Bee-Oh-Pee

Still can't get the Starfire's brakes right. I thought they were just too tight in the back, causing the left rear wheel (I'm pretty sure it's the left rear) to lock up prematurely -- which is constantly does.

I had done a lot of back-up braking a week or so ago just to see if the self-adjusters would kick in and straighten things out. But it didn't make an iota of difference.

So I pulled all 4 drums yesterday, adjusted them all the same so the shoes barely touch the drums at rest -- fronts had actually been too tight.

Now it's still pulling significantly to the right when I hit 'em, and that L.R. wheel still locks up prematurely.

My guess is that either the LF wheel cylinder is kaput, or maybe there's some problem or obstruction with the proportioning valve -- although I think that's a pretty simple gizmo with little else than plumbing. (All lines appears fine -- no leaks, bends, kinks, etc.)

Generally, the master cylinder and hydraulic pressure seem great; no sponginess or "give" at pedal at all. All shoes were new when I got the car, and still look 99%, since I hardly drive it.

Wheel cylinders appear either new or rebuilt.

I guess I just need to keep plugging. Was wondering if somebody with more experience than I have with these brakes has any ideas before I get too much deeper. Appreciated!

joe_padavano

There is NO proportioning valve on drum brake cars. In fact, there is no valve at all on your car since you have single circuit brakes. You may have a bad rubber line that restricts fluid flow one way or the other, however both rear wheels feed from a common rubber line to the rear axle. This is almost certainly a problem at one (or both) of the wheels. Have you pulled the drums to look for seepage? Contaminated linings will lock up. Out of round drums will also cause problems. Check each side carefully for out of round or bent parts. Look for grooves in the backing plates where the edges of the shoes ride. I've had problems due to this. A grinder will smooth them out.

Bee-Oh-Pee

Yes, Joe... that's what I figured; "plumbing only": just T's and junctions. Before I break the hydraulic seal, I wanted to see if I could get any ideas to avert a system bleed; but I suspect pulling one or two cylinders will be next.

No seepage anywhere; rubber lines do NOT look original, and my first thought is that they're fine (although that's no guarantee they are).

I'm guessing the lockup and the (severe) pulling are related; and behavior is VERY consistent.

There's no contamination inside the drums or on the shoes. Drums are original, but I'm thinking out-of-round would cause at least minor pulsating, and would not be the primary cause of these behaviors -- but then again, that's why I'm asking. I'd be inclined to pull one or two cylinders before turning the drums. But having them turned or at least checked may be on the list.

I have checked each side carefully for bent (and even missing) parts; but I have not looked for grooves in the backing plates. I will check for this when I get out there. Sounds logical, and is something I was not aware of....

Thanks for the help....

lemoldsnut

Years ago they taught us that if the brakes were turned over a certain amount different, so if one drum was cut larger than the other on the same axle line by a certain amount it could cause a pull. I don't remember what that difference was. They could be within tolerance but too much different. Did not deal with that issue much but do remember it being brought up. We used to use a tool we called a safe set gauge to make sure each drum to shoe setting was correct also. Tires and tire pressure can cause pull also.

Just some thoughts

Hope it works out

Larry

Bee-Oh-Pee

Thanks, Larry. I will certainly look more closely into those things. Air pressure is fine, and no pull at all until the brakes are applied. It's possible one drum was turned and the other not; or one more than the other. But both star wheels are almost exactly in the same position on the threads. The car has very low miles, so I'm thinking I'm going to find a problem with a cylinder. But I'm all ears.... Thanks again....

Don R.

How long ago were the brakes rebuilt, and did the car sit for a long period after without being driven? You could have some "frozen" wheel cylinders. If you are considering opening them up anyway you can try moving the pistons back and forth in the cylinder to see if they are free, unfortunately you will have to remove the shoes to do it. If any of them feel locked there is probably rust inside and they should all be replaced.

Bee-Oh-Pee

I think that's what I'm going to have to do next, Don. The brakes were re-done in '10 or maybe '09. It's possible some rust or scale formed in there; but my suspicion is that the brake job was done by a half-arsed mechanic, and a cylinder was not put together properly in some fashion. We shall see! Probably won't get to it before next week.

Thanks, guys.

droldsmorland

Make sure the primary and secondary shoes are in their proper respective positions. The shorter shoe, the primary shoe, goes towards the front on all 4 wheels. Grab the shoe assemblies and see if they are free to shift back n forth. I find that if they are dirty rusty etc they wont preform as intended. If this is the case disassemble clean and grease accordingly. There is 3-4 shoe to backing plate interfaces that need a dab of brake grease. Anti seize on the star wheels and replace the hardware with a new kit. Whenever I do a drum brake job I usually automatically replace the hardware unless its in unusually good serviceable shape...which is rare.
Are you well versed on how to properly adjust drum brakes?

