[tramp]

hi all,

Right in the process of fitting new seals and pistons [2] , got old ones out and all cleaned up and new seals fitted and lubricated with clean brake fluid.

Now when trying and thats what it is "trying" offered up new and old pistons and push into caliper by using thumbs...... now they dont what to go past the "dust seals".

Is it a case off get the hammer and a socket to fit inside the pistons and gently tap them past the dust seal making sure their going in straight ,the calipers are on thebench detached from the hoses s.

cheers guys .... come inside for some wine to chill out before I totaly knacker something.

 

[Mervinh]

question 1 pistons, you did check they fitted before puting seals , if they did then it could be dirt in the groove the seal sits in make sure the groove is clean righ into the corners you may neeed to modify a small cheap screwdiver to get in to the front corner of the seal groove to get any dirt out.
merv

 

[tramp]

cheers MERV

tried the new pistons with the new seal fitted went in no probs , its just the dust seal thats causing the problem.

I cleaned the grove out "very carefully" as the bikes a 04 and used all year on/off road there`s years of crud in there , first replacement of seals since new bike so not bad.
Dust seals totally knackered and starting to fall to piesec due to salt probably, will wait for more suggestions but will probably be the "hammer option".

 

[StumpyFingers]

When I did mine I had to make sure the seals were flat.
One of the seals did have a slight twist and this stopped the piston sliding in.
Run a rod around the inside of the caliper flat against the edges of the seals, this should help square the seals in the grooves.
The piston should then slide in with a slight resistance.

 

[tramp]

cheers stumps,

i`ll have another look tomorrow and find a tool to fit the dustseal grove , thinking along the lines of a small allen key etc.

Did the piston just push in by hand with slight resistance?

The seals went in okay and are not twisted sounds like they are a little proud of the surface... Dawn corrosion we should all live in a hot dry climate

 

[StumpyFingers]

cheers stumps,

i`ll have another look tomorrow and find a tool to fit the dustseal grove , thinking along the lines of a small allen key etc.

Did the piston just push in by hand with slight resistance?

The seals went in okay and are not twisted sounds like they are a little proud of the surface... Dawn corrosion we should all live in a hot dry climate

An allen key will do.:thumbup:
I used a plug socket for its length, and just applied a downward force, with the caliper on the bench, a little brake fluid was used for lubrication.

 

[piguglyshandydrinker]

Tramp, sounds like you have done everything right so far.....
Ensure the seal is snugly in it's seat, plenty of brake fluid on the piston & seal & gently work it in, maybe a little wobble from side to side to work it past the seal.

Whatever you do - don't hammer it, this is one (of the few ) situation where you could really bollox it up with brute force & ignorance


Phil

 

[PaulScar]

I have always used a small carpenters G cramp for this job, make sure the pistons fit without seals, polish with brasso or solvol autosol if needed, clean the seal groove well, fit the seals carefully then press in square and gentle.

 

[tramp]

cheers all ,

sounds like there still some crap in the dust seal grove ...

phil - it aint the hammer thats the prob its the "fool using it":withstupid:
suppose this is a "measure twice cut once situation"

 

[awsi4u1]

why dont u put the piston in the freezer for some 15 min and try again

 

[AlanH]

sounds like there still some crap in the dust seal grove

That would be my guess too. They should go in with firm thumb pressure. If they don't then the seals are not seated right.

 

[tramp]

Hi all,

cheers for all the support its what makes this site special.....

Brakes know sorted and better than ever ..