# Knock-back springs in stock '67 disc brake calipers?



## ragtopgoat (Sep 26, 2019)

I just bought my '66 GTO 6 months ago and found that the front brake calipers were leaking brake fluid, so I replaced them with rebuilt units from Ames (the car was upgraded to the '67 front disc brakes by the previous owner). I was surprised to find that the pistons in the brake calipers appear to have knock-back springs? In any case, I am finding it very frustrating to install the brake pads, as I can't get the pistons to retract and stay out of the way. I have to hold them in with a tool while I slip the edge of the pad between the piston and rotor. The piston also "floats", meaning it doesn't push in evenly, making it more challenging to push it out of the way. This needs to be done for each piston to slip the pad in place. Previous cars I've worked on, this was never a problem. Once the pistons were pushed back in to their bores, they would stay put, allowing the brake pad to be slipped in. What am I missing here? Is there a trick to changing the pads with these '67 stock calipers?

Thanks in advance for you help!


----------



## PontiacJim (Dec 29, 2012)

ragtopgoat said:


> I just bought my '66 GTO 6 months ago and found that the front brake calipers were leaking brake fluid, so I replaced them with rebuilt units from Ames (the car was upgraded to the '67 front disc brakes by the previous owner). I was surprised to find that the pistons in the brake calipers appear to have knock-back springs? In any case, I am finding it very frustrating to install the brake pads, as I can't get the pistons to retract and stay out of the way. I have to hold them in with a tool while I slip the edge of the pad between the piston and rotor. The piston also "floats", meaning it doesn't push in evenly, making it more challenging to push it out of the way. This needs to be done for each piston to slip the pad in place. Previous cars I've worked on, this was never a problem. Once the pistons were pushed back in to their bores, they would stay put, allowing the brake pad to be slipped in. What am I missing here? Is there a trick to changing the pads with these '67 stock calipers?
> 
> Thanks in advance for you help!



From what Has been said about the 4-piston calipers, they are the same as the Corvette.

So, looking for Corvette info, there is a tool that appears to clip over the top of the caliper and hold the spring loaded pistons in place for brake pad installation or removal; 1965-1982 Corvette Disc Brake Piston Retaining Tool

Gives you some idea as to what you may be able to fabricate in sheet metal if you don't want to buy the tool.


----------



## ragtopgoat (Sep 26, 2019)

Thanks PontiacJim, that's exactly what I've been looking for!


----------

