Excessive front brake lever travel; pistons stuck in bores

[Dan89flstc]

Can you tell more about the circumstances the Wilwood GP-310 seized...

I`m not sure what caused the issue, but I changed over to DOT4 fluid, and I think when I flushed the system I didn`t get it all out (I have since gone back to DOT5 for this old bike).

There was no physical damage or wear on the bores, once cleaned they looked like new, so I think the seals swelled up big time.

When I rebuilt the caliper I also replaced the master cylinder (I was upgrading to later model controls, switches etc), and also installed a new brake line. It works fine now, finally after 30 years the old Softail actually feels like it has brakes...

I just installed another Wilwood GP-310 on the rear.

I found the folks at Wilwood to be very responsive to tech questions by phone.

[14Frisco]

Thanks Dan.
When I replaced the OEM caliper w/ the GP-310 I decided to stick w/ DOT 5 since it had worked fine over the years and is not/less harmful to paint.  I also stuck with the OEM 5/8" master cylinder although a smaller-bore would be better to get a less-woody brake lever feeling.

Sorry for the thread hijack...

[Ratfade]

Returning briefly to the topic, everything is back together and working great. Super advice from everyone here.

[Hossamania]

Glad you got it, I'll bet it's nice to have good lever feel back.

[Ratfade]

It's great to have it working well. When I got it back together, I did notice that the brake light stayed on. So I went with my usual fix which is to build a little extension for the lever tab that keeps the "off" switch depressed. I use epoxy and a tiny piece of 3/8 in. OD tubing to extend the tab.

[Dan89flstc]

Glad you got it, I'll bet it's nice to have good lever feel back.

What did you do to correct the problem?

[Hossamania]

Glad you got it, I'll bet it's nice to have good lever feel back.

What did you do to correct the problem?

He rebuilt the calipers.