Parking brake ineffective with adjustment screw full tight -97 SL1

[steve seibel]

I've screwed the adjustment screw all the way in and the parking brake is just barely engaging, won't hold the car on any slope at all.

What might be wrong?

If my recollection is right, the problem *may* have begun after replacing the master cylinder on a rear brake drum.

Thanks for any pointers--

Are there any other adjustment points for this system?

( 97 Saturn SL1 )

[fetchitfido]

There's also a cable slack adjuster for the cable right off the pull handle. IIRC it's a 10mm nut and accessible without taking the console out.

[steve seibel]

Originally Posted by fetchitfido

There's also a cable slack adjuster for the cable right off the pull handle. IIRC it's a 10mm nut and accessible without taking the console out.

Thanks-- but that's actually the screw I adjusted. Is there any other adjustment?

PS the handle actually seems to move about the right amount with that nut *full down*-- starts getting tight about 5 clicks up, really hard to pull beyond 7th click and can't pull beyond 8th click-- but with rear wheels jacked up, still am able to turn rear wheels by hand in that position, just a little dragging-- and that's with the nut *full down* (I think-- can't turn any more, and can count 28 threads showing above top of nut)

[billr]

Pull off the drums and visually inspect inspect the motion of the levers and shoes as somebody actuates the hand-lever.

[steve seibel]

Originally Posted by steve seibel

Thanks-- but that's actually the screw I adjusted. Is there any other adjustment?

PS the handle actually seems to move about the right amount with that nut *full down*-- starts getting tight about 5 clicks up, really hard to pull beyond 7th click and can't pull beyond 8th click-- but with rear wheels jacked up, still am able to turn rear wheels by hand in that position, just a little dragging-- and that's with the nut *full down* (I think-- can't turn any more, and can count 28 threads showing above top of nut)

PPS I just notice that the Haynes manual said with wheels off the ground, you should already feel a light drag on the wheels at the *first* click of the brake handle-- *that"* was definitely not happening. It's only a moderate drag on the wheel I pull really hard on the brake handle to get it up to 7 or 8 clicks. I can't pull it higher than 8 clicks.

But Haynes manual said a "moderate pull" ought to get the handle to 4 to 7 clicks and that part seems to happening-- I'd describe it as a "moderate pull" needed to get it up to 5 clicks, and a really hard pull to get to 7 clicks, and I can't pull it past 8 clicks. What is keeping the handle from rising up higher? -- clearly the tension in the cable, right? So then why is the parking brake not effective?

Because as a test I backed the adjustment nut *all the way out* and then I can pull the handle up to the 4th click before the adjustment nut even gets snugged down against the fitting by the cable tension, and it's easy to pull the handle all the way up to the hard stop at 19 clicks, without putting *any* noticeable drag on the wheels. That's *not* the handle behavior I'm seeing with the adjustment nut *all the way down*.

Based on all this it seems like it *ought* to be effective at least when adjusted with the nut *all the way down*, but it's not-- ??

[billr]

What is the big mystery? You can see the (threaded) ends of the cables moving up in the cabin when you pull up the handle, correct? Now, you simply need to peek at the other end of the cables, down behind the drums, to see what isn't moving.

[steve seibel]

Originally Posted by billr

What is the big mystery? You can see the (threaded) ends of the cables moving up in the cabin when you pull up the handle, correct? Now, you simply need to peek at the other end of the cables, down behind the drums, to see what isn't moving.

The wheel is back together right now, but the brakes definitely were moving when I pulled on the emergency brake cable.

[steve seibel]

Before I take anything apart again I want to clarify--

I've been reading about how to make the brakes self-adjust--

See for example this post-- http://www.saturnfans.com/forums/sho...92&postcount=2

My question is, what is the exact role of the parking brake in this procedure? When should I pull on the parking brake handle, after each time I stop the car (in reverse) with the brake pedal? If I don't pull on the parking brake handle do the brakes still self-adjust? And should I do some stops going forward too? Or is it only going backwards that makes things adjust?

(The other day I tried to stopping the car with *only the parking brake*, while going in reverse-- I did that a *whole much of times* and, besides the fact that the car barely decelerated at all while rolling backwards in neutral with the parking brake pulled -- there was no apparent effect on the brake adjustment.)

But apparently I am supposed to stop the car (in reverse, or both ways?) with the brake *pedal* and *then* pull on the parking brake handle, after each stop, is that right?

