New Calipers, Duds?

[tima01864]

Bryan,
I removed the piston from the old caliper, Needed a good cleaning inside. Now I can not screw or install the piston in the caliper. CCW nut locks CW nut spins. The new caliper I screwed it out and reinstalled no issue. Any help here? Okay this is over for me, I removed the square o-ring, Then the piston screwed back in, The old caliper behaves the same as the new caliper, In conclusion the new calipers are okay seemingly. Now to get the handbrake working

Tim

[18Fiatsandcounting]

Tim, check the e-brake cable tension on both sides. Sometimes one side is goofed up (sticking or otherwise binding), and so all you're doing when pulling the emergency brake lever up is taking up the slack in the cable, but not moving the levers on both calipers in equal and sufficient amounts.

-Bryan

[tima01864]

Strrange tho, I had the brake working once by doing that, tugging at the cable getting it centric. Then held only for a short time, I noticed the new caliper only pushes the piston forward at full travel of the lever. I will keep at it, I just e mailed A different vendor if he can guarantee me a new set will work. Otherwise I will look around for a rebuilt set. I would try to rebuild the old but the bleeder snapped off.

[18Fiatsandcounting]

You mentioned a square o-ring, and at first I couldn't picture that, but it occurred to me just now that I think you mean the main seal between the body of the caliper and the outside of the piston. This seal fits in a groove in the wall of the caliper bore, and is a little over an inch in diameter.

Note that the hydraulic part of the brakes won't work without this seal, as brake fluid will just leak past the caliper bore and piston when you press the brake pedal. It can be hard to insert the piston with this seal in place, but the solution is that the seal and piston outside should be heavily wetted with brake fluid before trying to insert (screw) the piston back into the caliper.

-Bryan

[tima01864]

Understood Bryan, Could not get the piston passed the o-ring, too dry, So for the sake of seeing how it works I took it out. Careful not to scratch the aluminum seat.

[18Fiatsandcounting]

Understood Bryan, Could not get the piston passed the o-ring, too dry, So for the sake of seeing how it works I took it out. Careful not to scratch the aluminum seat.

That what I figured, just checking! When you reinsert the o-ring seal, use lots of brake fluid as a lubricant, and insert the piston with a twisting motion back and forth (CW and CCW) until it engages the threaded end of the actuator rod. At that point, you should be able to take a large flat-bladed screwdriver and, using that channel in the face of the piston, screw the piston down onto the actuator rod. Clockwise if I recall.

-Bryan

[tima01864]

Pulled the drivers side caliper, Actuated the lever on the caliper, It does not act on the piston. No action so safe to assume it is a bad or miss assembled caliper. Probably mis assembled, I really dont want to take the time to disassemble them.

[spider2081]

No action so safe to assume it is a bad or miss assembled caliper.

I just checked a spare one I have. Moving the arm full travel (by hand) the piston moves out about 1/6 inch. definitely a visible amount of movement. If your does not move like you say something is wrong.

[tima01864]

Yes, The old caliper moves the same amount about a 1/16th+, There is no movement on the caliper on the car. I dont want to rebuild them, Will have to source a new pair, First off Fun Imports new or rebuilt. Hate throwing money away but this is a safety issue, Nothing wrong with the car or how the calipers were installed, Whew. I could call the vendor as suggested but it has been a year or more doubt the vendor would consider an exchange.

[tima01864]

A little history, When I got these new calipers I could not bleed them. In my frustration I called the vendor and asked for a new caliper. Never sent the old one back, Got charged for it. The middle rear brake hose was collapsed, that is why I could not bleed them. So I have the new caliper, Took that apart, Bellville washers were not in the right orientation and there was not a flat washer.

[18Fiatsandcounting]

Sorry folks, I'm starting to lose track of where we are on this issue... On your new calipers, it sounds like you have correctly oriented the 5 Belleville and 1 flat washers so that they are ()()(|. On your workbench, actuating the handbrake "arm" on the calipers moves the piston outwards about 1/16" and then the piston retracts when you release the arm. OK so far?

However when in the car, the handbrake lever does not actuate the lever on the calipers, and the emergency brakes do not work. The hydraulic part (brake pedal) of the system works as it should on all 4 wheels. Am I correct on this?

One question at this point: With the rear calipers installed on the car, but with the brake cable not connected, does actuating the arm on the caliper have any effect on the brakes? If the wheel is off the ground and you spin it, does actuating that lever cause the spinning wheel to stop abruptly?

-Bryan

[tima01864]

Bryan,

I explained a little above why I had a new caliper from the same vendor. This morning I raised the axle, Wheels off. Loosened and detached HB cable from left and right calipers, Stuck a screw driver in the lever pushed it to end of travel to no effect. I then took the caliper off and doing the same observed no movement in the piston, Cleaned them up and lubricated the contact pointswith permatex ceramic brake lube. Did the same to the otherside. Reinstalled the HB cable and adjusted it, Three clicks on the lever. Took it for a spin, Still no E brake.

Referencing the caliper off the car,As I would assume they are the same, Bellvile washers not assembled as you have shown, missing a flat washer so 5 bellville washers. Too much work to take the caliper off the car and check it out as I have a new one from the same vendor and probably the same lot.

To this extent I think the calipers are not right, The cable is new and the routing is clean.

Tim

[18Fiatsandcounting]

Tim, thanks for the additional info. If actuating the e-brake arm on the caliper does not move the piston at all when the caliper is out of the car and on your bench, then it also isn't going to work when the caliper is installed on the car.

The Belleville washers are there to pull the piston back into the caliper (away from the brake pad) when you release the actuating arm, otherwise your brakes could continue to drag even after you release the handbrake lever in the car. I've never bought new calipers (always rebuilt my old ones), but I have heard that new ones sometimes come with the Belleville washers installed incorrectly.

I know you don't want to hear this, but it still sounds like something is wrong with the actuating rod/nut/roller bearings/keeper plate/spring inside the piston. You could try another new caliper from a different vendor, and I would definitely check that the actuating arm moves the piston in and out as it should, before installing on the car. Or continue to tinker with the calipers you have until you get it straightened out.

Keep us posted.

-Bryan

[tima01864]

Exactly

[spider2081]

No action so safe to assume it is a bad or miss assembled caliper.

I just checked a spare one I have. Moving the arm full travel (by hand) the piston moves out about 1/16 inch. definitely a visible amount of movement. If your does not move like you say something is wrong.