Menu
What's new
By:
Advanced search...

Pad change

O

OB1

Members
Messages
932
Reaction score
21
Location
S Yorks
Car
05 diesel saloon
I've just got my hands on a copy of the Haynes Brakes technical manual. In the section on changing pads, it states (as has been said many times before) that simply pushing the pistons back into the calipers can damage components such as ABS sensors or the seals in the master cylinder. They suggest (lightly) clamping the flexible brake line and opening the bleed screw on the caliper so excess fluid can be drained off instead of being pushed back through the system.

I was just wondering if anyone does this or do you all just push the pistons back and hope for the best?

Also, given the common 7th gen problem of the rear flexible brake lines breaking down, does this seem like a sensible idea? I'm thinking that not clamping the line but just opening the bleed screw would be enough. What's everyone else's opinion?
 
I've been clamping the hoses on my 6th Gen. I press it back with a Irwin XP Quick Grip so you can single-handedly control the piston and caliper whilst operating the bleeder at the same time.
 
I didn't bother. Plus I used my bare hands... :p
 
I've always removed the reservoir cap and been fine, if doing the haynes way you risk introducing more air into the system which will obviously need to be bled which can be a ballache in its self. Hassle if only changing pads imo.
 
TBH I like the idea of not shoving a whole load of brake fluid that has been sitting around the caliper back-up into the system. So I normally, just open the bleed screw and attach a tube. With it open the system should start to bleed itself (slowly). Then by pushing back the excess fluid falls into the collection container and not back up the pipework, when you see the state of the fluid, you'll be glad you did.

As for the rear hoses on the tourer, I would think this is even more of a reason not to shove the gunk back?
 
Well considering the same manuals advise you not to leave the calliper hanging by the brake line in case you split the pipe I wouldn't go clamping the pipe for that exact reason. If you don't split the outside of the hose you may well spit the inside, given how susceptible the rear hoses are to this, which will cause brake binding at the least.

Personally I've always just removed the lid off the brake reservoir and very gently (not to blow a seal) pushed the piston back in with a clamp.

If pushing the piston back in causes a problem with the sensor that would be due to a fowling/ tolerance issue between the piston and the sensor. In that case it wouldn't matter what method you used, clamp or bleeding, you would still be at the same risk of it happening when you pushed the piston in. So I don't see how using one method over the other would reduce the risk of it happening.

On the rears though I would suggest using the wind back tool.
 
Some good feedback guys, thanks. I've not heard of anyone on here damaging a master cylinder but there definately seems to be an issue with hoses degrading so I think I'll keep on pushing the piston in without clamping the hose. I'm tempted to bleed the excess fluid off through a visibleed though. That way there'll be less chance of forgetting to check the reservoir and ending up with brake fluid pouring all over the enigne bay!
 
You must log in or register to reply here.
Top