GTV 2.0 Break problem

Started by AlfaHolic, October 07, 2008, 05:14:00 PM

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AlfaHolic

Hi i just got my new gtv 2.0 the problem is the breaks feel like absolute crap they feel like the booster is not working i cant hear it leaking though is there any other ways too test them. I did a search but didnt find much, Thanks
Lars

greengtv8

Hi there, there is a few things it could be, to check, but first need to know whats happening!
     Is your brake peddle -Hard or soft?
                                 -High or low?
     
     Does the brake peddle pump up? Or sink when applied slowly?
     
     Is your handbrake high or low?
   
Or when you say that they're crap, do you mean when driving?
     Vibraites or makes noises when braking?
     Car pulls to one side when braking?

Most common is rear brakes in need of adjustment, which will bring the peddle up and handbrake back down to a few clicks, and also crap fluid, be it full of moisture or air bubbles, and in need of a full bleed and flush.

However, if you want to test your brake booster:-
      With the engine off, press the brake peddle a dozen times or so to remove static vacuum.
      Then, with one foot pressed fermly on the brake peddle, start the engine.
      If the booster is working, the peddle should pull down a little more as the engine vacuum pulls on the booster.
Little green Alfetta gtv 1982
Fitted with:
Lexus V8 4Ltr
Supra w58 g/box
LS400 IRS rear susp.& 8 1/2' diff
Coil over's all round
Nissan R32 Front brakes
Peddle box,balance bar & adj.bias valve's
9 point roll cage(inc. engine bay)
Custom Extractors & exhaust
Custom body kit & under tray

AlfaHolic

Yeah the brakes pedal has a really hard feel the pedal is high, it doesent sink when applied stays where you push it too. The handbrake is high. The brakes dont viabrate or make noises how ever under hard braking it does pull slightly too the right and when i did a brake test (jumped on them hard) the front right locked but not the left, i will clean the pistons on the right caliper when i have the time but the even with that i would have though the rest should be able too pull it up eaiser then it does. With all the static vacumn gone it does slightly sink when started with foot on brake.
Thanks Lars

greengtv8

Looking at the few things you said, i'd say the chances are that you may have a few little problems...
     Pulling to the right, and able to lock the right, says that the right front caliper is working, but the left is not(or atleast not as much as the right). Most common problem here is usually an old brake line. The rubber brake line colapses inside after many years, and the fluid has problems getting through.
     By jacking up the front to get wheels off the ground, spin the wheel by hand while someone else applies the brake. If the brake is slow to grab and or release, then most likely will be the rubber brake hose. A sticky or jammed piston is usually shown by only wearing out one brake pad in the caliper.

     Handbrake being high is a case of manually adjusting the rear brakes. This is done at the rear calipers, not the hand brake cable!

     Lastly, if the booster is working and the peddle is high, and after the front left brake is checked, poor braking can sometimes be as simple as having bad pads! I'm not sure what everyone else runs, but i've got Mintex in my road car, and they are excelant.
     P.s. If you don't know when your brake fluid was last changed, i would recomend changing it and giving the system a flush. Is cheap and should be done every 2 years as moisture get in and lowers it's boiling point.

     Hope this helps...
Little green Alfetta gtv 1982
Fitted with:
Lexus V8 4Ltr
Supra w58 g/box
LS400 IRS rear susp.& 8 1/2' diff
Coil over's all round
Nissan R32 Front brakes
Peddle box,balance bar & adj.bias valve's
9 point roll cage(inc. engine bay)
Custom Extractors & exhaust
Custom body kit & under tray

AlfaHolic

Thanks for the help green im just waiting on some caliper rebuild kits do them flush the system new pads and go from there.

AlfaHolic

Thanks mick, one question how do i go about adjusting the rear brakes/handbrake?
I have new pads in the front now, the rebuild kits are only 20 bucks a side so its not too expensive

greengtv8

Little green Alfetta gtv 1982
Fitted with:
Lexus V8 4Ltr
Supra w58 g/box
LS400 IRS rear susp.& 8 1/2' diff
Coil over's all round
Nissan R32 Front brakes
Peddle box,balance bar & adj.bias valve's
9 point roll cage(inc. engine bay)
Custom Extractors & exhaust
Custom body kit & under tray

Sheldon McIntosh

Quote from: greengtv8 on October 12, 2008, 05:18:13 PM
http://www.alfaclubvic.org.au/component/option,com_smf/Itemid,68/topic,1732.0/

Haha.  Welcome to the forum greengtv8, It's great fun repeating yourself over and over and over again isn't it?

I found I had to adjust mine so they were just touching and then tightening the lock nuts there.  If I had it just touching, and then backed off even the tiniest amount the handbrake would come up about 8 clicks.  Any thoughts?