Exact sentence from Haynes manual-- p 9-13-- "Make a number of forward and reverse stops and operate the parking brake handle to adjust the brakes until satisfactory pedal action is obtained."

I understand that if the brakes are too far out of adjustment I many need to open the wheel back up and move the adjuster manually, but I just want to understand the most effective way to activate the adjuster automatically before I decide to do that--

Thanks--

[trottida]

Look at videos outlining how to replace the rear brake shoes. Towards the end of the procedure it shows you how to adjust the rear brakes to a point where there is a little drag when rotating the wheel.

That star wheel adjuster is supposed to be self adjusting as the shoes wear down but it doesn't work well. The "auto" adjustment happens when you reverse and brake with the brake pedal. As a result the parking brake will get sloppy/ineffective as the rear brake shoes wear.

As you've discovered you can use the adjuster under the console to compensate however it is better to readjust at the brake shoe - reset the drag. This is especially apparent when you reach the limit of the adjuster as you have. Back off that adjuster under the console to give some slack and then adjust the brake shoes to restore function.

[steve seibel]

Originally Posted by trottida

Look at videos outlining how to replace the rear brake shoes. Towards the end of the procedure it shows you how to adjust the rear brakes to a point where there is a little drag when rotating the wheel.

That star wheel adjuster is supposed to be self adjusting as the shoes wear down but it doesn't work well. The "auto" adjustment happens when you reverse and brake with the brake pedal. As a result the parking brake will get sloppy/ineffective as the rear brake shoes wear.

As you've discovered you can use the adjuster under the console to compensate however it is better to readjust at the brake shoe - reset the drag. This is especially apparent when you reach the limit of the adjuster as you have. Back off that adjuster under the console to give some slack and then adjust the brake shoes to restore function.

Thanks, that helps -- it doesn't seem practical to feel the drag on the wheel (/ hub) unless the wheel is mounted. In which case I guess I'm repeatedly taking the wheel on and off during the adjustment process. Or do you find that you can sense when it is starting to drag just by turning the hub itself?

On this car, there's no way to reach the adjuster with the hub on, let alone with the wheel on, right?

[fetchitfido]

I never had any luck with the auto adjuster working. The access hole for the adjuster is on the wrong side of the backing plate, you might be able to reach the adjuster but it'll be harder than normal.

You'll want the drum to be a tight fit on the shoes, if the drum has a lip worn into it you won't be able to get it right unless you grind it off or get new drums.

[steve seibel]

I backed up, stopped with the brake pedal, pulled and released the parking brake handle, drove forward, stopped with the brake pedal, repeated the whole process, dozens of times with no luck. So I guess it's time to take off the wheel and turn the adjuster manually some more.

Another thing I'd like to better understand is this-- if the brake on *one* side is way out adjustment, would that somehow prevent the parking brake from engaging the brake on the *other* side? Given that I've adjusted the adjustment at the parking brake handle so that the handle *does* come to a stop after 7 or 8 clicks, i.e. the cable tension *is* limiting the total possible travel of the parking brake handle.

I don't know how the single cable from the parking brake splits into the two cables to each wheel. Is it a simple Y or T-shaped cable, or is there some sort of swivelling bracket that distributes the load evenly? I'd love to see a page from the actual shop manual that shows this in more detail, to understand if one side being way out of adjustment could somehow affect the other side.

The reason why I ask, is everything seemed to be working fine before we replaced the brake cylinder on the right side, so I don't know why the left side would have suddenly gone out of adjustment.

[steve seibel]

Also -- re http://www.saturnfans.com/forums/sho...2&postcount=2p -- is it really that helpful to do the maneuver that violently? What is going on the mechanism that couldn't be achieved with a little less speed and abruptness of braking?

[trottida]

There are 2 cables running into the interior of the car that attach to a bracket on the single cable that goes to the parking brake handle. You'll see in parts books there is a front cable and rear cable (x2). The attachment point for the 2 rear cables to the front cable is under the console towards the rear. You can see it at the left of this photo borrowed from another post. A gold coloured object just after the pbrake handle.

Dragging the brake by rotating the hub is how I do it. Just put the drum back on and give it a spin. I try to get them somewhat even from side to side. Don't forget to back off the adjuster at the parking brake.

As mentioned there is an adjustment port for adjusting the star wheel however it is on the wrong side. There is a special Saturn tool (pn SA9201B) to work the adjuster with the drum on but it's not worth sourcing one. I have included a sketch of the tool and a diagram showing how it is used below.

