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]

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?

[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?

[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.

[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--

[trottida]

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.

Here is the diagram showing the backing plate. I just came across it.

[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--

[trottida]

Originally Posted by steve seibel

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?

Yes, back off the adjustment screw a bit and the parking brake should be fully down. Adjust the shoes using the star wheel till there is a slight drag when rotating the drum by hand.

Originally Posted by steve seibel

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

The brakes will drag at first and they will settle. Shouldn't be a problem to be concerned about.

Originally Posted by steve seibel

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--

I think the limitation is the length of the cable itself. It basically controls a leaver at the drum that compresses the brake shoes. The cable is at full stretch and it's still not enough to compress the shoes. As I understand it, you have to adjust the shoes to counter that.

If you have ever worked on a pedal bike with hand brakes (with cables not hydraulic) you can relate it to that. There is an adjustment at the hand brake to tighten the pads and when that adjustment is fully consumed you have to go to the brake pads themselves and shorten the cable length.

..

[billr]

Post some pictures of that brake stuff, both sides, with the drums off. Better yet. post videos showing how things move as you raise the hand-lever.

[steve seibel]

It's being suggested to me that if the parking brake cable is set too *tight* at the adjustment nut by the handle, then when the parking brake is pulled there might not be enough motion of the mechanism inside the brake drum to advance the little adjusting wheel.

I'm skeptical--

Is there any way this could happen, at least assuming the cable isn't adjusted so tight that the parking brake is actually dragging with the brake handle all the way down? (Which it doesn't, even with the adjustment nut screwed all the way down. And the handle does come up 5 to 7 clicks with a moderate pull, like the Haynes manual suggests.)

Or is that not a viable theory?

Will probably have the drums off again soon and will get some photos or videos--

Thanks--

[fetchitfido]

Probably not where the issue is: Adjusting at the handle: https://www.youtube.com/watch?v=NatVQFa5zdM
Probably where the issue is: Adjusting at the drum: https://youtu.be/FpxQN2esZnU?t=370

The other option, if the shoes & springs are in good shape and adjusted properly is the cables have lengthened from wear. Should be easy to find them as long as it's not a '91-'96 2dr with rear calipers.
You might be able to see where the load-leveler off the handle attaches to the p-brake cables with the handle shroud off, maybe it's bent or the cables are falling out (if you can't see then the console needs to come out if you want to check).