Help dam brake light on after caliper change

[hightower]

Further to my questions about seized brake caliper pistons last week i ended up getting some new calipers and pads, i fitted them last night and bled the front brakes and have just been out to test it tonight and a few things have cropped up

1. pedal traveled alot further than before or expected but this could be due to how bad the old calipers were as the pads were basically binding on the discs, so now its got proper working calipers that release the pads it could mean it needs more fluid/pedal travel before the pads engage. it could also mean there is still air in the system as i trusted the pedal operation to my other half while i did the bleed screws etc and she said the pedal was nice and firm once we had done both sides. the brakes now bring the van to a standstill and i know you have to bed the new pads in but didnt brake as good as i expected (maybe expecting too much from a 24yr old braking system)

2. now the brake warning light is on all the time which it didnt do before.

Do i need to bleed the rear brakes too?( i didnt let the fluid level drop below min when i changed the calipers)

Any other idea's as we are supposed to be going away friday morning.

[DentedDevon]

If you loose pressure in one of the brake circuits it triggers the warning light.
This can happen while bleeding the brakes. Did to me any way.
To reset it I removed the switch from the master cylinder (its located about half way along it ) and refitted it again.
As for bleeding the brakes, I highly recommend Gunsons easy bleed kit. It is well worth the money - Ive used it on several vehicles and I'm no longer worried about disconnecting bits of the clutch or braking system .
New flexible hoses will improve the pedal feel + they are not too expensive. Check the rear brake cylinders , they have always needed replacing on vans Ive had.

[hightower]

Thanks Richard,

I think the flexible brake lines were replaced last year for the MOT.

Are the back brakes easy to bleed? if so i will have a go tomorrow night and redo the fronts again and see if it improves the pedal feel.

I tested it on a straight road in a industrial estate from about 40mph and it brought the van to a stop ok just alot more pedal travel than expected, trouble is i don't know how good brakes should feel on these vans due to the knackered calipers and binding brakes the van has had since we got it.

the system obviously lost its pressure when i replaced the calipers so that could be why the light is on, i don't think its the master cylinder seal gone as i had that happen on my old pug 309 gti and that was pedal to the floor and NO brakes when that went.

Is the light switch easy to take out and reset on the master cylinder ?

Thanks in advance

[AngeloEvs]

The brake fluid level switch is on the top of the resevoir and this connects to the brake warning light along with the handbrake (except it lights up much brighter if the fluid level falls). You will see it as soon as you pull the cowling off. Their is also a fluid pressure switch on the resevoir.

[Red Westie]

The brake warning light works off two things....the hand brake switch and the resevoir fluid level switch (as far as I am aware nothing to do with pressure! sorry mate..)
Excessive foot brake travel after caliper change is likely just air in the system.
Yes bleed them all (rear brake cylinders as well as front calipers) working your way from the furthest to the master cylinder to the closest.
Sometimes....if you are unlucky....FULL STROKE PEDAL bleeding on a warn master cylinder can damage the seals (hopefully this isn't the case here)
Be careful not to overwork your brakes on new pads, they can overheat due to the fact that they are not fully contacting the discs until properly bedded in (admittedly more of a problem with new pads on worn discs)
METHOD:
Open nipple....push and hold pedal down at the bottom of it's stroke....tighten nipple, allow pedal up.....when up open nipple again....press pedal down...so on so forth, locking off (closing) the nipple each time the pedal is down. Make sure you use a clear pipe and it remains submeged in fluid so air does not reverse flow back into the caliper/cylinder. Bleed until fluid runs clear and with no bubbles. Lock off nipple when pedal is held down. Nice slow pedal strokes both up and down..say 2 seconds to press or release full stroke of pedal.
DOT4...
PS unless you were taking about the brake light itself? in which case it could be a faulty switch.
Martin

[ermie571]

Hi - I have just had the brakes done on both my vans. Front pads and rear shoes on one, and pads, shoes and drums on t'other.

I expected it to stop better....but for a while it was the same....and gradually improved as the pads bedded in to the shape of the discs. After 100 miles I took both back to have the handbrake adjusted after the shoes had worn in. Pedal travel on both is from top to pretty much bottom for hard braking, but gently braking, and you can start to feel pressure about 1/3 of the way down.

Hope this helps

Em
x

[DentedDevon]

I believe all T25's have dual circuit brakes ,split front and rear.
Not all have the brake failure warning switch, which operates if pressure is lost in one circuit.
The fluid level switch is on top of the resevoir.
IIRC the brake failure switch is on the side of the cylinder between the conection for the front circuit and the rear circuit.
Im wrong about removing it to reset it , just need to disconnect the battery or disconnect plug on the back of the warning light.

[PEET]

Bleed all 4 brakes startin with the nearside rear first, the off side rear, nearside front and offside front last (assuming it's right hand drive). Ensure the fluid is up to the max mark before you bleed each brake and ensure the rear brakes are fully agjusted up to... have fun!!

[hightower]

Thanks for the advice chaps. I re-bled the whole system, back to front (had some air bubbles from the rear but not much, got quite a bit from ofside front though), pedal feel and pedal travel are much better, alsmost the same as before, it brakes well all ready even after only 10 miles or so. However the brake warning light is still on (on dash) , maybe it will reset itself on our trip to Newquay tomorrow.

All the brakes seem to be engaging on each wheel when i tested them, so i guess both circuits are working.

My fluid resevoir does not have a level indicator on it either so its not that.

I couldnt believe how much easier it was to push the van along the driveway (so i could get in the garage), 1 hand rather than full on worlds strongest man attempt. It also accelerated much quicker, so i am looking forward to the increased mpg i will hopefully be getting being bind free.

[getunder]

I had long brake pedal travel after reassembly of new brake pipes and couldn't get much fluid out of the bleed nipple which I blamed on heating it to remove it. Turned out that you can't bleed the system if the van is jacked up very high due to the front/rear brake compensation valve restricting the supply. Probably not your problem but worth knowing about.

[AngeloEvs]

Just in cae it' s still a problem, the Haynes manual shows the handbrake switch (and warning light)as hydraulically operated.

[DentedDevon]

Have you managed to get the warning light light off yet ?

[Miss Marple]

I've just had my camper's back wheel bearing changed and it came back with the brake warning light on. Unplugged it from behind the switch as mentioned above 'et voila!' sorted. This forum is fantasic!