Having problems bleeding brakes

[R1 Indy]

Basically I'm trying to bleed the brakes on my kit car. it has a basic non assisted master cylinder, and uses ford sierra callipers.

Ive bleed all four corners the 2 person method, including turning the rear callipers upside down, so that the nipple is at the top.

Im now not getting any more air out.

But the pedal is still spongy, infact i can hit the stopper at the end of the master cylinder!


But the strange thing is, if i put the hand brake on, i get a lovely hard pedal feel, but when i take the hand brake off again, its all spongy again.

Ive tried lifting the hand brake on and off while bleeding, but no success.

Does anyone have any good ideas?

Cheers

[geeks]

R1 Indy said:

Basically I'm trying to bleed the brakes on my kit car. it has a basic non assisted master cylinder, and uses ford sierra callipers.

Ive bleed all four corners the 2 person method, including turning the rear callipers upside down, so that the nipple is at the top.

Im now not getting any more air out.

But the pedal is still spongy, infact i can hit the stopper at the end of the master cylinder!


But the strange thing is, if i put the hand brake on, i get a lovely hard pedal feel, but when i take the hand brake off again, its all spongy again.

Ive tried lifting the hand brake on and off while bleeding, but no success.

Does anyone have any good ideas?

Cheers

Had this once and had air in the master cylinder, are there nipples you can use to bleed that?

[chongwong]

NIPPLES

[shiftydave]

chongwong said:

NIPPLES

Glad it's not just me laughing!

[Nick M]

Are they the Sierra calipers that you wind in to change the pads ?

And if so, do the pistons just need to be pumped back out and you've just not quite got there yet ?

Also, I found the best way to bleed brakes on several cars, including my Westfield with 4 pot front calipers and Sierra rears, was using one of the pressure bleed systems, but with using a tyre which had a low (around 15psi) pressure rather than 30+psi.

[Agrispeed]

Nick M said:

Are they the Sierra calipers that you wind in to change the pads ?

And if so, do the pistons just need to be pumped back out and you've just not quite got there yet ?

Also, I found the best way to bleed brakes on several cars, including my Westfield with 4 pot front calipers and Sierra rears, was using one of the pressure bleed systems, but with using a tyre which had a low (around 15psi) pressure rather than 30+psi.

Yes a very handy bit of kit - called a Gunsons Ezi-Bleed IIRC, makes it a easy one man job

[R1 Indy]

I was using an eezibleed tostartwith, but wasn't having a lot of luck with it!

I still don't understand why I'm getting good feel with the h/b on, but not with it off?

[Nick M]

See comment above about the possibility of the rear pistons needing to wind back out - with the handbrake on you're stopping the pads and pistons from moving which gives the solid pedal.

[spaximus]

what you need to do is disconnect the handbrake cable and remove the rear pads. Using the correct tool wind the piston adjuster back in as far as it will go. Then using two g clamps hold the piston in and bleed the brakes as before. Re fit the pads and locate the caliper, then pump the brake pedal a few times and the calipers will self adjust. Refit the handbrake caliper and adjust it works every time. Sierra calipers are prone to the adjuster being wound out slightly then air gets trapped. Doing it this way all air is forced out.

[R1 Indy]

Thanks, i will give that a go.

[SS2.]

FWIW, I needed to bleed the brakes on the Tiv a couple of weeks ago but was on my lonesome - went to my local Factors and purchased one of these.

OK, so it's only a plastic bottle, a rubber tube and a non-return valve (for about £7.50), but it certainly made it a simple one man operation..

[R1 Indy]

Well I've just given this a go, but im not getting any fluid coming through, but i am getting a little "psss" every time the nipple is opened.

Is this a sign of a lot of air in the system?

I think i need to find my ezzibleeder, as my feet and legs have had enough of pumping!

[R1 Indy]

Ive found the eezibleeder, wish i hadn't though, the thing just exploded, spraying half a bottle of brake fluid over me and the mothers drive!! I was only using about 20 psi though.

Although i seem to have got a fair bit more air out, so will put back together and have ago.

[Nick M]

Possibly a bit late, but I always used some PTFE tape around the various threads of the bottle and the master cylinder resevoir to avoid, or at least minimise, leaks.

Also, try a bit less pressure - you don't need oodles of pressure, just enough to push the fluid through the system.

Don't forget to keep checking the levels in the bottle and resevoir to avoid reintroducing any air.

[balls-out]

It sounds like you have removed the air from the system - so I don't think clever one-man bleeding tools is the answer.
The 'pump up' you are are getting is taking up some form of slack in the rear. So the handbrake is taking that slack up giving you the firm pedal. I'm not familiar with sierra calipers, but could be the piston is returning into the caliper and needs some adjustment.
If the pad are new on scored discs it could even be that the pad need to bed in.

have you just build the car? It could even be that the caliper isn't firmly fixed and slack you are getting is moving the actual caliper itself. Possible get somebody to pull the handbrake while you watch the rear calipers. If all is well you should see very little movement when you apply the handbrake, as the pads should already be lightly touching the disc.

[R1 Indy]

Yes i have just built the car, so the pads etc are not bed in yet. the car is now all back together and on the ground, and must say it is 10x better now, if i try really hard, i can just about get the master cylinder piston to hit the stopper, but the wheel seems to lock before then anyway.

Hopefully the IVA examiner will now be happy, he actually failed it because he thought the pedal was hitting the bulkhead - with no free play, when it was actually the master cylinder bottoming out!

But i really can't see there being anymore air in the system.

[Nick M]

What front calipers are you using ? And what master cylinder ?

If it's 4 pots then you can end up with a very long pedal travel because of the volume of brake fluid being moved.

I swapped to the Caterham AP master cylinder on my Westfield when I was using Wilwood and Outlaw calipers - made a massive difference to pedal travel.

[Gafferjim]

Also have you got the front callipers on the right way up? with the sierra ones it's easy to fit them on the wrong side with the nipples pointing down, they need to be fitted with the nipples at the top.

[Captain Cadillac]

Did you bench bleed the master cylinder before installing it?

[Mave]

Why have you got the rear bleed nipples at the bottom? Is there something about the design which stops you mounting them the right way up?