Master Cylinder Difference SS vs Redline

[SanchezCBR]

Hi Everyone.

Just for some background info.

I have a VE SS 2008 Wagon that I upgraded the Front brakes to Brembo's and DBA T3 rotors.

After installing them 6 months or so ago I was never fully happy with the results. The pedal did not feel firm and to get the car to pull up after carrying any speed I had to stand on the pedal.
I thought long and hard about it and on the weekend I replaced the factory pads that came with the callipers with QFM Performance pads and completely flushed the brake fluid. Back and front.

Although there is a difference in the feel of the pedal it still doesn't feel firm like I would expect it to. However it is no longer as spongy as it was.

After talking to a mechanic on the weekend, he told me that it could be possible that the master cylinder and possibly even the brake booster might not be big enough to move the volume of fluid in the brembos to really get them working to full capacity.

I've looked online for images of the master cylinder and booster on a Redline and it reservoir definitely looks bigger than the one on my car. I can not find any part numbers to compare either.

So, for people in the know, is there a difference in size of the master cylinder and booster in the Redline as compared to the SS? If you can post some photo's of them that would be great.

Thanks in advanced.

 

[SanchezCBR]

I just spoke to Gentech in Mitchell about this and they advised that there are 2 things that need looking at. Firstly are the break lines. They recommend replacing all the brake lines with braided lines as the standard rubber lines would add spongyness to the feel of the pedal and secondly they said that when you bleed the brakes on the VE commodore the ABS unit needs to be cycled electronically as it can have air in it from changing the callipers. They said that only Holden and themselves have the machine that can do that. I must say I have never heard of that before. In all the upgrades they have done they have never needed to upgrade the master cylinder.

Regardless, I was under the impression that the Factory Redlines have rubber brake lines and don't have an issue with a spongy pedal. To be honest, the extra money I am needing to throw into this is making me think I would just put it back to original and leave it alone.

 

[illlusion]

Any one with a tech 2 can cycle the abs while bleeding if that helps as far as master and booster I'm sure there the same as a standard ss

 

[Skydrol]

I replaced the Brake Fluid on my G8/VE using nothing but hand vacuum pump. Took a good while but cycled a Litre of Brake Fluid using nothing but the bleed petcock and the vacuum hand pump.

That is how I purge the air bubbles from my brake lines. The only thing that you need to keep an eye on is the amount of fluid is left in the reservoir. If you let it go low air can be sucked right inside and you need to cycle the fluid to get rid of it. So what I did was, remove 4 oz, stop, add 4 oz and continue on.

Changed Front/Rear, Pads, Rotors, Brake Fluid and Front Wheel Bearings. A tedious 12 hour job.

So far after 1,000+ miles (1,609+ Km) have no dramas at all.

 

[brasher]

did it the old fashioned way too, no issues, brakes far exceed my expectations.

 

[Thumpin]

Hi Sanchez,

There's no difference with M/C between redline models. Same P/N.

I would suggest you have air hiding somewhere. Apart from the obvious which you appear to have covered, when you fitted the new calipers did you let fluid drain out allowing air back to the ABS unit?
If you did then this could be a problem that need a pressure unit to push out the air.

If you didn't do this, are you bleeding the brembo's from both bleed points for inner & outer pistons?

Do you bleed the outer first and then the inner. And then do it again.

If your bleeding fluid on your own by opening nipple and then pumping pedal , then closing the nipple... make sure your bleed tube has a loop in it the keep fluid from draining down allowing air back to the nipple before you close it off.

I've fitted a couple of sets of Brembo's and I always fill the caliper and hose prior to connecting the hose to the rigid pipe.

All I do is open the outer nipple on the caliper and then push fluid in via the hose end using a syringe. I keep going until all air has escaped and the unit is full of fluid. I then connect hose to pipe and bleed away on car. Saves heaps of time and fluid to get a nice hard pedal.

Keep muching around as results are worth it.

 

[SanchezCBR]

I don't think there is any air in the ABS. I took the car out yesterday arvo and the pedal feels ok. However I have bought the braided brake lines and will install them on Saturday.

I've been working on brakes a long time and know how to bleed the system well. I have a few different kits but I always do it with another person just to make sure.