Bee-Oh-Pee

Dr. Morland: to answer your question at the outset, short answer is "no." I used to adjust them frequently thru the peek-hole by spinning the wheel until the shoes would contact, then back 'em off a click or two. (This was much easier for me back in my heyday, as the Chryslers I used to play with had two holes.) The holes were never punched out on mine, and I don't have any plugs just yet; so I adjusted them with the drums off so that the shoes were as "out" as far as possible and I could still put the drums back with no difficulty.

That statement about the different primary & secondary shoes is a definite point I will look at (before I remove the shoes and pull a cylinder). I assume it's possible to easily interchange them and still have all the hardware align to the backing plate? And I'll hit the contact areas with the dab of grease as you recommend.

The appearance of ALL the hardware is very good to excellent. Some slight discoloration -- but no rust or scale. Just a little dirt and brake dust.

Thanks....

droldsmorland

Yes you should punch out the adjuster holes. Keep in mind the shoes need to be initially adjusted then after a short break in period readjusted as the first layer of material is somewhat sacrificial. The self adjusting feature is supposed to do this for you. But it doesn't hurt to monitor it.
With everything clean and lubed grab the shoes and move them side to side to simulate the automatic adjusting feature. Verify that the adjuster is contacting the star wheel and actually moving it one click at a time. If not the star wheel, the adjuster piece or the rod thats attached to it is worn. Replace accordingly.
As for adjustment; I like to bring the shoes up to the drums and with the tires torqued onto the lugs at ambient temperatures I like to see about one and a half full revolutions on the tire before the drag stops the tire. Take it for a road test and readjust. Then after your where you want to be with the adjustment do the back up thing while braking. The reverse adjustment procedure should only take 10 feet or so or 2-3-4 pedal actuation's to self-adjust. Now take it for a road test and try to lock them up and see if it stops evenly. If it does not then look at what Joe and lemoldsnut suggested. Could be a bad hose or wheel cylinder or a drum tolerance problem.

CutlassDad

Is there a chance that one of the steel lines might be kinked or flattened?That kink, if present, would restrict the flow of brake fluid, and cause that brake to apply later, causing the pull. The opposite brake could still fully apply and lock.

Don R.

John, you said you did the backup and stop routine to activate the self adjusters but did not notice any change, did that include no change to pedal firmness? If so another possibility is that the adjusters are frozen or they were mixed up and put back in the wrong position. They are either right or left hand thread depending on which side they go on. If they are misplaced they would actually loosen the adjustment rather than tightening. A long shot but worth a look.

Bee-Oh-Pee

Don, Dad, & Dr.:

Thanks for all the great advice... I have this thread printed out and as soon as I can (may be Friday), I'm going to go over the system in accordance with these suggestions. I'm guessing this info will be enough to get 'er "straight" so to speak; but I'll keep the board updated of my success.

Thanks again & I'll be back....

Bee-Oh-Pee

I believe I have a little more work cut out for me than if I'd have lucked out and seen something obviously wrong, such as interchanged shoes. Another thing is that the hardware isn't really as pristine as I thought when I first pulled off the drums. The only thing I see is a couple of return springs that are hooked "over" when they are pictured as hooked "under" (or vice versa) in the manual; not sure if that could be causing (or be related to?) any of the symptoms I'm experiencing or not -- although normally I try to hook up everything exactly as pictured.

Some hardware appears green and some red.

I'll probably order 4 new hardware kits as advised and replace everything, along with a thorough clean and lube. I'll take the cylinders apart and see what's going on with them before buying any new ones.

Here are the pic's of the wheels, in this order: Driver's front, Driver's rear, Pass. rear, Pass. front.

If anybody sees anything awry, maybe he could let me know. I probably won't be pulling it apart until tomorrow. Thanks!

Greg Rogers

I had a 65 Dodge Coronet (I Know- not a Olds but still a old 4 wheel drum car). I pulled my hair out with a pulling problem for a couple years. I looked at everything as you have -still pulled. I finally sold the car to a freind- he put new tires on it and had front end aligned- no more pull!! The tires looked good but apparently had some problem.

droldsmorland

Your hardware looks fine,

Bee-Oh-Pee

Thanks, Dr. Olds & Greg. Looks like the wheel cylinders will be coming apart next....