Jump to content
SAU Community

Help :( R32 Hard Brake Pedal, Can't Find Out What It Causing It.

Ten Four

By Ten Four,
in Western Australia

 Share

Recommended Posts

Ten Four Grand Master

Ten Four

Posted
Posted

Heres the story:

Bought an unreg R32 GTS4 that had been sitting for a while. And now it wants to go over the pits and has failed twice for a hard brake pedal. So far this has been done:

Brakes bled

Front & Rear calipers reconditioned

New pads fitted

Master cylinder reconditioned

Rotors skimmed

Brake booster pressure tested

The brakes react to first part of pedal travel but go solid when trying to press hard, ie in a emergency stop. This is why pits said they won't pass it.

NOTE: Car has factory ABS fitted.

So far, can't get rid of the hard pedal. Beginning to suspect while booster has passed pressure test, it is miss-performing. Has anybody got one that they can lend me to test? Or if it comes to it, anyone have a good condition one to sell?

Anybody had this problem before? (Rmb ABS fitted)

0431 985 155 is my dad's phone number (Tony).

(I'm still on Ls)

Ashy Larry Grand Master

Ashy Larry

Posted
Posted

Sounds like air in the system,

But if you have bled them, it should of corrected the problem.

There is a particular way you bleed the brakes with ABS as well.

Not sure if that is just for GTR though.

Other than that, I am stumped!

Ten Four Grand Master

Ten Four

Posted
  • Author
Posted (edited)

Yeah, it's been done by my mechanic who used to do ferraris lambos tractors :thumbsup: (ex-barbagello) etc etc, basically fixes anything, except my line!

It doesn't feel like air cause if just driving normally, they are fine. Its when you brake to a certain point that it becomes rock solid and you really have to press hard for the car to stop. (Don't get me wrong, it stops really well, its just the hard pedal) The guy at the pits said sure, your average joe could stop the car, but he's referring to when say eg a girl is driving and they can't press the pedal, ie making it too dangerous.

I want the car on the road :| This is the only thing stopping it and its starting to annoy the hell out of me. Stupid skylines :P

Edited by Ten Four
NA_Goodness Grand Master

NA_Goodness

Posted
Posted

Doesn sound like air in the system, that gives the opposite effect. You put your foot an the brake and nothing happens for a while because you're compressing the air.

Sadly, I cant think of what it might be.

Ashy Larry Grand Master

Ashy Larry

Posted
Posted

Rhys,

Air in the system can in fact cause block peddle mate,

I understanded where you are coming from,

But to discount air from the system completely at this stage, may in fact lead you down the incorrect path.

There is a sequence that you have to bleed the brakes with ABS in a skyline if it is to be done properly.

There is write up for this in the GTR Manual that can be found online.

Once you have cleared the system completely, then can you move onto the next fault finding excercise.

Nav had a very similiar issue with his car.

Cheers

Mike

Ten Four Grand Master

Ten Four

Posted
  • Author
Posted (edited)

Thanks for the replies guys.

Flash, it's not much different, both on and off are pretty hard.

Mike, where is this guide? Otherwise the air has been pretty much discounted at this stage. Its acting more like the booster so I'm going to try get one (to a point its fine, after that its just hard). Cause the car still stops really well, its just the firm pedal.

Defective, the lines are not twisted or split cause each was tested. Brake fluid was replaced earlier today.

Ahh 33, I think I may just do that, thanks.

Edited by Ten Four
Onthehunt Veteran

Onthehunt

Posted
Posted

Have you tried taking it and stopping by a couple of performance workshops to get their opinion on what it could be? They might have come across this issue before and know the solution.

Ten Four Grand Master

Ten Four

Posted
  • Author
Posted

Yeah mate, as a last resort I will probably end up taking it to a performance workshop. I'm sure the problem is something silly. If the brake boosters I've just bought and the disabling the ABS don't fix it, I'll take it to one.

Dsturbd Grand Master

Dsturbd

Posted
Posted
The brakes react to first part of pedal travel but go solid when trying to press hard, ie in a emergency stop. This is why pits said they won't pass it.

Who idea was it to do the above mentioned repairs ??

Get a Brake specialist to check it out . ( a good one also )

TAKUSHI Proficient

TAKUSHI

Posted
Posted
Rhys,

Air in the system can in fact cause block peddle mate,

I understanded where you are coming from,

But to discount air from the system completely at this stage, may in fact lead you down the incorrect path.

There is a sequence that you have to bleed the brakes with ABS in a skyline if it is to be done properly.

There is write up for this in the GTR Manual that can be found online.

Once you have cleared the system completely, then can you move onto the next fault finding excercise.

Nav had a very similiar issue with his car.

Cheers

Mike

Mmm i know you might be the guy who gave me the warn on this but ima have to say fail on that one aye, as a mechanic i can say that air in system will cause a spongey pedal and lesser response upon application

Its sounding more like booster but also check where the vacuum line connects to the manifold, start it with that line off and make sure its sucking in air, also check that the booster vacuum hose isnt sucking closed under vacuum when you push the pedal

Ten Four Grand Master

Ten Four

Posted
  • Author
Posted (edited)

Dsturbed, the car had been sitting for 1.5 years so the above jobs were done as to be expected. However, it didn't change the brakes much.

Takushi, that has been done a few days ago.

Update: it isn't the ABS.....

