Mechanics

BRAKE ISSUE

2000 Saturn SL2 • 110,000 miles

Hi, I have a 2000 Saturn SL2 I recently bought used. I am having a brake issue. The car most likely sat around for a long time before I bought it. The brakes were serviced the week before I bought it, new front pads and rotors. I drive about 25 miles to and from work. In the morning the brakes work fine. In the afternoon on hot days there is a problem. The brake pedal gets firm and both front brakes feel like they are dragging/engaged when my foot is off the pedal. Both front rims are getting hot to the touch at the end of my ride, and I noticed that when I coast down hill I am slowing down. The back rims do not get hot.

I have replaced both front brake lines, both front brake calipers and flushed the master cylinder/front brake lines with new fluid. The problem has not changed. I am getting (what feels like) a good vacuum at the brake booster and the brake booster check valve is working properly. When I disconnect the vacuum line from the brake booster and plug it, I get a similar feeling firm brake pedal but the front brakes are releasing (note: I need to test this more on a hot afternoon).

I have a second Saturn SL2 and I am thinking of swapping the brake boosters to see if there is a difference. Do you think that this is a good idea?

I don't want to replace more parts without determining the source of the problem. How do I proceed with this?

Thanks for the help! Bill



Avatar
Beeberz
August 8, 2012.



Check to see if you have free play between pedal and booster push rod.

KHLow2008
Aug 8, 2012.
Just to add to this one I really doubt its the brake booster causing the brakes to drag. Also of course the front rims are going to get warm the brakes are stoping the car. The front is also going to get hotter then the rear because they do 70 percent of the braking. Also if the rear brake shoes are not adjusted correctly then the fronts are doing even more then 70 pecent of the braking. Which usually the rear brakes are never adjusted correctly because no one ever adjusts them.I wouldnt say the front brakes are draging just because the front rims get warm.I have a 1999 saturn and my front rims get warm after driving and my brakes arent dragging.I would actually make sure there draging after driving out the car on jack stands and see if any of the wheels are dragging front and rear?

Saturntech9
Aug 8, 2012.
Just to be clear, am I checking the free play between the brake pedal and the push rod/brake switch inside the car or the free play between the push rod and the master cylinder inside the engine compartment, or both?

I understand that the front rims get warm from braking, but the rims are getting hot enough to burn you and I find that unusual. Also slowing down going downhill is a red flag for me. I will try to reproduce the issue and spin each wheel.

Tiny
Beeberz
Aug 8, 2012.
I can even think of the last time I saw a brake booster cause the brakes to drag in the over 16yrs working for saturn. It far more likely if they were draging it would be the master cylinder causing it. Do this see if the brakes are dragging like I told you and if they are unbolt the master cylinder from the booster its only two 15mm nuts. If the dragging stops then you know its in the booster pedal area. If not you know its not in that area. The most common reason I have seen for brakes dragging is from someone putting the wring brake fluid in the master cylinder causing all the seals in the brake system to swell and trap fluid pressure.

Saturntech9
Aug 8, 2012.
Thanks! Okay, I loosened the brake light switch to make certain the pedal has full travel - it does. There is adequate free play between the pedal and the push rod. What do I do next?

Tiny
Beeberz
Aug 11, 2012.
Was the brake switch restricting the pedal return?
If yes, and you have free travel now, go for a test to see if the brakes drags.

KHLow2008
Aug 11, 2012.
You never checked to see if the wheels were dragging like I asked you too?If you find them dragging unbolt the master cylinder like I asked you too and pull it away from the brake booster. Theres only two 15mm nuts holding it on then see if the drgging goes away. Thats where you need to start also now you brake switch is going to be out of adjustment one way or another. The early saturns had the switches out of adjustment from the factory way before your car was made. Causing a slight drag not noticable but causing drums and rotors to warp.

Saturntech9
Aug 11, 2012.
I let the car sit until the weekend as I didn't want to get stranded. I loosened the nuts on the master cylinder and put washers between the brake booster and the master cylinder. I've been driving the car for 2 days and there are no issues so far, the front rims are not heating up.

The washers are a bit thick and there is more pedal travel than I would like to feel, so I will look for thinner washers.

Tiny
Beeberz
Aug 15, 2012.
So the problem is in the brake booster or brake pedal. Washers is not the answer. Please put the car on jack stands spin the wheels to feel the drag. Then unbolt the master see if the drag goes away?If it does then bolt it back up then unhook the rod from the brake booster to the brake pedal see if its still dragging?Even with washers it could still be causing the brakes to drag. Also I would never shim the master cylinder like that.

Saturntech9
Aug 15, 2012.
The car was put on stands. The master cylinder is bolted directly to the booster. The back wheels spin freely. The front wheels spin with some resistance. I can hear the brake pads contacting the rotor. The front wheels spin just less than one half revolution with one push.

I loosened the master cylinder nuts one turn and rechecked. The back wheels spin freely. The front wheels spin with some resistance. I can hear the brake pads contacting the rotor. The wheels spin between one half revolution and three quarters revolution with one push, slightly more than when the master cylinder is bolted tight.

The washers have been removed from between the master cylinder and the booster.

What is the next step here?

Tiny
Beeberz
Aug 19, 2012.
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