# Brake troubles on a '67...again and again!



## daveh70 (Sep 4, 2008)

Anyone else have such issues with the original 4 piston caliper on the '67? 

Having a '67 with the special optioned 4 piston caliper disc brakes is neat. But this is getting expensive. After replacing a proportioning valve, hub/rotor assemblies (the original 2 piece units aren't made) brake pads (also tough to find as so few carry them) among other things, now the caliper seized and needs replacing. I located rebuilt ones. They don't come loaded so I had to find pads too. Just wondering if troubles with these brakes on a '67 is common.

Dave


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## geeteeohguy (Feb 2, 2008)

Not really. What happens is, brake fluid absorbs moisture out of the air vaery well. If the car sits, and is not used, calipers, wheel cylinders, etc. tend to rust from the moisture in the fluid and it seizes things up. Driving the car gets the fluid hot, and keeps the fluid and parts in better shape. Siezed calipers can be rebuilt. I've done it many times. With Corevettes, corrosion is common (high Lot Rot rate) , and stainless steel sleeves are commonly fitted to the inside bore of the caliper. Just keep the brake fluid fresh, dont' use Dot 5 fluid, and drive the car. You should be OK. The only thing "wrong" with the 4-piston set-up is that they were rare, due to public ignorance of disc brakes at the time, and therefore they are $$$$ now, 42 years later. Techinically, they are better than single piston brakes. All the hi-po Baer, Wilwood,, etc. brakes are 4 piston or 6 piston.


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## daveh70 (Sep 4, 2008)

*why not DOT 5*

Why not DOT 5 fluid? DOT 4 was used previously.


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## Jstreet (Mar 9, 2009)

Short answer:

Dot 5 is a silicone fluid. The seals in your system were not designed for that setup and you will have failure/leaks.


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## geeteeohguy (Feb 2, 2008)

Also, Dot 5 should not be used for another reason: It is not as forgiving with moisture as dot 3 or 4. Moisture gets into the system and doesn't ablsorb iinto the fluid, causing water pockets and rust problems. For this reason, cars with Antilock brakes never use Dot 5: it ruins the modulator valves. Dot 5 is good for one thing only--high boiling point on a race course. Dot 3 regular is more than adequate.


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## daveh70 (Sep 4, 2008)

Thanks. Does that go for a '64 on all 4 drum brakes? Use DOT 3 or 4 on that?


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## geeteeohguy (Feb 2, 2008)

I use DOT 3 on all of mine.


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