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General Tech Rear Brakes TR4-4A--Adjustment

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KVH

KVH

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I'm experiencing an odd issue. At least it seems. No matter how I adjust the emergency brake, the car slips slowly on slopes. The emergency brake simply won't hold. So, I took out the clevis pins and adjusted the emergency/hand brake cable. I followed the manual as best I could, but I have only a slight improvement. But I'm noticing another problem--when adjust the brake shoe clearance, it gets to an "all or nothing" situation. If I tighten either side the wheels spin freely, then begin to slightly bind, but just one more click and they're locked tight and the wheels stop dead. In other words, l'm feeling resistance only slightly, then it's a complete stop.

Is this a brake bleeding issue. Air in the brakes? I think not. On that thought, my brakes seem OK, but a bit soft. But the car slows and stops fine.

Any ideas welcome.
 
you have done right by removing the hand brake lincages.
buff the shsoes and drums with some rough paper,
adjust so they are just rubbing, tap the drum with a hammer and re check adjustment,
re fit hand brake lincafes and adjust hand brake travel,
give it a run and holding the hand brake release button in pump the hand brake to bed the shoes in,
you should be able to lock the brake up.
while the drums are off check for any contamination on the shoes, make sure they are fitted the correct way around, they have a leading and trailing edge. make sure the handbrake lincage is free and allowing the shoes to fully retract the cylinder before adjustment.
 
The adjustment seem normal to me...slight resistance then one more quarter turn and the shoes lock..I don't know if I have an 'inbetween' either; but you could try cleaning the adjuster with brake cleaner.
As far as the 'ebarke' it'll hold better if you push down hard on the brake pedal then set the hand brake before letting up the brake pedal.
 
Your shoe adjustment sounds normal. I would leave it at the light drag, unless mpg is more important to you, then set it at the first notch with no drag.

How much distance are you getting at the handbrake handle?
 
These cars, especially the TR4A, were notorious for having ineffective hand brakes. Almost all cars in the 1960s were just as bad. This became a safety issue, and that is largely why today's cars are much better in that regard.

I don't know if anyone has come up with a clever modification for the hand brake, but I would be interested in hearing about any that exists.

Your rear brake adjustment sounds normal, to me.
 
Thx guys. My hand brake clicks up about four clicks. I always add a rock or block behind a tire if I’m on a slope. Darn, I did forget to buff up those brake pads when I hard the wheels off. You know, my cars are one of my best exercises. I may also see if tapping the brake drum back plate helps. Thx again.
 
4 clicks is good. Definitely on the tight side, if anything.

My TR2 handbrake will lock the rear wheels on pavement at 40+mph...which is amazing, since I have had issues with the Lockheed axle leaking gear oil all over the shoes! I cleaned the shoes with carb cleaner every time it happened, and learned to leave the level of oil in the axle on the low side.

Anyway...back to your brakes. I would go through the manual to ensure all the cable lengths are to spec. There are 4 levers in the system, and when properly adjusted, the levers have the most mechanical advantage by placing the levers at 90 degrees to the cables when you actuate the brakes. Every cable at the wrong length will change the lever geometry and reduce your total leverage on the brake shoes.

Once you are sure the cables are correct, then I would oil and grease everything, Make sure the sheathed cable has grease exiting both ends when lubed. Ensure the slave cylinders can slide back and forth without undue force. If none of that helps, it may be time to change the shoes and scuff the drums. Shoes can become hardened over time, especially if oil or grease has gotten to them and gotten baked in. Likewise, the drums can become glazed on the surface, both of which reduces the drag of the shoe against the drum.

Before changing shoes, you could always try the carb cleaner, LOL. When I first cleaned my shoes, it was intended to be a stop-gap while new shoes arrived. Here I am, 7 years later and the original shoes are still going great...with the box of new sitting on the shelf!
 
My understanding, since I have zero direct experience with TR2s and 3s, is that they were better. Also TR4s. It got bad when the hand brake was moved to the top of the drive-shaft tunnel in the TR4A. It just doesn't have enough leverage.
 
I might try new shoes. Mine do look a bit glazed even though I cleaned them. I should’ve scuffed them, too. I notice my handbrake holds better on uphill than downhill. Either way, however, I have to really give it a yank.
 
Hi and Merry Christmas,

I was looking at another forum about the parking brake adjustment. In this case, the rear wheel cylinder bell crank pivot had worn a groove in the backing plate. It would shift in the groove when the hand brake was applied. The fix was to weld up the groove and grind flat.

Along the same lines, it looks like my backing plate has grooves worn in by the brake shoes. I cant tell if it wear or it was machined that way. Has anyone tried to file them out?

Thanks, Roy
 
Funny how wear can be so precise that it looks machined! It is wear, though, as the shoes should be against a flat spot so it can drift with drum and lining wear.
 
I'm a little late to the game but...

You might try handbrake extensions, they increase the leverage of your handbrake.
Handbrake extensions
Also, be sure to step on the brakes firmly when setting the handbrake for parking. It will allow some additional leverage.

Rod
 
I’ve taken the advice. Thanks all. Handbrake works better now. Especially after replacing my brake lines with stainless steel braided ones. Huge improvement. I must have had leaks. My fluid reservoir said as much. Those old rubber lines are just so bad.
 
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