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308 pulls to the right under braking

Discussion in 'Technical Q&A' started by brent Lachelt, Mar 4, 2004.

  1. brent Lachelt

    brent Lachelt Formula 3
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    Dec 6, 2003
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    Glendora,California
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    Brent R.Lachelt
    My 1982 308 gtsi is pulling more to the right under braking. Not fun at high speed and heavy braking. Both front calipers have been rebuilt and the brake lines look fine. I wondering if the left rear caliper needs adjusting? Specifically making sure that the inner and outer pads are .01mm away from the rotors. If the left rear caliper isn't adjusted to that .01mm couldn't the car pull right if the right rear caliper was adjusted correctly?

    Thanks,
    Brent
     
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  3. jmillard308

    jmillard308 F1 Veteran
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    May 29, 2003
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    John Millard
    Brent
    More likely wheel alignment or tyre pressures
    John
     
  4. bert308

    bert308 Formula 3
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    Nov 30, 2002
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    Bert Kanters
    My 308 did that. With new brakepads everything is allright, but after a certain amount of wear, it starts pulling to the right. I guess there is some kind of spot on the brake piston that is reached when the brakepad is getting thinner. I have to rebuild the caliper, will do it soon. The rear caliper adjustment has not that much effect, adjust the pads in a way that you can feel a little play, further adjustment should go automatic. For the yearly test I always have to adjust the pads real tight to the discs, otherwise the car is not passing the test due to insufficient handbrake power.
    If you want to find out if it is alignment/tire pressure OR due to the brakes itself, push the pedal until the brakes lock, if right locks before left the problem is with the brakes.
     
  5. Steve Magnusson

    Steve Magnusson F1 World Champ
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    Jan 11, 2001
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    Brent -- Certainly make sure the rear calipers aren't dragging (but the clearance should be ~0.1 mm not .01 mm). Did you check the play in the front wheel bearings when you did the brake work?
     
  6. brent Lachelt

    brent Lachelt Formula 3
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    Steve you are right I mean't to put .1mm instead of .01mm. The rears where set to .1mm and aren't dragging. The front wheel bearings were replaced when I had the brake work done. To Bert's point the pads were changed about 8000 miles ago and when I got the car back it wasn't as pronounced as it is now. However, let me back up in the story. The other day, prior to this problem getting worse, I put wheel spacers 55mm on the front to fill out the fender a bit more. When I got home after noticing this problem, much worse, I took the spacers out and also bleed the brake system too. I did get a far amount of air bubbles out of the left front caliper. I then took the car out and the problem was not as bad as before. What do you think?
     
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  8. Steve Magnusson

    Steve Magnusson F1 World Champ
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    Jan 11, 2001
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    Increasing the front track (via spacers) will increase the twisting moment that the A-arm bushings must resist to prevent the front wheels from "toeing out" under braking so if they are toeing out unequally under braking (for some other reason) you'd get more directional change with the spacers (did you really mean 55mm spacers? -- seems overly huge).

    Although your front wheel bearings were replaced, it never hurts to give them a 12 o'clock/6 o'clock rocking feel whenever the opportunity presents itself IMO.
     
  9. brent Lachelt

    brent Lachelt Formula 3
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    Steve, thanks for the input. The spacers are 15mm not 55mm. I guess I need to proof these messages better before I send them. Again many thanks!
     
  10. ham308

    ham308 Formula Junior

    Nov 3, 2003
    358
    NE Switzerland
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    Richard Ham
    Mine does this slightly. I always put it down to the fact that there is a small amount of play in the right hand side of my steering rack. Might be wrong of course.

    I'm planning on fixing it sometime, but it's fairly low on the list at the moment.
     
  11. Hubert

    Hubert F1 Rookie

    Jan 3, 2002
    2,642
    The Left Coast
    Are you front crossmembers bolts tight and torqued? I had a similar pull to the right, and when I checked the crossmember, the bolts were loose; play in the cross member will cause pull under braking.
     
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  13. brent Lachelt

    brent Lachelt Formula 3
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    Hubert,

    I 'd like to check that out. Are you talking about the bolts that hold the steering rack? A-arm bolts? Where exactly are the cross member bolts

    Thanks
     
  14. nautique

    nautique Rookie

    Nov 1, 2003
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    Craig Tempelton
    Brent,

    I had the same problem after I rebuilt my calipers. I finally took the car into a shop and had them bleedmthe calipers on a presure system and the problem was solved. I could not get the air completely out of the calipers with a vacume pump.
     
  15. Paul_308

    Paul_308 Formula 3

    Mar 12, 2004
    2,335
    Was reading these posts as I used to have that occur occasionally but now that my memory has jogged, (no easy task) I recall, it pretty well stopped when I had the rack changed. It wasn't all the time but more often at the beginning of a drive. The rack's right bushing was gone. (if you replace your rack, don't get a rebuild - been there regretted that)
     
  16. Wayne 962

    Wayne 962 Formula Junior

    Nov 27, 2003
    434
    Brake lines may look fine on the outside, but may be clogged on the inside. The lines are usually the first thing I look at replacing when the car is pulling (caliper is sticking). The theory is that the lines become constricted, and then they won't release the pressure when you let off of the brake. Not entirely your situation, but the lines indeed are the most vulnerable part in the system, in my opinion...

    -Wayne
     
  17. Harry

    Harry Karting

    Nov 1, 2003
    89
    Germany
    Even if brake hoses look fine, they can still have a reduced inner diameter due to ageing rubber (the car is >30 years). I would change all hoses if not been done. Cured a similar problem in my car.
     
  18. jbcottrell

    jbcottrell Rookie

    Apr 8, 2004
    31
    I had the same problem. Strangely I found that he tie rod ends were loose. Tightened them up and the pull was gone! It sounds strange but it's certainly worth checking. It worked for me.
     
  19. CarlH

    CarlH Karting

    Feb 5, 2004
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    MD
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    Carl H.
    Same deal with my 308, but only intermittently. Has to do with the vehicle dynamics and wheel position going into breaking. Same off ramp - same pulls right result, other times no pull. Based on that I was guessing the known (common) issue of slop in the right side of the rack.
     
  20. pma1010

    pma1010 F1 Rookie

    Jul 21, 2002
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    Philip
    I had the same thing coming back from hte track. Turns out the problem was the "junction box" in the braking system under the front lower cover. In my case the effect was pronounced on gentle braking rather than when you nailed the brakes.

    Start with the easy stuff, bleed the brakes fully, check the tire pressures etc as others have advised. Then you can do more diagnosis on pedal pressure, turning right, turning left, feel of the brake pedal (vibration etc) to be able to get a better sense of what's going on.
     
  21. joeyy

    joeyy Karting

    Nov 11, 2003
    190
    long island
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    joe
    Wayne at Pelican parts probably hit it on the head. if the calipers had to be rebuilt. than the hoses and all lines have to be replaced they are all part of the same system and are of the same age. they do get cloged.no use changing just the left sides you might as well do them all.
     

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