New Calipers, Duds?

[tima01864]

Spider2081 Would you have two usable rears that you would part with? Just thought of asking

[18Fiatsandcounting]

I know this is a long shot, but I'll just toss it out there in case it helps. In thinking about how the rear brake system works, I imagine it might be possible to get into a situation where the hydraulic part works but the emergency brake doesn't. Here's how.

Suppose you put your rear calipers back on, and they were fairly loose in that the piston wasn't tight against the pads (kinda how it should be actually). Then, before bleeding the rear brakes, you tightened the emergency brake cable, perhaps a bit too much. The e-brake arm on the caliper is now actuated, but since the piston wasn't against the brake pad, pulling up on the emergency brake handle in the car can only move the actuator arm just a bit further, but this just moves the piston closer to the point of pressing on the brake pad, but not enough to grab the brake rotor like it should. So your emergency brakes don't work.

So now you bleed the rear brakes, and they work fine, and the piston is now snug against the pad. But, since your e-brake actuator arms on the calipers are already partly (or mostly) actuated even with the handbrake lever off, pulling up on the handbrake lever doesn't do much. So, the hydraulic brakes work but the e-brakes don't.

Solution: Get the hydraulic part of the rear brakes bled and working right before you even install the emergency brake cable, and make sure that the actuator arm on the caliper is in the fully "off" position during this process. Perhaps even drive the car a bit to make sure all the pads are fully seating and working right with the brake pedal. Then install your emergency brake cable and tighten the adjusting nuts until there is no slack in the cable but the actuator arms (on both rear calipers) have not started moving yet. Then try the emergency brakes.

-Bryan

[tima01864]

I have one more thing to add, In May I brought my car to FunImports to have the rearend swapped out to a 3.9. I would bet my car Danny set up the brakes correctly and as Bryan laid out.

[18Fiatsandcounting]

I have one more thing to add, In May I brought my car to FunImports to have the rearend swapped out to a 3.9. I would bet my car Danny set up the brakes correctly and as Bryan laid out.

Ahhh, the plot thickens! Is there a chance the rear brake compensator was either bypassed, or isn't working right? I would think this would affect the hydraulic part of the rear brakes and not the emergency brakes, but maybe this is all tied together somehow?

The center rear rubber brake hose between the underbody and the axle goes through a metal line to this regulator (on the passenger side) where it then is split into two and goes to each rear caliper via metal lines along the axle, and a short rubber brake hose for the final 8 inches or so. Unless it's been modified of course.

-Bryan

[tima01864]

I had replaced the line going to the rear compensater, Which had recently been replaced by the PO, Also the rubber lines and three way tee.

[18Fiatsandcounting]

OK, I found something that might help. I have my '71 spider up on jack stands, as I'm just wrapping up redoing suspension, brakes, drivetrain, etc, etc. So I went out to check my emergency brake, and...

.... wait for it...

It doesn't work, not even if I remove the cable and actuate the arm by hand to its full travel. So, I'm thinking, "What the heck? Have I been hanging out with tima01864 too much??!! Durn his hide!!!"

So I take apart one of the calipers, and the circlip that holds the retainer plate in position inside the piston had popped loose. You might check yours, as apparently if this circlip is not installed correctly, the hydraulic brakes work and the emergency brakes don't. You could easily see how the e-brakes might work once or twice before the circlip popped out, such as you experienced.

The good news is that I fixed it, the piston again moves in and out as you actuate the arm, and I'm gonna head back out to the shop to put the caliper back on and check the other caliper.

-Bryan

[tima01864]

That does seem odd Bryan, Are they old or newly refreshed?

[tima01864]

I have to wonder how many owners have had a problem with the handbrake? Those I have or have responded say they have had no problems other than they dont work very well.

[18Fiatsandcounting]

Well, I put the caliper back on, and apparently the loose circlip in the piston was the problem. Now the hydraulics work fine, and one or two clicks on the emergency brake lever locks both rear brakes up tight.

The calipers are the original, and I rebuilt them about 30 years ago. Just recently, I rebuilt them a second time (cleaning, new seals, etc.). However, I must have installed one circlip incorrectly or not fully seated in its groove, and it popped out. The other side of the car was fine.

There is a reasonable chance that this is what's wrong with your emergency brakes.

-Bryan
PS When the emergency brakes are working correctly, pulling up on the handbrake lever should lock the rear wheels if you're driving along at, oh, 20 MPH or so. Don't try this at highway speeds of course!

[tima01864]

I have decided to replace these calipers of mine with refurbished calipers from a trusted vendor, I will pay dearly for them but peace of mind is priceless.

[tima01864]

Thanks for your knowledge Bryan and bearing with me!

[18Fiatsandcounting]

Sure thing, Tim, and we're both learning a lot of new things!

-Bryan

[Nanonevol]

I have decided to replace these calipers of mine with refurbished calipers from a trusted vendor, I will pay dearly for them but peace of mind is priceless.

Have you tried O'Reilly's Auto Parts for Fiat brake calipers? That's where I got mine and quite reasonably priced. Other auto part stores may also carry them.

[tima01864]

Nanonevol,

After all this trouble,once burned twice shy. Can I trust they will work? The e brake ecspecially. 90.00 bucks a caliper, they look good.

Tim

[DieselSpider]

Looks can be deceiving. I have received rear calipers reportedly from IA and some had the wrong number of Belville washers in them and others with the correct amount (5) did not have them stacked appropriately. |)()() is the correct stack and should offer about 150 lbs of springing however |)(()) or |(())) can give you a variable resistance starting at 150 to 300 lbs and going up the 300 to 450 lbs since pairing the Belvilles in the same direction multiplies the force required to compress them when you pull the brake lever.

It appears that even the parts manufacturers seem to have a problem with getting the rear brake calipers for our cars put together properly regardless of which store you buy them from.