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Hayes 9. Can't get pistons to set in the back of caliper.

Freeridin'

Monkey
Oct 23, 2006
316
2
Colorado
Went to replace the pads on the Hayes 9s. Usually I take the pads out and push the pistons all the ways back until they are flush with the caliper. The pistons won't retract far enough and the pads are too close to the rotor.

I've used lots of pressure and they still are too close together. Would bleeding them fix this issue?
 

zebrahum

Monkey
Jun 22, 2005
401
0
SL,UT
Are the pistons perfectly straight? Get a flashlight and check before you go pushing anymore. It should never take a large amount of force to push pistons back in. If they appear to be straight, flip the lever so the bleeder is straight up, take out the block and then go back to gently prying the pistons apart. If they still don't go in straight, you might need to blow out the pistons, clean them, and put it all back together and bleed it.
 

mellow_sparky

Monkey
Aug 21, 2009
133
0
Washington State
sometimes they are slow to push back in, but they should go all the way back. i had a similar issue and the tech from hayes advised to slowly pump the pistons out - not all the way, but quite a bit. then use a Q-tip to rub DOT4 around the edges of the piston to help lube it. then push them back in.
 

ultraNoob

Yoshinoya Destroyer
Jan 20, 2007
4,504
1
Hills of Paradise
Figured it out.

Turns out there was a little too much fluid in the line.
Happened to me a while back when I did my very first brake bleed. I bled the brakes with the old pads on. After I wore out the pads, I went to put new ones and I couldn't get the pistons to go in all the way. Bled them proper and I was kosher.
 

Snowflake

Monkey
Aug 10, 2009
170
0
Maryland
I was just joking around =)

-Ms. Brokeass (That is extremely lucky to wind up with saints, after running hayes 9 for the last year.)
 
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