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Anon
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MOT failure - Parking Brake Efficiency

I've sorted the other 7 items on the failure list, bit of welding on the front step and back panel as i've not got a tow bar so it falls in the critical zone.

The only thing i'm not sure about is the failure on parking brake efficiency. It doesn't give the efficiency % on the sheet, but having driven down the road and applied the brake, it certainly isn't doing much. I did several speed ups and slow down on the handbrake to clean it all up as I suspect it's just corrosion through lack of use, and re-adjusted the rear shoes, and it feels a bit better, but I certainly can't get the rear wheels to lock when I drive along and pull up the hand brake (never have been able to). What's everyone else's vans like for this? If i'm going 30 and only rely on the hand brake to stop, it takes a good long distance, I guess 50m, to fully stop. I know the shoes are fine as the van passed on all other brake related tests for the MOT.

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Sun 23 Aug 2015 @ 19:33 Edit this messageQuote this messagePMQuote this message
Anon
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Hi Middld,

The hand brake should give 25% of your braking to the rear wheels, most of your braking power will be at your front wheels of over 70%.

doujoy

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Sun 23 Aug 2015 @ 20:44 Edit this messageQuote this messagePMQuote this message
Anon
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Doug, I read that on the MOT regulations, but what does 25% mean in real life on a CF without access to a testing machine?

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Sun 23 Aug 2015 @ 20:53 Edit this messageQuote this messagePMQuote this message
Anon
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parking brake

Hi Dave,if you adjust the rear brakes so the wheel will not turn by the 4th or 5th click on the hand brake lever I should be right for the mot.Cheers Jim.

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Sun 23 Aug 2015 @ 21:20 Edit this messageQuote this messagePMQuote this message
Anon
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parking brake

Hi Dave,you should not be able to lock the rear wheels with the hand brake while moving.The brake should lock the wheels while standing.If you can't acheive this you will have to strip and clean the whole sestem inclouding the h/brake cables,don't forget to lub the cables.Cheers Jim.

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Sun 23 Aug 2015 @ 21:45 Edit this messageQuote this messagePMQuote this message
Anon
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Hi Middld,

The twenty five per-cent is a resistance reading on a brake test roller bed, most reading are higher around 28-30.
But the even black rubber skid marks should be a good indication of a high resistance.

doujoy

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Mon 24 Aug 2015 @ 11:17 Edit this messageQuote this messagePMQuote this message
Anon
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So doug, your rear brakes will lock up with just the hand brake applied as you're driving along (to make the skid marks)? what's everyone else's experiences of trying to hand brake (turn) their CF? I know mine is no-where near locking up, and like I said I pass the other MOT braking tests OK, so implies my shoes and drums on the rear are OK....

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Mon 24 Aug 2015 @ 13:44 Edit this messageQuote this messagePMQuote this message
Anon
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Hi,

Yours looks like a fairly light weight camper and if your brakes are working as they should be there is no reason why you could not test the handbrake in this way as a guide to how well they are working.
What ever you think of this method at the moment the MOT station is not going to accept the readings they are getting!

doujoy

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Mon 24 Aug 2015 @ 16:03 Edit this messageQuote this messagePMQuote this message
Anon
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So I took the van back for a re-test and the brakes are still no good. The braking force measurements when using the foot brake are 300kg per side which the tester said was exceptionally good. But the handbrake, operating the same shoes, gave only 90 drivers and 60 passenger side. He suggested that I wind off the hand brake adjuster, re-adjust the shoes, then wind back the hand brake adjuster. I found that there must have been something wrong with the adjustment. When I wound off the hand brake, it allowed loads more adjustment of the shoes (I could screw the adjusters in much further), so then the hand brake is now much further down the adjuster bar. I've looked at the exploded view in the Haynes, but can't work out exactly what's happening. Does winding the hand brake in before adjusting the shoes cause it all to go wrong... I hope so if that solves the problem. I'm hoping it causes the pivot point to be wrong so you're getting edge rather than whole shoe contact maybe? Driving the van and yanking up the hand brake doesn't seem to feel any different though.... Any advice? need to fix it tonight to get back in for a test tomorrow.

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Wed 26 Aug 2015 @ 19:09 Edit this messageQuote this messagePMQuote this message
Anon
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Lack of rear brakes

Hi,from what you say it seems to me that the cables need freeing and lubing then let it all off and the adjusting start again.Cheers Jim.

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Wed 26 Aug 2015 @ 21:12 Edit this messageQuote this messagePMQuote this message
Anon
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Hi,

You should set the adjustment so that with the footbrake off you can just turn the drum but feel the high spot on the shoes, once that is set then adjust up the handbrake to lock the wheels against hand turning when jacked clear of the ground.
At that point you should have handbrake holding on about three or four clicks of the handbrake lever, none this will work well unless the cables are not seized or the brake shoes are stuck with rust on the back plates or levers inside the brake drum seized.
The footbrake readings suggest the shoes are carrying enough lining so it comes down to handbrake moving parts being restricted in some way.

doujoy

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Thu 27 Aug 2015 @ 10:28 Edit this messageQuote this messagePMQuote this message
Anon
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Cracked it. MOT passed. It was the issue of setting the brake adjusters without first backing off the handbrake cable completely. Doing this causes the normal brakes to be OK, and the handbrake feels OK, but due to the way the lever in the drum pivots, you only get an edge contact between the rear shoe and the drum rather than the full face contact. That's that solved....!

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Thu 27 Aug 2015 @ 16:36 Edit this messageQuote this messagePMQuote this message
Anon
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hand brake

Hi Dave,very pleased that you finally sorted it out.I hope you will now enjoy the van.Cheers+Beers Jim.

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Fri 28 Aug 2015 @ 21:12 Edit this messageQuote this messagePMQuote this message
Anon
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Thanks Jim and Doug, good to learn something new each job you come across!

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Fri 28 Aug 2015 @ 21:19 Edit this messageQuote this messagePMQuote this message
Anon
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Hi,

We all need help somewhere along the line, that is the point of clubs like this, glad your through that test for another year.

doujoy

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Sat 29 Aug 2015 @ 08:53 Edit this messageQuote this messagePMQuote this message
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