How to get new brake piston in... Any tricks?

[Jso123]

After viewing threads... Getting the old one out was easy.

Now ..with new seals, new piston , everything lubed with brake fluid, the dam thing will only go in 7/8 " and stop.

Any suggestions like heat or a shop vac to suck that thing in? I was told force beyond hand preasure should not be needed

Confirmed that new parts match old parts..

 

[Jso123]

Nevermind, finally got it in. Swearing definitely helped... But also used a small piece of PVC pipe in side the piston to get more leverage pushing it in...

Side question... While screwing with it, I stupidly got a few tiny scratches on the piston from a pipe wrench. Is it important to try and polish them out before proceeding?

 

[16VGTIDave]

Any imperfections in the sealing surface of the piston (basically the outside of it) can cause binding in the bore of the caliper. Worse yet, scratches on the piston may damage the seal and cause it to fail. Usually at the worst possible moment...

 

[Jso123]

Kill joy!

 

[16VGTIDave]

The truth may hurt, but it hurts much less than a lie...

 

[Noodles]

Holy crap! Putting my piston in and running into the same problem! And damb I don't have any tools with me like c-clamp. I think carefully using a c-clamp would be the best bet, but by hand....holy crap!!

 

[xschris]

Lube with brake fluid and make sure the bleed screw and hose is out/off. It should slide right in. Make sure you have the correct piston and seal. There are two different ones for the sohc xs400.

 

[Noodles]

I know for sure it was all correct parts and I was being very careful to push piston in evenly...unless you have hands of steel and was born on planet Kripton you would not get that piston in with hand strength alone. There's no "it'll slide right in" ain't happening. Use a c-clamp CAREFULLY! PUT EQUAL PRESSURE AND IT WILL SLIDE RIGHT DOWN TIGHT. throw the dust boot on and call it a day.