andyz

Replaced a leaking caliper. No problem. Pedal was soft so bled all corners. no problem.

Do a test drive. Can only get the right front wheel to lock up. Doesn't feel like much braking from left front. Sucks. Pedal feel sucks.

Tighten up both rear drums. MUCH MUCH better. Locks up both front wheel almost simultanously under panic braking. Much better. Pedal feel pretty good.

Ok. Now. Day or two goes by pedal feel SUCKS.
Tighten drums to the point where they won't spin at all by themselves. Pedal feel good. Day or two goes by...you get the idea.

Replace the clevis and star wheel and little lever with parts from 'self adjust repair kit' $14 each side. Ugh. Grease it all up.

Still doesn't work automatically.

Rig up some S*** to hold the shoes in place with the drum off while I push the brake pedal with a 10 foot piece of PVC. Can clearly see that the stupid lever on the stupid NEW part is just like being pushed out away and totally not contacting the star wheel.

Work on this crap. GREASE EVERYTHING! Get in there with a paint brush with grease on it and grease all contact points. between the shoes and the backing plate. All this stuff is TOTALLY rusted and seized up. AMazing the shoes move at all.

LONG STORY SHORT

MUCH MUCH Better. Little lever now is moving into position and clicking over the star wheel nicely. Good.

NOW, Still does not really adjust it tight enough. Shoes are pretty worn down. Shoes are pretty uneven. Bottoms of shoes are way thick, tops way thin.

Can I ever get this to work? It seems to me as soon as the slightest bit of pressure from the thick part of the shoes is felt by the star wheel lever it stops ratcheting things up. But this is really not very tight because when you actually push the pedal during braking action there is a long way to before the whole shoes is really forced against the drum.

HELP

slowcivic2k

Thin uneven shoes require replacement, replace them and resurface/replace the drum.

Uneven shoes are a sign of maladjustment. clean all rust from the backing plate and apply a small amount of brake lubricant to the shoe contacts to ensure good shoe movement.

andyz

Brake Cleaned/Sanded lightly/brake cleaned/greased with hi-temp brake grease all backing plate contact points and lower pivot points.

Replaced shoes. And all springs.

STILL not happy with it. Replace the drum? Why If the drum is a little over diameter won't the self adjusters push the shoes out to meet it. I'm not really worried that it's gonna crack suddenly, it obviously not that worn down.

Adjusters definitely work now, but they only push the shoes to an initial contact with the drum. They don't appear to be strong enough to push just a few more clicks to get solid drag.

This sucks I still have to adjust these shoes periodically.

slowcivic2k

The drum has a maximum machine limit, if it is past this point, the drum requires replacement. If it is too large the wheel cylinder will push out too far and "blow out" onto your new rear brakes. Are those shoes the right size? Sorry, have to ask.

How does the parking brake feel? if the rear is to blame for the brake pedal the parking brake will suck too.

Comparing the rear shoes to each other, was one side worn down significantly more than the other? I'm starting to suspect a hydraulic issue, perhaps air in the system or a faulty cup seal in the master cylinder.

This is generic info for any front disc rear drum setup, what vehicle are we talking about here.

andyz

Drum is probably a little bit out-of-round. Has not been machined frequently. It doesn't look at all like it's worn too much. It is worn, but my instinct tells me there is no way the pistons are going to push out. Shoes are official specified from Advance.

When it's adjusted only by the self-adjusters, parking brake sucks. When I give it a few more clicks manually pedal feel and parking brake are nice.

Could be air somewhere, but I bled over and over and over to eliminate this potential. The wear pattern was somewhat disturbing. Wear was different on top of shoes versus bottom of shoe, also different front shoe and back shoes also different left side versus right side. I definitely account most of this to the seizing up on the lower pivot and general rustiness/lack of lube on the contact points.

Is it normal for one side to wear more? Isn't one side of the hydraulic system the primary circuit and the other the secondary? Over time won't this daisy-chain type of system cause slightly more wear on the primary circuit friction material?

