having some trouble here

a while ago i replaced my rear calipers because the previous owner had replaced the master cyclinder but snapped the two bleed nipples on the rear calipers. which is why i got it so cheap.

i let the fluid all drain out the system inbetween swapping the rear calipers. ive bled the system 4 times now (2man method). on the last time i got one tiny measly bubble out the rear right.

the brakes are miles better but still spongy. but im not loosing any fluid so i dont think its a leak.

whats the test procedure for brake fault finding? ive seen this guide on the honda forum and am checking if it applies to the gti?

BRAKE BOOSTER INSPECTION

Functional test:
1. With the engine stopped, Depress the brake pedal several times, then depress the pedal hard and hold that pressure for 15 seconds. If the pedal sinks, the master cylinder, brake line or a brake caliper is faulty
2. Start the engine with the pedal depressed. If the pedal sinks slightly, the vacuum booster is working. If the pedal height does not vary, the booster or the check valve is faulty

Leak Test:
1. Depress the brake pedal with the engine running then stop the engine. If the pedal height does not vary while depressed for 30 seconds, the vacuum booster is OK. If the pedal rises, the booster is faulty
2. With the engine stopped, depress the brake pedal several times using normal pressure. When the pedal is first depressed, it should be low. On consecutive applications, the pedal height should gradually rise. If the pedal position does not vary, check the booster check valve.

Check valve test:
1. Disconnect the brake booster vacuum hose at the booster.
2. Start the engine and let it idle. There should be a vacuum available. If no vacuum is available, the check valve is not working correctly. Replace the check valve and retest.

END TEST

and if that fails to come up with anything will it just be old expanding rubber brake lines? will this be a visable expansion?

thanks in advance for your help

jim

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the world is changed by people in sheds

try clamping the flexi hoses just after where they join to the metal pipe, if you instantly get a hard peddle then youve found the problem.
clamp both rears at same time then one by one to find the suspect.
also repeated pumping of the pedal can sometimes cause a seal in the master cylinder to deform which will also give a spongy pedal

The fact that you let it run dry when changing the calipers probably means the ABS pump has got air in it, and they are VERY difficult to bleed if they have been left to run dry.

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"Supercharged - 454.1bhp/317.5lb/ft"
Peugeot 306 GTi-6
2000 (X), Moonstone

my drive slopes downwards. so i place my car facing down it with the front on ramps. this luckily ends up with the car being bang on level when im working on it.

and yes i have let the abs bleed dry.

whats the procedure to bleed the abs? can you link me if theres an FAQ please

cheers

jim

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the world is changed by people in sheds

Can he not activate the abs pump by shorting a pin/plug or putting a live to it?
I left mine totally drained ages and never had an issue bleeding it after.

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andrew315rawson@live.co.uk
Moonstone phase 7 gti6
My Project thread: http://www.306gti6.com/forum/showthread.php?id=119992&page=1

lovely, this may seem a silly question then but will an official pug garage still have the electric gizmos to open these valves?

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the world is changed by people in sheds

Yes, they should be able to do it just fine.

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"Supercharged - 454.1bhp/317.5lb/ft"
Peugeot 306 GTi-6
2000 (X), Moonstone

that's all I have ever done, other than on load comensator equipped vehicles ensured the valve was positioned as if the rear was loaded (i.e hold the valve open) never had to touch the ABS system in any way when bleeding.

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need a part number? get on here - http://public.servicebox.peugeot.com

Bring on the Trumpets.

this is guaranteed to be air in the ABS. I've had it numerous times, though not much on the Peugeot. I was bleeding it and bleeding it and getting nothing but fresh fluid. VAG's let you cycle the ABS as Niall suggests, though I wasn't aware PP did.

When you let the system run dry, as I have done before, you get air trapped in the ABS loop. You will prove this if a double-pump of the pedal results in a significant change in feedback pressure.

The surefire cure is to drive to a gravel car park, mash the brakes numerous times to make the ABS cycle 40-50 times, then drive around for a bit (20 miles or so, braking often). Drive home, and you'll find an air bubble at a bleed nipple - possibly even just one bubble. When I had this with my ex's Rover coupe I must have bled it 15 times all around and was at the end of my tether. After employing this method, I got an air bubble about an inch long at one rear nipple - then the brakes were perfect.

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I'm Si btw

Night Blue VW Golf GTD
Bianca LBSC Rallye - Track/Road Slag Project Thread
Sparkling Silver Mini Cooper D - Super Dooper - (The other half's wheels)

it is yes but I was wondering if theyre spongy because of the new pads you've fitted that need bedding in?

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andrew315rawson@live.co.uk
Moonstone phase 7 gti6
My Project thread: http://www.306gti6.com/forum/showthread.php?id=119992&page=1