1996 VS Commodore brake problem

[alanajpm12]

I have a 1996 VS Commodore Berlina that I am having trouble with concerning the brakes.
Over the last couple of months the brake pedal has been intermittently very hard (without much travel) or with normal travel in the brake pedal. When the brake pedal is very hard I notice that it doesn’t take very long for the temperature gauge to show that the engine is overheating. I assume that the brakes are being applied and the car is driving against the brakes….very frustrating.
I only have to drive 50 metres from my home to realize which of the above scenarios are happening.
I have taken my car to my usual mechanic who checked all calipers hoses etc, all ok . He decided to replace the booster as he thought this may be the problem. All was ok for about two days but all reverted back to previous problem. I have disconnected the ABS module but this has had no effect at all. I’m loathe to take it to my Holden dealership for them to sort it out with the resultant cost of a mystery problem.
If anyone has any ideas regarding this problem I would greatly appreciate any assistance

[Brett_jjj]

Mate, Id say you might have to take it to someone (holden?) with a scantool that can connect to the ABS system to get it checked out to make sure its all working and has no error codes logged.. You can check for logged ABS codes yourself,its similar to checking the error codes for the ECU,but you bridge pins 5 and 12 on the ALDL connector ,this will flash up the codes on the ABS dashlight.A continuous code 12 is what you want,it will flash once,then a pause,then flash twice-code 12,let it go for at least 20 seconds or so just to be sure.I also would have said it was the booster going from what you have described,but if its been replaced,then it gotta be elsewhere,unless the new booster is faulty.Id also try a new master cylinder.They can cause all sorts of different problems if they arent in good working condition,so thats something to keep in mind also.Seized calipers can also be another cause,and its pretty common on these cars,especially the rears.One last thing I can think of is a vacuum leak arounnd the engine or vacuum hoses etc.It will cause the engine to run hotter because it will run leaner because of the leak,so that could also explain the higher engine temps and the hard brake pedal from little or no vacuum available.
A list of ABS error codes.
12 Diagnostic system operational
21 Right hand front wheel speed sensor fault
23 Right hand front wheel speed sensor continuity fault
25 Left hand front wheel speed sensor fault
27 Left hand front wheel speed sensor continuity fault
28 Wheel speed sensor frequency error
31 Right hand rear wheel speed sensor fault
33 Right hand rear wheel speed sensor continuity fault
35 Left hand rear wheel speed sensor fault
37 Left hand rear wheel speed sensor continuity fault
41 Right hand front inlet solenoid valve circuit fault
42 Right hand front outlet solenoid valve circuit fault
45 Left hand front inlet solenoid valve circuit fault
46 Left hand front outlet solenoid valve circuit fault
55 Rear inlet solenoid valve circuit fault
56 Rear outlet solenoid valve circuit fault
61 Pump motor relay circuit fault
63 Valve relay circuit fault
71 ABS control module internal fault

[Darcon666]

As Brett_jjj says... take it to someone that as the ability to hook up the car to a scantool.(Good list of codes Brett_jjj)

The days of the local guy/mechanic being able to fix our modern cars is long gone, especially when electronic Fuel Injection and onboard ECU where introduced.

[hako]

It should not be anything to do with the ABS I'd say, and for 2 reasons - first, if faulty it should cause the ABS warning light to come on, and second, if the ABS is activated, you will not mistake as it makes a lot of noise and makes the brake pedal vibrate.
I'd say it it either one or more caliper pistons sticking or the caliper slides sticking and not releasing the pressure on the pads - this heats the discs up and causes drag which makes the engine work harder to overcome the drag....and gets hot. In rare cases, the flexible brake line to the caliper can fail internally and prevent the brake fluid from returning and releasing the brakes - basically acting as a one way valve. It could possibly be the master cylinder but if it was you would notice the brake pedal not returning to it's normal position after braking.....so I put my money on piston or slides or both.
You can easily find which calipers are sticking by driving the car then feel each wheel - the hot one(s) will have the problem.
That's my guesses.

