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| V8 Ghia Mike |
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Yeah, another topic on the crappy E series brakes...
 I'm having issues with my car simply not wanting to pull up under hard braking. I don't think the brakes are even capable of activating the ABS! Car has ADB discs all round, not warped and easily within thickness limits. I recently rebuilt the front calipers, added new Bendix Ultimate pads and new front brake hoses, fluid and flush. The booster has vacuum (pedal drops when motor starts) and pedal height is OK. The problem is that I really have to stand on the pedal hard when emergency braking, worse in the wet. Just putting around in traffic they are average, but when I really need the brakes, it just seems that the car won't pull up hard enough. It seems like the brakes aren't getting enough line pressure when I hit the pedal. BTW, it was the same before I overhauled the fronts recently. I've even fitted a brace to the master cylinder to avoid firewall flex, if that even occurs in auto Falcons? Can the booster slowly degrade over time or when it develops a leak, it's all over? Cheers, Mike
_________________ EF Ghia 5.0 - XR8 in a tuxedo....classy, low and loud |
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| Benny D |
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sounds like u concentraded on the front brakes and done em up alrite. do u know if ur back brakes are even working?..lol
might be somthin to chek as they sorta help u stop too.
_________________ BA XT V8. Ice Mint. 18" Speedys. XR6T LSD. Full Pacemaker twin 2 1/2inch Stainless Steel system. Custom CAI. Black XR interior with white trimming. Powerbond underdrive kit 25%. |
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| V8 Ghia Mike |
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That is something I was thinking about, yeah!
 They have newish rotors and pads, but I might rebuild the calipers- pretty sure they are original at 395,000km!Mike
_________________ EF Ghia 5.0 - XR8 in a tuxedo....classy, low and loud |
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| arm79 |
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Did you check to see if the calpier slides are working OK. If not, then the pads wont be able to make full contact with the rotor.
And I wouldnt really worry about the back in the diagnosis. They don't do alot of the brake effort under heavy braking. Not saying to ignore them though. |
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| Johnson stroker |
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you can also look at upgrading the rubber lines to braided. removes HEAPS of flex. the rubber lines do flex quite a bit.
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| V8 Ghia Mike |
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I did grease the caliper slides when refitting everything, but maybe they have frozen up? I did notice that the inner pads were much more worn than the outers, does that mean anything?
In the wet they are a little scary. The first application of hard braking they don't do much until they bite. It's half a second of panic until I hit them really hard, but the braking distance is terrible. It doesn't seem as if enough pressure is being applied to the calipers. Master cylinder? Booster? Opinions? Mike
_________________ EF Ghia 5.0 - XR8 in a tuxedo....classy, low and loud |
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| arm79 |
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When you say you greased them, did you fully pull both inner slides out of the housing and make sure it moved back and forth properly?
The inners will always wear quicker than the outers because its the side that he force is being applied to. The outer is just being pulled into the disc. But then the difference in wear shouldnt be that great. My understanding is that if the master cylinder is leaking internally, the pedal will continue to sink to the floor slowly. Maybe there's even a small blockage in the lines somewhere? |
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| V8 Ghia Mike |
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Yes, all pulled apart, slides greased, new boots, the full monty. Maybe I should upgrade to slotted? The feeling in the wet is like pad knockoff, when that first push on the pedal doesn't do a lot. I know that I shouldn't have to push that hard to stop the car in emergency braking.
Also there is vacuum retained in the booster when I wobble the vac line plug. I'm thinking maybe the rear brakes aren't doing the job. I did grease the rear caliper slides a while back when changing pads and they were seized. Can a worn master cylinder reduce pressure to the calipers? It's not dropping fluid at all; a worn bore would allow fluid loss wouldn't it? Mike
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| arm79 |
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Was it always like this, or only since you did the work on the brakes.
I once helped a mate with brakes on his car and we pulled the boots off the slides. Test drive showed the brake needed alot of pressure on the first application... Second time you quickly hit the brakes they worked fine. If you let them release properly, you needed to put alot of pressure on. When we put them back on, we accidentally swapped the upper and lower inner boots. When we bolted the caliper back on one of the boots got pinched between the caliper and the spindle and stopped the caliper from sliding in properly. So when you took your foot off the brake, the pad would be pushed further away from the disc. One did this on one side, and it did affect the brakes alot. Maybe its something like this. And I wasn't referring to vacuum, but leakage internally. The test is to run the car (or even off will do) press the brake and hold for say 10 seconds. If the pedal stays firm, the m/c is fine. If the pedal continues to fall, then fluid is leaking past the internal pressure seals... And yes, this would reduce pressure to the calipers. Basically means the bore is worn or the seals are worn. It wont leak fluid externally, just loose pressure internally. |
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| V8 Ghia Mike |
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The car has been like this for years, so I thought I'd rebuild the fronts with new hoses to try and improve things. It didn't.
 The pedal seems to stay firm, but I'll admit it's fairly spongy. I did take care to not pinch the boots when bolting it all up and the calipers did slide smoothly. Yeah, I'm suspecting the master cylinder may be tired at 395,000km... Mike
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| WagonDad |
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Spongy generally means air in the lines, if you didnt replace the brake fluid it would be wise to, you only need 500ml of fluid and you can flush the whole system. I try and do a full flush at least once a year.
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