Wolfman is a reputable source in that linked post. At that time he was a Saturn technician at a Saturn dealership and is very knowledgeable in the S Series.

[billr]

If the self-adjust system is working properly, none of that hocus-pocus is needed, the brakes will adjust fine in just a short amount of normal driving. If the self adjust is not working properly, then none of that hocus-pocus may be useful.

Trying to "force" adjustment like that is only justified when you do brake work and did not do initial adjustment of the star-wheel. For instance, I can certainly understand a shop leaving the brakes "loose" to save time and ease assembly; then forcing quick adjustment so the car goes out their door with the brakes fully adjusted.

I'm not sure, but my perception is that the hand lever has ample travel to compensate for any reasonable mis-adjustment of the star-wheels. It is time to look inside the drums for further clues.

You mentioned recent replacement of one wheel cylinder. Was the other brake fussed with at the same time? Did you take off only the cylinder (and drum), or did you disturb any of the springs/levers while changing the cylinder?

[steve seibel]

Originally Posted by steve seibel

Before I take anything apart again I want to clarify--

I've been reading about how to make the brakes self-adjust--

See for example this post-- http://www.saturnfans.com/forums/sho...92&postcount=2

My question is, what is the exact role of the parking brake in this procedure? When should I pull on the parking brake handle, after each time I stop the car (in reverse) with the brake pedal? If I don't pull on the parking brake handle do the brakes still self-adjust?

See, the thing is, looking at the mechanism, it's obvious that only *pulling on the parking brake handle* moves the little prawl that engages the star wheel. I can see the prawl move when I pull on the parking brake handle. So that *has* to be a part of engaging the self-adjustment mechanism. But apparently driving in reverse and stepping hard on the brake pedal is important too?

In my particular case, I'm not certain that the prawl is consistently engaging the star wheel when it moves. Something may be mis-aligned. Still looking--

[steve seibel]

Originally Posted by trottida

There are 2 cables running into the interior of the car that attach to a bracket on the single cable that goes to the parking brake handle. ... . You can see it at the left of this photo borrowed from another post. A gold coloured object just after the pbrake handle.

...

As mentioned there is an adjustment port for adjusting the star wheel however it is on the wrong side. There is a special Saturn tool (pn SA9201B) to work the adjuster with the drum on but it's not worth sourcing one. I have included a sketch of the tool and a diagram showing how it is used below.

...

Much appreciate the photos and other images, especially of how the two cables join into the one.

However I don't see any holes where I could poke that tool in, either on the drum or on the backplate. (Edit: I see your drawing specifically shows a hole in the *backing plate* -- no such hole in my backing plate.) My car is a 1997 SL1. Would the hole/s be on a later model perhaps?

[trottida]

There should be a plug in the backing plate that looks like one of the 2 options below. This is from a 97 parts listing however it is applicable to 1991 through 2002 S Series. I couldn't find a good picture of the backing plate itself to identify the access hole. The backing plate are part numbers 21013315 and 21013316.

[steve seibel]

Originally Posted by trottida

There should be a plug in the backing plate that looks like one of the 2 options below. This is from a 97 parts listing however it is applicable to 1991 through 2002 S Series. I couldn't find a good picture of the backing plate itself to identify the access hole. The backing plate are part numbers 21013315 and 21013316.

For some reason my 97 Saturn SL1 doesn't have any such plug or access hole in the backing plate--

[steve seibel]

Still puzzling this over-- trying to sum up all the questions I still have--

1) So I want to set the adjusters in the brake drums so that there is a *slight drag* on the brakes -- and this adjustment is made with the parking brake handle *down*, right?

2) Doesn't this in essence mean the brakes are dragging when I'm driving? That's not a problem?

3) So, at present, I can't stop the car from rolling with the *parking brake*. There's *some* resistance to rolling, but I can still push the car. So what is stopping the handle from just rising a few inches higher-- a few clicks higher-- when I pull on it? It's nowhere near how high it can go if I set the adjustment nut to the full loose position. (It's in the full tight position now.) Is there something about the geometry of the cables from handle to the brake drums (thanks for the photo btw) that puts a limit on the total travel of the cable which is *independent* of whether or not the shoes are being pulled tightly against the drums, and also is *independent* of whether the handle mechanism has risen to the highest possible position that you would get with the adjuster nut full loose (all the way up)? Can someone explain how what that limit is?

Thanks--