[RX25SE]

Im going with a blocked compensating port in the master cylinder. This would not allow the line pressure to return to atmospheric when the brakes are released and the build up of heat in the system would begin to apply the brakes.
You could test it by cracking a brake line at the master when it's playing up. If this is the fault then asmall amount of fluid will escape and the brakes should return to normal, until the pedal is pushed again.

Or what hako said.

The days of the local guy/mechanic being able to fix our modern cars is long gone, especially when electronic Fuel Injection and onboard ECU where introduced.

I disagree. I've seen plenty of local blokes that are better than a lot of dealer mechanics. They have to think more as they are working on various makes/models. Mind you, I've seen some fine dealer mechanics as well.

[justbad4you]

Ask krisp he knows it all???? Or so he thinks

[Darcon666]

I disagree. I've seen plenty of local blokes that are better than a lot of dealer mechanics. They have to think more as they are working on various makes/models. Mind you, I've seen some fine dealer mechanics as well.

First of all I never mentioned dealers

Secondly, I have had 3 Holdens from new... 1 I still have... and the first "NEW" VT SS SII I had went for the first service to one of the biggest Holden Dealers in Sydney. When I went to pick it up the a55hole of a "Senior" Mechanic was pouring oil into the engine(As I could see it from the waiting room....) were the oil was just pouring out of the bottom cause the carnt forgot to put the sump plugg back in.

After that NONE have gone to a dealer for there any service as I reckon they are all shite. to all dealers.

Thirdly.... I agree with you that mechanics, outside of dealers(The local mechanics/guys...) are far better... but you need to find the good ones, with the appropriate tools and knowledge to use said tools to diagnose the issues in our modern vehicles... that's what I meant to say.

[justbad4you]

Ask krisp he knows it all???? Or so he thinks

[RX25SE]

First of all I never mentioned dealers

Fair enough. It's just that between the local blokes and dealers there's not much else. Except the franchise operators.

... but you need to find the good ones, with the appropriate tools and knowledge to use said tools to diagnose the issues in our modern vehicles... that's what I meant to say.

Agreed.

[bpefi]

Im going with a blocked compensating port in the master cylinder. This would not allow the line pressure to return to atmospheric when the brakes are released and the build up of heat in the system would begin to apply the brakes.
You could test it by cracking a brake line at the master when it's playing up. If this is the fault then asmall amount of fluid will escape and the brakes should return to normal, until the pedal is pushed again.

Or what hako said.



I disagree. I've seen plenty of local blokes that are better than a lot of dealer mechanics. They have to think more as they are working on various makes/models. Mind you, I've seen some fine dealer mechanics as well.

A blocked compensating port would just lock the brakes on - its happened to me twice - once in a HJ Holden & once on a motor cycle - the HJ just got slower & slower until it just stopped with the brakes locked on. The motorcycle brakes came on that quick it locked up the front brakes & tipped me over the handlebars. I would be looking at the basics first & working your way up.

As for mechanics & the local Guy - people need to support these guys as usually they are the only ones that really know anything as a rule. Most techs on the floor in dealerships just change oil - yes there are some good ones - but if it was like it was for me as a foreman in a very large dealer group in Brisbane - there was one guy on the floor doing all the technical stuff & the rest of the staff where mostly apprentices. Anyone in business for themselves has scanners & even the knowledge to change how you car runs - by tuning the ECU. That's not something a dealership can do.. Anyone with a brain usually goes into business for themselves...

[RX25SE]

Happened to me in my Gemini.
Just caused brake drag.

[alanajpm12]

Many thanks for all the suggestions.
I have just checked the error codes for the ABS module. Code 12 first flashed but then Code 63- Valve Relay Circuit fault followed soon after.
I haven't checked tha Master Cyclinder as yet , but I will over the next couple of days.
I have obtained a second hand and fully tested ABS module since I was quoted between $1850-1870 for a new replacement from the local Holden Dealerships. Should I attempt the to install the second hand module myself and how easy/difficult a job is this, or should I take it to mechanic or Holden dealer. I would assume that the dealer would not install second hand parts.