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Post by efiste2 on Nov 25, 2017 16:06:36 GMT 1
Looked at a potential purchase today, a 2010 1.6 Zetec-S Fiesta, it looks a good motor, but it failed its 2017 MOT on the following
Serious Leak on Shock Absorber
Brake Pedal has Insufficient Reserve Movement (3.3.A.5)
Its only after we came away an looked up its History we learned this, The shocks looked in good order in my DIY capacity but will be examining them in more detail if we return for a test drive etc etc, but the car has 12 months MOT so "in theory" the brake issue has been rectified to pass test.
Can the MOT experts explain to me what Reserve Movement is and what causes it, Basically so I can ask what work has been carried out, otherwise the car has good history and appears to be in great condition. And we have looked at a number of similar models and this is the best we have seen so far.
Thanks for any advice.
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Post by rhyds on Nov 25, 2017 17:58:11 GMT 1
I'm not an MOT tester, but I'd assume insufficient reserve movement means the brake pedal has gone "long" and has insufficient travel before it hits the floorboards. IIRC KarlB mentioned some of the newer fiestas suffered from long pedals and needed the ABS modulator bleeding?
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Post by valhalla on Nov 25, 2017 18:22:38 GMT 1
I'm not an MOT tester, but I'd assume insufficient reserve movement means the brake pedal has gone "long" and has insufficient travel before it hits the floorboards. IIRC KarlB mentioned some of the newer fiestas suffered from long pedals and needed the ABS modulator bleeding?This problem of sponginess in the brake pedal operation can afflict many cars that have little or no provision for ABS Modulator separate bleeding. With patience, the pedal will come back to a firm operation. It might be that the garage concerned has simply fixed the problem by "blocking" the brake pedal hard down overnight, then allowing the pedal to return naturally in the morning before retesting the car. There's nothing wrong with doing this, and I have had to resort to this on many occasions with different Landrover models that otherwise proved to be impossible to improve the brakes on. It seems to allow the trapped air to return back to the master cylinder reservoir, although I'm convinced that often as not it's just the seals around the master cylinder itself that are causing most issues. |
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remmington
Apprentice
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Post by remmington on Nov 25, 2017 22:17:30 GMT 1
I was waiting for someone to reply to this thread.
I would fail a car for "spongy brakes" or "too much travel on the handbrake lever".
But not what was quoted...
"Brake Pedal has Insufficient Reserve Movement (3.3.A.5)"
As Vahalla has stated, I too have had to "leave the pedal down over night".
A better interpretation of the fail is:
"no servo assistance" maybe?
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Post by Rhubarb on Nov 26, 2017 0:00:20 GMT 1
I was waiting for someone to reply to this thread. I would fail a car for "spongy brakes" or "too much travel on the handbrake lever". But not what was quoted... "Brake Pedal has Insufficient Reserve Movement (3.3.A.5)" As Vahalla has stated, I too have had to "leave the pedal down over night". A better interpretation of the fail is:
"no servo assistance" maybe?Nooo, cos that would be a solid pedal, or that's how I see it  |
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Post by upkeep on Nov 26, 2017 0:08:37 GMT 1
Why worry if it's fixed and has a shiny new MOT and if in doubt keep looking.
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Deleted
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Post by Deleted on Nov 26, 2017 0:18:03 GMT 1
I think that might of been incorrectly worded?
Brake Pedal has Insufficient Reserve Movement (3.3.A.5)
Does it not read;
Brake pedal has insufficient reserve travel ?
Basically this means that when the brake pedal is depressed that the working stroke of the pedal travels to the end, in other words the pedal pad touches the floor when it should not. Most brake pedals should at least in theory not allow the working stroke to move more than 25 mm, when the brakes are working correctly, without servo assistance!
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remmington
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Post by remmington on Nov 26, 2017 1:02:14 GMT 1
You can see now why....
I was cautious in answering this one!
My lack of understanding at what the fault actually is...? (or was...?).
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Post by valhalla on Nov 26, 2017 16:29:52 GMT 1
You can see now why.... I was cautious in answering this one! My lack of understanding at what the fault actually is...? (or was...?). I can now see the folly of my answer. Yes, you are both correct Hybrid/Remmington. We don't really know what the problem was, travel or movement. Totally different ends of the spectrum when you consider boosted vs. unboosted performance.
I have had a "problem" Discovery2 TD5 that came to me recently. It had been played-around with by a few garages, mostly in Yorkshire. Unboosted performance could only be measured by the pedal travel, which was OK. Servo-assistance performance was also OK, the pedal moved down under constant foot-loading. Pedal sinking was also OK, the pedal did not lose load for 10minutes of engine idling after the initial servo-assisted movement. However, this car had a long travel on the brake pedal, meaning that the pedal was only 15mm from touching the carpet under an emergency-braking action. It was only by comparing the car against my experience with other D2's that I knew something was very wrong.
A poor bleeding procedure in Yorkshire had resulted in a problem at the ABS Modulator. Using the correct diagnostic interface procedures allowed me to fully bleed new fluid through the whole system, and shift whatever air had been pushed back to the ABS unit, by driving the modulator valve on each corner of the car.
Even then, I had to block the pedal overnight to get the last 25% of improvement back on the boosted travel of the pedal, resulting in a reserve of 60+mm when it was fully depressed. The issue was compounded by the fact that no objective data exists in Landrover documentation, to say what the "factory" fresh deflections should be for given loads on the pedal. It's only from subjective experience that I had to agree with my customer on this car, the pedal was halting too close to the floor.
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Post by Karl on Nov 26, 2017 19:54:24 GMT 1
Common on this age of fiesta 2008-2010 generally. ABS service bleed would normally sort them out.
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Post by Karl on Nov 26, 2017 20:00:22 GMT 1
And often you would find the customer unaware of the long travel.
Guess you could fail one but it would have to be near on the floor which I've never seen
Same goes for shock absorbers have to be pissing out fluid not just a misting of oil. You generally find if they have been like it for some time. And all the fluid leaks out . Then it is an pass . As bounce/efficiency check is no longer part of the test
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Post by efiste2 on Nov 26, 2017 20:28:51 GMT 1
Dealer straight away said yes its had a fluid change and the ABS pump was "bled" using the diagnostic machine etc etc, and the car drives and stops well, including the pedal being progressive. So we took the plunge and bought it. Thanks again Chaps!!!
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Post by efiste2 on Nov 26, 2017 20:32:46 GMT 1
Can I ask if bleeding the ABS Pump is simply a case of connecting it to the diagnostic and pressing the pedal when advised by the Terminal, or do the bleed nipples still need to be open/closed manually at the caliper/cylinders etc etc. This could actually cure the same issue with my Parents 59 plate Fiesta...
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Deleted
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Post by Deleted on Nov 26, 2017 20:53:43 GMT 1
When priming (bleeding) brakes whether electronically or otherwise, each road wheel should have the bleed nipple loosened to expel air in the recommended procedure of the OEM manufacturer.
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Post by Karl on Nov 26, 2017 22:00:42 GMT 1
Can I ask if bleeding the ABS Pump is simply a case of connecting it to the diagnostic and pressing the pedal when advised by the Terminal, or do the bleed nipples still need to be open/closed manually at the caliper/cylinders etc etc. This could actually cure the same issue with my Parents 59 plate Fiesta... You open both the front bleed nipples together, whilst connecting an conventional pressure bleeder. IDS then runs the ABS module in an process. Pedal isn't pressed Goes in an sequence Then does the rears the same way |
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