Emergency Hand Brake repair

Ten years ago when I was 30 years younger, had 2 eyes and a nimble body, I took apart the rear calipers and made the e-brake work so much better. Well it needs it again. I can't remember what to remove first to gain access into the inner sanctum of the e-brake chamber. Which as I recall was gunked up bad. Now the lever (yellow) cannot be moved at all. Will a brake guru help me please. What do I remove first and what daren't I touch. 1980 gtbi

Yes I have the Rainbolt document but it glosses over the part about removing the brake caliper in para 9.
Image Unavailable, Please Login

 

Left side lever totally frozen. Cable came off easily. Pads like new. Got adventurous removed 4 bolts releasing the outer caliper. 2oz brake fluid came out too, be ready. Tools: 11mm socket + T-27 Torx. (I'll document the process for the next guy).

Tks tatcat re cap#23. Right side probably just needs adjust but with left frozen, it needs to come off and get some love.

Doh...re birdman's stuff...we just exchanged links...shows how much attention I'm paying...his brake page is probably all I need.

 

Last question - right side e-brake lever isn't frozen in place on the caliper...left is. TRutlands rebuild kit with 6 'O' rings and a freeze plug is now $70. I'll call tomorrow. BUT

Should I rebuild both sides or just the bad side? Mama said not to fix what wasn't broken. Papa said better do it all while you're in there.

 

Outboard caliper adjust has no circlip on mine...just a lock nut at the 4mm hex adjust threads. There is an 'o' ring there also.

Well I ordered 2 rebuild kits from TRutlands for $60 each plus $8 s/h came to $200. WAAAT? gotta callem tomorrow on that.

Mine has a circlip on hand-brake lever bottom which took me most of an hour to remove.
Also at inboard caliper is another circlip which holds the adjustment screw in place that took another hour.
Seems you have to hold your tongue just right and make this funny noise...it comes right out then.

Lesson learned, don't disassemble while sitting in a haystack. Finding the 'pill' which flew out was a matter of luck.

 

Rick, This pic is located on the Birdman site where I'm finding the best info. Hope that helps.
Image Unavailable, Please Login

 

Mine doesn't have that clip. The nut is a locknut and only needs to be backed off slightly to make the adjustment.
At one point I thought I had a spare clip but it was for the top of the e-brake lever rod holding the spring in place.
Of course another at the rod under the freeze plug. Third holding the inner caliper sombrero hat/spring in place.
So, I had 3 clips...did you have 4?

Incidently two tips...to slip the tiny 'O' ring over the threads on the outer adjustment
screw I used a 1" piece of electrical shrink tube to protect it from damage on the threads.

Other tip on inserting the circlip holding the sombraro hat/spring was to use my drill press holding a socket and
extension down and stable while I worked on the clip. Also, I ground the tip of a small screwdriver fashioning
a tool to fit into the circlip hole for me to pry. The drill press light was handy, the whole setup allowed my
plenty of room and visibility to work on the clip.

 

Just crawled out from making that adjustment. The adjustment screw isn't loose once that lock nut is tightened. That outer adjustment screw is fixed in place by the nut on the outside and the adjustment screw flange on the inside. The screw never moves but provides a minimum stop for the piston. Hydraulic pressure will push the piston inward against the rotor and when pressure is released, the piston will back off a few thousandths but never back any farther than against the static adjustment screw.

I must say the adjustment is touchy. I don't have a 4thousandths feeler gauge, my thinnest is 0.008". There is about 10 degrees difference between tight against rotor and back allowing the 8thou feeler in. Actually come to think...it's calcuable. If the adjustment screw thread is 10 turns per inch (wag), that's 3600 degrees per inch, that's 0.0003" per degree, that's 3 thousands for 10 degrees, that's close to what I thot. Jeez, science at work.

What gets me about the 308 hand/e-brake is the fact it doesn't pinch the rotor like the all normal brakes, it puts pressure in the inside face of the rotor causing friction, yes, but big time force against the axle bearing. I've worked on other such one sided e-brake but the main caliper floated causing a true pinch even though pressure was applied to one side. Gotta fault Ferrari design on this one. (Luca, I'm available)

 

On the inner caliper, the adjustment screw floats. On the outer end is the e-brake rod, then the 'pill', then the piston. The spring/sombrero hat gizmo is what is held firmly in place by the circlip. The spring/sombrero hat gizmo only provides a guide for the adjustment screw. That adjustment screw needs freedom to move in/out as the e-brake rod is allowed to provide pressure on it.

Re being flat...the least tiniest slightest incline at a stop and my car will roll backward at least a foot before I can get my foot off the brake and onto the accelerator to get the car moving forward again without it stalling. And invariably some joker will pull up tight against my rear bumper. Yes I need the e-brake + we have hills.

 

Although mine didn't have that circlip on the outside, I can understand having one there in case one were to loosten and loose the nut, the brake would still stay intact and work. But I have no worries about mine being missing (on both sides).

 

It's easy to shrug off $800 for a pair of rebuilts but with the 'O' ring set $160+ per side and his $200 off for sending in the cores, that makes it $600-$320=$280 as the cost for his efforts for both sides guaranteed. Reasonable in my book having just gone through rebuilding one side. My rebuild effected me nothing I might add as my hand brake still doesn't hold the car now that both sides of the hand brake are working.

Think I'll check into Brembo for kicks.

 

I've adjusted them by the numbers. But the design is poor and I'm starting to wonder if they depend on a particular type of pad material. When I bought the car a dozen years back the e-brake didn't work. Five years ago when I had new pads installed by Ferrari mechanic, the e-brake still didn't work. Now, when I noticed the left e-brake caliper lever was frozen open, I thought I could remedy the situation. But the design is faulty. Imagine pushing a pad against a moving rotor vs pinching the rotor with vice-grips. Rotor and pads are smooth and no amount of push force can equal the pinch because the axle will bend and bearing will give way first.

Materials have both static and dynamic friction. I'm thinking the pad material available when the car was new had better static friction than those available now. Undoubtedly newer pad material has better stopping distance but the static friction has suffered.