Edited by Ten Four
NISMOGTT Collaborator

NISMOGTT

Posted
Posted

Hey might sound odd but can you post up a pic of the brake booster....

i had a brake specialist test my old TX-5 booster and it was fine then i had the same problem..

i found there was a one way valve in the booster due to boost and it was the wrong way around :D so please check you dont have one or it is the right way around.... also you say you tested the line,,, did you actually start the car with a vacume tester on it then rev to boost to see the difference?? and what was the difference??

Ten Four Grand Master

Ten Four

Posted
  • Author
Posted (edited)

Hi guys, problem seems to have been solved.

Previously, the master cylinder must have been taken apart as a washer was missing and the piston was bigger than usual (looked like nothing was out of place...). Replaced washer and put a shorter piston and it seems to have solved the problem. In essence, the car still brakes just as well as before, just with a softer pedal now.

Will be visiting the pits tomorrow.. Cheers.

Edited by Ten Four
Guest
This topic is now closed to further replies.
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      So I mentioned the apprentice, @LachyK helped take the bonnet off. We just undid the nuts on the hinges and unclipped the gas struts, then pulled the bonnet back a little as the front was catching on the front bar.  I had a good look at everything today and have removed the rams, repaired/reset the hinges and bolted it back together like it never happened. I'll do a separate write up on the repair, and I also removed the poppers from the Fuga today too to save grief down the road.....as said above it is at least $5k to repair retail. I'm also happier about my ability to prepare a race car, and less happy about Nis-nault's engineering (I can hear @GTSBoy sAfrican Americaning) because the top hose of the radiator didn't slip off.......it snapped clean off. By practice I put the hose clamp hard up against the flare on a neck to make it least likely to ever move (thanks @Neil!). I guess that puts a little more pressure on the end of the pipe as it is further away from the rad, but still, that is pretty shit. I've put it back on for now as there was a fair bit of neck still there, but obviously there is no lip on the neck any more so I don't think I'll track it again until I have a new rad. Speaking of which....more research required. It looks like Koyo makes a standard size radiator in ally which I'll grab in the meantime, but I really want something thicker so might have to go custom in the medium term (ouch) Coolant still needs a refill and I have the pressure tester on it over night, but other than a wash down of the engine bay it seems alright. And @MBS206 noted something noisy on the front of the engine and I think I agree....time for a new accessory belt and tensioners I think.
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      our good friends at nismo make a diff for it, I have one (and a spare housing to put the centre in) on the way. https://www.nismo.co.jp/products/web_catalogue/lsd/mechanical_lsd_v37.html AMS also make a helical one, but I prefer mechanical for track use in 2wd (I do run a quaife in the front, but not rear of the R32)
    • GTSBoy
      R33 persistent issues. P/steering and lag/misfire

      By GTSBoy · Posted

      What are we supposed to be seeing in the photo of the steering angle sensor? The outer housing doesn't turn, right? All the action is on the inside. The real test here is whether or not your car has had the steering put back together by a butcher. When the steering is centred (and we're not caring about the wheel too much here, we're talking about the front wheels, parallel, facing front) then you should have an absolutely even number of turns from centre to left lock and centre to right lock. If there is any difference at all then perhaps the thing has been put back together wrongly, either the steering wheel put on one spline (or more!) off, and the alignment bodged to straighteb the wheel, or the opposite where something silly was done underneath and the wheel put back on crooked to compensate. Nut there isn't actually much evidence that you have such a problem anyway. It is something you can easily measure and test for to find out though. My money is still on the HICAS CU not driving the PS solenoid with the proper PWM signal required to lighten the load at lower speed. If it were me, I would be putting either a multimeter or oscilloscope onto the solenoid terminals and taking it for a drive, looking for the voltage to change. The PWM signal is 0v, 12V, 0V, 12v with ...obviously...modulated pulse width. You should see that as an average voltage somewhere between 0V and 12V, and it should vary with speed. An handheld oscilloscope would be the better tool for this, because they are definitely good enough but there's no telling if any cheap shit multimeter that people have lying around are good enough. You can also directly interfere with the solenoid. If you wire up a little voltage divider with variable resistor on it, and hook the PS solenoid direct to 12V through that, you can manually adjust the voltage to the solenoid and you should be able to make it go ligheter and heavier. If you cannot, then the problem is either the solenoid itself dead, or your description of the steering being "tight" (which I have just been assuming you mean "heavy") could be that you have a mechanical problem in the steering and there is heaps of resistance to movement.
    • MissMintyR33
      R33 persistent issues. P/steering and lag/misfire

      By MissMintyR33 · Posted

      Little update  I have shimmed the solenoid on the rack today following Keep it Reets video on YouTube. However my steering is still tight. I have this showing on Nisscan, my steering angle sensor was the closest to 0 degrees (I could get it to 0 degrees by small little tweaks, but the angle was way off centre? I can't figure this out for the life of me. I get no faults through Nisscan. 
    • Dose Pipe Sutututu
      Dose's Sometimes DIY and Pay Someone Home & Boat Improvement Thread

      By Dose Pipe Sutututu · Posted

      The BES920 is like the Toyota Camrys of coffee machines. E61 group head is cool, however the time requirements for home use makes it less desirable. The Toyota Camry coffee machine runs twin boilers and also PID temp control, some say it produces coffees as good as an E61 group head machine.
×
×
  • Create New...