66 e brake adjustment

[Randy S.]

My emergency brake pulls all the way out before I get any emergency brake engagement. So I went under the car to take some slack out of the cables at the adjustment point and noticed the nut was all the way forward on the threaded rod. No more adjustment available!

Is there another point of adjustment available? It looks like the cable housing from the handle clamps to the frame. Can this be moved back?

[Joe L.]

Re: 66 e brake adjustment

Randy-----

The emergency brake is adjusted in 2 locations-----at the rear disc parking brake shoes and at the equalizer. The shoe adjustment must be done first and then the equalizer adjustment. I strongly suggest following the overall adjustment procedure found in your factory service manual.

If the parking brake shoe adjustment does not restore a proper range of adjustment at the equalizer, then you may have an improper length rear cable installed.

[Ed Jennings]

Re: 66 e brake adjustment

In addition to Joe's comments, if the adjustment at the shoes does not restore proper operation the shoes may be badly worn or the mechanism may be inoperative. If your rear calipers have never been removed, you may find a pile of rust in place of the parking brake mechanism. Replacement parts are readily available in stainless steel if they prove necessary.

[Gary S.]

Re: 66 e brake adjustment

In addition to what Joe and Ed said, if the cable is stretched you may have too much play in it to properly adjust it. If you find all of the hardware is good then you 66 GM Chassis Service Manual has a very nice description of the E brake adjustment procedure. IIRC, something like adjust the E brake shoes until they just touch the rotors, then back off a notch or two, then you adjust the cable tension so that it takes a certain notches on the E brake handle. The book was very clear on it (meaning - don't take my so-so description on this). Since my 72 has a console mounted handle the procedure is slightly different but still described clearly.

Gary

[Harmon C.]

Re: 66 e brake adjustment

Some of the replacement E-brake shoes are undersize and I think it is the ss ones. It has been mentioned on this board before. Lyle

[Ed Jennings]

Re: 66 e brake adjustment

No real reason to use s/s shoes. However, the s/s hardware is pretty nice. On hobby cars that don't see much bad weather, it probably doesn't make much difference. I'm not sure the hardware is even offered in carbon steel at this time, however.

[Todd H 26112]

...same here but I'm not impressed by my ebrake

Joe et al

I put all new shoes springs on some time ago and followed the adjustment steps as outlined in the CSM. That was quite a few years back so forgive my faulty memory as to the details but I too remember counting clicks and such. They kinda sorta work - but to be honest - not that well. My various other more modern cars perform much better. Crank htose up and the cars sit like glue on even the steepest of hills. But on my early C3 - when I crank the handle way up - it is only marginal - like working OK just on mild slopes. I've wondered if something like teh cable or linkage may be at fault, stretched, aged and contribue to this? The mention of 'undersized' shoes is interesting as well - I did use SS components.

Also - just how good should I expect the C3 parking or e brake to be compared to say a modern car? The reason I ask is that I have heard it characterized as a so so brake setup in the past.

thanks

[Joe L.]

Re: ...same here but I'm not impressed by my ebrak

Todd-----

The 65-82 parking/emergency brake will be, when it is at its VERY BEST state of adjustment and repair, VERY MARGINAL in terms of performance. For whatever reason, they just never got this right. Plus, they never did a lot to improve things over the many years of its use, even though the marginal performance of the parking/emergency brake was rather notorious. In 1967, they switched from the under-dash actuator lever to the center console lever. That was an improvement. But, that's the last improvement that they made to the system which "soldiered on" for 15 more model years essentially as-is.

[Todd H 26112]

Thanks - marginal sounds 'bout right

I appreciate your candor.

I do now recall that I purchased std metal shoes and SS hardware like the springs and such.

thanks,

[Gary S.]

Re: ...same here but I'm not impressed by my ebrak

You think the GM engineers didn't get it right? My daily driver is a 1979 Mercedes 240D. It has a rear brake setup that looks and works suspiciously like the 65-82 Corvette E brake. Same inner E brake setup and it really only holds well in reverse. German engineering? Now, if you want to talk longevity with regard to their diesel design, that is another question.
Gary

[Harmon C.]

Re: 66 e brake adjustment

Ed to pass a PV I adjust the E- brake shoes to just short of smoking and then tighten the cable soon they are back to not holding very good. I use SS hardware but not shoes as I see no need also. Lyle

[Joe C.]

Re: 66 e brake adjustment

Randy:

Case in point:

The ebrake on my '65 holds like glue. If I apply it, then try to move the car, it'll stall the engine, every time. There is no drag on the shoes when disengaged. It holds tight, even on steep grades.
The hardware is SS, the shoes are standard type, the front and rear cables, handle assembly, and pulley are all refurbished original parts. The only mod that I did, was to remove a frayed end of the left end of the rear cable. Reinstalled the ball end and re swedged.

Joe

[Randy S.]

Re: 66 e brake adjustment

Thanks to all for your input

Since I get some brake engagement when the brake handle is out about 5"-6" I was assuming I could engagement earlier with the equalizer adjustment. I am not optimistic adjusting the star wheel at the brake shoes will help. If you look at UPC 5 C1 it seems to me the location of the front cable assembly is also relevant. If the cable housing is too close to the lever assembly, the lever can never be pulled enough to take the slack ot of the equalizer cables.

I'll pull the calipers to inspect the brake shoes. Good tip about the undersized shoes with the SS versions

Randy

[Todd H 26112]

Re: ...same here but I'm not impressed by my ebrak

I don't know who copied who - but on occasion I've seen other 'baby' drums inside of rear disc brake rotors but I don't recall where. I don't see it any more and I sure don't miss it!

On the other hand, my old get around Toyota truck has the same pull out handle just like most C2s. If I leave it on and try to move - it hardly budges. You'd just about fry a clutch before that thing is going to let you move. Lots of miles and no service too.

Back to the C2/3 brake - I wonder if thoroughly seating them might help a little? What if you drove around and cranked on the handle or left it up - then came back and re-adjusted everythign from scratch. I almost vaguely remember trying something like that - but now I don't remember.

[John H.]

Re: ...same here but I'm not impressed by my ebrak

While it's all apart, having the shoes "arced" to match the I.D. of the drum section of the rotor provides more effective surface contact, but even with that, the system is still very marginal and is a far cry from the effectiveness of today's parking brake systems. MVSS regulations these days require a "ramp test" to certify parking brake system effectiveness; no such regulation was in force during the C2/C3 years. Just the nature of the beast.