Kinked Steel Brake Tube (maybe), brakes frozen

[ScooterMD]

While replacing the brake caliper and pads, when I had the caliper removed from the knuckle and hanging from a bungee, it twisted around and it looks like it may have kinked the steel tube connected to the caliper.

After reconnecting the caliper and bleeding/pumping the brakes, this caliper's pistons appear to be frozen, such that turning the rotor is extremely difficult. The other rotor/caliper is totally fine.

Although it's possible the new caliper is frozen/defective, I suspect the steel brake tube may be essentially compressed/collapsed internally, such that, once the pistons are pressurized by pumping the brakes, that pressure is trapped inside the pistons, keeping the brakes pads compressed against the rotor. Has anyone seen this before?

I tried opening the bleeding valve and it does make turning the rotor slightly easier. Before I just go and buy a new steel tube and restart the process of bleeding, was wondering if this is something other people have encountered. That is, whether a kinked steel brake tube will disallow the brake pistons to release pressure, thus keeping the pads compressed against the rotor.

Thanks in advance.

 

[maxdef]

I don't know for sure if it did fail, but I do know that both sides are very inexpensive and you should just replace it. I did and I'm pretty sure it added either +5hp or -5 brake time.

Tube | Part #4731435320 | Toyota Auto Parts

Front Left/Driver: 47314-35320
Front Right/Pass.: 47316-35320
(Short end is caliper side)

 

[ArthurKotb]

I think you have diagnosed your problem. The bent brake line is probably preventing the return of the fluid. Your applying more pressure with the pedal to energize the caliper than will release on its own. If you can just buy the formed brake line then that's the best solution.

 

[AuSeeker]

I think the line should be replaced....but I don't think it's the issue, if it was then when you opened the bleeder valve the rotor should of turned freely and you say it only slightly got better, that tells me that either the piston is seized or the guide pins need to be lubricated or both.

 

[MikeinNH67]

I think the line should be replaced....but I don't think it's the issue, if it was then when you opened the bleeder valve the rotor should of turned freely and you say it only slightly got better, that tells me that either the piston is seized or the guide pins need to be lubricated or both.

+1 It doesn't look kinked enough to me to completely stop the flow back and these trucks are notorious for bad calipers but yours is new. Do make sure the pads move freely on both sides of the disk.