93 Honda Civic LX 1.5 L


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How tight is right for the drums? When I click the wheel manually I get it so when I put the wheel back on you can spin it over and you can hear the friction and it will only spin 1 turn. Will this/any amount of dragging cause overheating drums/shoes/wheel bearing?

If your drums are perfectly round and the system is in absolute perfect condition you MAY be able to achieve a 0-drag but extremely close fit that would give good pedal feel. But for all practical purposes .... ... maybe a bit of drag is ok to get the pedal feel right?

slowcivic2k

Slight drag is acceptable for all drum brakes, 1-2 turns and it should stop on its own, if it "freewheels" you are too loose.

Are the adjusters on the right side of the car? They are directional, put them on the wrong side and they may back themselves off or at least not adjust at all.

Most modern cars use a dual-diagonal hydraulic system, where the LF and RR are one circuit, and the RF and LR are the other. They are driven simultaneously by the master cylinder which has two chambers that move at the same rate. If they moved at different rates (or more practically, one side has less pressure due to a leak or poor rear adjustment on one side of the rear brakes) the pedal will travel further, the vehicle may dart under braking to one side, or at the very least, the car may feel like its shifting under braking but goes straight.

andyz

I am definitely hitting it right when adjusting it manually.


They are definitely on the right side. If I take the drum off and back the adjusters up all the way, put the drum on and press the brake pedal like 50 times they are clicking clicking clicking all the way up until the shoes make contact.


I have to conclude the difference in wear between the two sides was due to one side being more rusted and poorly lubricated.


... ...

If I get it adjusted properly it only lasts a couple of days. After that I can freewheel again. Am I wearing the shoes down this quick? Will the star wheel back itself up due to vibration?

andyz

While I'm at it, any idea which color of springs in the hardware kit goes on which side?

gwhite0992

Can I ask how the problem was solved? Did you replace the large return spring?

jollyhonda

I am also wondering, it is an old post, but i am guessing you found it using the search button? I don't think the OP fully understood how auto adjusting drum brakes work. They are only supposed to adjust when applying the brakes in reverse. It has to do with how drum brakes work. You have a primary shoe that makes inital contact and inertia and it pushing cause the secondary shoe to engage. Backing up causes that to work backwards and that is what causes the adjuster to work. Sometimes you have someone that parks on the street, has a circle drive, etc, that may not have their car in reverse on a regular basis, and their brakes get out of adjustment. The long story short, if you are sitting stationary on blocks, the adjusters should not be doing anything. If they are, something is messed up. A great basic article....http://auto.howstuffworks.com/auto-parts/brakes/brake-types/drum-brake.htm.
so are you having a similar issue?

Rob

gwhite0992

My 2008 Honda Civic DX-G adjusts the shoes in the forward and reverse direction. I can manipulate (as if braking) the shoe adjacent to the adjustment lever with a screwdriver and watch the star wheel turn. I found the patent that closely matches my setup. If you Google US patent 4401195 you can see an excellent diagram and explanation of the operation. This design does not require a specific direction. An interesting issue was how they compensated for drum temperature. I see many guys writing about reversing and hitting the brakes so I guess there are different designs out there.

andyz

My final determination was that the backing plate upper slide was worn drastically out of proportion to the lower slide; due to the general design of the top-cylinder, lower blocking pivot; the mechanism has a tendency to simply seize the lower slide and wear the backing plate upper slide to the point where a proper star-wheel adjustment is impossible -- no matter how you work the star wheel over, the shoe is slipping tranversely because the upper and lower slide are uneven.
This wouldn't really be a problem, except the dual-circuit, proportioned design demands that considerable pressure be generated at the rear piston BEFORE can generate good circuit pressure at the front discs, which is really dangerous.

And this whole diagnostics would be helpful, except that the backing plate is NO LONGER IN PRODUCTION and ALL KNOWN STOCK has been expended.

andyz

Not on a honda.

andyz

Do you know if a Tesla S80 still has a hydraulic braking system? Has the federal government officially allowed a fully magnetic braking system?