Brake pedal creep

[DiscoStu]

Hi all.

I've changed the front brake pads on my '94 Disco this morning. No issues when doing the job, everything very simple as you would expect.

Before the change my pedal was really good. Firm, not too much travel etc.

Now its creeping to within an inch of the floor when constant pressure is applied and I've not much stopping power either.

Anyone got any sugestions why this problem has arisen all of a sudden, and how to remedy it?

Stu.

[scooby]

ello stu

here we go :- have you bought cheap and nasty pad's ? i have and they where sh*te

if not if you pump the brake pedal will you get a good hard pedal if so your pulling in air, worth giving them a bleed

this could have entered at the piston seals ,

if not it could be the master cylinder gone duff a good rule of thumb check your fluid if it is looking dirty

your seals will have started to perish , all the above have happened at different times when changing pads

hope this is some help mate

ps check flexi-hoses and brake pipes in case any damage caused by accident

[Les Henson]

As Scooby says - if you pump up the pedal and it stays hard without creeping, then you have air in the system - although changing the pads won't do that unless pushing the pistons back in has caused a leak. If you pump it up and it still creeps down, then it's likely you have a weak seal in the master cylinder. You can get repair kits for the master, so no need to fork out £80-odd quid for whole master cylinder.

This thread is for a 90 master cylinder, but the method is the same for a disco.

http://forums.lr4x4.com/index.php?showtopic=5300

Les.

[DiscoStu]

Cheers guys.

Pads were Apec, from my usual motor factors at £19.00 per set so dont appear to be cheapo's. (I hope!)

Pumping doesn't firm the pedal up, it still creeps. I'm thinking it must be servo/master cylinder but I'm gonna try a bleed first cos thats the cheap option.

I have noticed that I can see a lit bit of "bubbling" at the rearmost down pipe of the resevoir where it joins the master cylinder. Only when a bit of pressure is applied to tilt it though, not when pressing the brake. (I don't think, its hard to see).

Thanks again.

Stu

EDIT: I just re read what you said Scoob, I was surprised at how filthy the brake fluid was. I replaced rear axle, brake popes and rear flexi hose a couple of months ago so a lot of that fluid should be pretty new.

[paintman]

And don't forget that the new pads will take a couple of hundred miles to bed in to the discs which in itself will make the pedal less firm than it was before.