Rear brake pads & discs, Altea/Leon Mk2

[JoeF]

Can anyone advise please.

I have today changed one side, only took 3 and a half hours. That piston is a pain in the arse to wind back in. That took almost 2 hours. However I think I have a problem as the seal which sits around the piston come out when I retracted the piston with the brake pedal. I have managed to screw it back in but the seal seems to be sitting on the end rather then doing its job of sealing.

I have put the pads on and refitted the calliper. Put the wheel on, handbrake seemed very very loose so I pumped the brake pedal and it stiffened up again as did the brake pedal. I then reversed backwards and drove forwards testing the brakes. Seemed to work fine, very keen which is a good sign.

However there seems to be fluid coming from the piston still. Is this normal or will this be because the seal is not on properly? Or is it the built up fluid which is now coming out?

Don't want to drive and end up with no brakes.

Thanks

 

[RUM4MO]

It sounds like one of two things have happened:- 1) you have accidentally expelled the piston from the calliper far enough to go beyond the point where the piston/calliper fluid seal is - you do mention "using the brake pedal" it could be that the calliper and or piston is rusty and when you tried to get the piston back in it damaged that seal. or 2) you have a badly rusted piston that has scored the piston/calliper fluid seal while the rusted area passed the seal as you retracted it. If it was just the external dust seal that you had dislodged you would/should not have created a fluid leak.

Easiest way to sort this if you are not into refurbishing callipers, is to buy a new calliper from maybe ECP remembering that you will need to hand the old in eventually (soon) to get your deposit returned. That will require you to bleed the brakes etc. Consider that if it is " 2) " you might find the same issue with the other side?

Edited!

 

[JoeF]

Hi,

I did indeed use the brake pedal to release the piston, only because the wife's dad suggested i did this! To be fair though, there was no chance in hell i was winding it back in even with the tool as i could not fit the supplied metal plate in place as there was no room at all. I think the piston did come out too far as at one point i felt like it nearly fell out of the cylinder it was housed in. Various attempts to get it back in, some at really awkward angles i think has resulted in a damaged seal as it was a non stop leaking.

I have this morning done the other side and had no such problems. I managed to do it within 50 minutes, yesterday took me almost 4 hours. Aside from that, I have the handbrake light flashing at me even though the handbrake works fine and i have zero brakes along with a soft pedal which goes all the way to the floor. I suspect this will be no brake fluid in the system ???

Thanks

 

[RUM4MO]

Yes, I seem to remember that the "handbrake" light might also be the brake fluid level light.

The handbrake light, for that handbrake function only, is switched by the handbrake "handle" not being fully down, ie off. That switch is located at the handbrake "handle" lever assembly inside the car.

 

[JoeF]

I think Ill leave it to a friend who is going to come over at some point when he can, rather then start messing about with even more stuff and costing myself more

Oh well, aside from that one piston, it was pretty straight forward to change discs and pads!

 

[RUM4MO]

Maybe one tip to add here is, if you are in any doubt as to where the piston(s) might end up, always secure a block of wood into the space where the pads and discs normally reside - if you do that then you would never have ended up with not enough space to fit the rewind tool into. Just a tip, but too late for you unfortunately. I've never ended up with the pistons moving out on any car, but I did find one rear calliper on a B5 Passat and tricky to rewind when that car was about 10 years old, I think that I moved the handbrake lever on that calliper away from its end-stop slightly - and then I could rewind the piston.

 

[JoeF]

I'll bare that in mind for next time if I ever attempt it. Although when taking the calliper off the pads nothing moved AFAIK I put the tool in but there was no room for the metal plate. Do you think it could be because my pads were pretty much down to the metal?

 

[RUM4MO]

That is unfortunate, maybe I've always replaced the rear pads before they were really low in friction material thickness, but I've never ever had a problem having enough space to fit the piston rewind tool into - which is why I'd suspected, as mentioned in your opening posting, that you had pressed the brake pedal and had moved the piston further out than it would have been when you removed the calliper from the pads and disc. From memory, the rear disc thickness is never meant to get any lower than 9mm (starting off at 10mm) and each pad backing plate is roughly 7.5mm, that gives you 24mm to play with if the pads are worn down to the metal - which should be enough to fit the rewind tool in.

 

[JoeF]

Just to update, Its been confirmed I need a new calliper and will need to bleed the system and buy some new brake fluid as I have zero in it.

Don't suppose anyone knows what calliper it is as ECP list a few at different prices ranging from £70 - £100+ for mine. 57 plate FR tdi.

 

[The Captain]

Nice 'how to' guide.

Visit brakeboom.com or use the Mintes on-line catalogue for details of brake components.

I bought the Mintex brake box set MDK0037 (rear axle set of 2 x discs & 4 x pads) for my Ibiza - £33 delivered.

 

[Farqhuit]

Thanks for this, very helpful. Can anyone clarify two things for me (Leon mk2)?

1. Will a single right-hand thread tool do both sides?

2. Do I need to actually do anything to the handbrake actuator, other than making sure I wind the piston properly?

Thanks

 

[RUM4MO]

Right hand tool for both sides, nothing else needs doing except after completing this task, apply the foot brake firmly and then apply the handbrake a few times.

 

[Indieboy1]

Great guide thanks. I'm going to give this a shot soon bought new pads discs today.

Quick (maybe dumb) question.
Does the handbrake need to be released?

 

[verbal_kint]

Yes