these cars callipers so Sh1te!!!

[tiff_lee]

Remove the caliper and give the slider pins a grease, also be worthwhile having someone else on hand to pump the brake pedal while removed so you can see if the piston is seizing, cycle it a few times.

[masterbateson]

Wish it was as easy as sticking sliders
Its def sticky pistons.

Wheres best bet for refurb kit?

And when you get it, is it easy enough to get dust boot in? I am a bit feared by the metal retainer ring.

Cant seem to find a good how to with picks that shows the removal and refit of this piece.

I can do the strip down to point pistons are out, but dont know if i need some sort of special tool to get old seals out and more importantly new seals back in place with this metal ring.

[tiff_lee]

http://www.biggred.co.uk/

is probably the goto place for refurb kits.

Not done an MR2 caliper before but it's all pretty straight forward, the metal retainer ring just clips around the outside of the dust boot to hold it in place. The actual piston seals are just a rubber seal sat inside a recess in the caliper come out/go in easily just have to be gentle when refitting pistons so not to 'pinch' the seal.

[masterbateson]

Well despite the cold, i decided to brave the garage and have an inspection.
Wheel off calliper off and nothing obvious.

So i pumped the brake and out the 2 little blighters came
Any way seeing as i had the calliper off I got my big stilson pliers and compressed each piston back in one at a time, squeezed one in other came up, squeezed that one and the other one popped back up
Any way I did this over and over for a while, also turned the pistons round a few times whilst doing my up down in out piston workout.

Anyhoo slung it all back together and went for a spirited run, with some emergency stop braking down a closed road, all good! No red hot disks.

Next job is some new boots as tyres are a bit shot at, and some new pads as the ones on the front are almost down to the metal, well 2 or3 mm worth, but not enough for my liking.
Think i deserve a drink tonight.

[mouley1989]

Very similar thing happened to me...

After a very hard stop, my brakes seemed like they were sticking on, then they suddenly released... happened a couple more times in the following few weeks...

I changed my master cylinder which solved the problem... cost me £35 from eBay breaker...

May be worth a try?

[masterbateson]

ta 4 suggestion but found the prob already as in the post b4 yours