Struggling To Bleed Brakes

[Guest James24785]

Need a little bit of advice please folks.

Over the past few weeks I've had the braking system completely drained as I've had suspension etc removed. I've not touched the rear calipers, only removed the fronts.

I've come to bleed up the system now with fresh fluid and I cannot get a peddle at all.

 

I'm using the gunson easy bleed and I've stuck a litre of fluid through it.

Fluid flows from the nipples seemingly air free, but it takes a few pumps of the peddle to stop the peddle just going straight to the floor.

Few seconds later and the pedal will go back to the floor with little resistance.

 

Bleed nipples are all at the tops of the calipers. The only thing I can think of is, the rear brake lines loop up and down into the caliper, meaning that the top of this loop is above the bleed nipples. Could air be trapped here?

I've read on a couple of blogs that the rear calipers need to be removed in order to get the bleed nipples higher and for the air to escape.

Is this the case? Sorry for the long post, but any help is appreciated

[tractor]

on mine because rear nipples are at the bottom i have i have to remove rear calippers and turn them so nipple is at the top and balance so that it is on the disc so i can bleed it the normal pedal pump method then once bled refit its a ball ache but works

[tractor]

just having the fronts off i would still bleed hole system

[cb750]

Try doing it the old fashioned way if you've got a helper.

[Guest James24785]

just having the fronts off i would still bleed hole system

Yeah I'm doing the whole system mate, as I wanted to put fresh fluid in anyway

[tractor]

or take calippers off and get a spacer a couple of mm bigger than disc to fit between pads and then pump brake but still bleed nipple needs to be at the top this might be an easier way depending on the lenght of your flexi brake pipe

Edited May 2, 2018 by tractor

[Guest James24785]

or take calippers off and get a spacer a couple of mm bigger than disc to fit between pads and then pump brake but still bleed nipple needs to be at the top

Yeah I think that's next thing to try

[magh]

I used the Gunson easy bleed system on mine that uses the spare tyre to pressure it which worked a treat forgetting fluid through. But to provide a good firm pedal it needed the good old fashioned 2 man approach shouting open, down, close, up lol

[Guest James24785]

Looks like I'm going old school lol

[brumster]

The problem with solely using the easibleed is it doesn't move the pistons at either the master or slave end, and I suspect some master cylinders (with two outlets) probably trap air in the piston? Maybe? A mix of easi-bleed, then a bit of manual pumping/tube-in-pot, would probably work better (assuming there's nothing wrong with the system anywhere of course)....?

Edited May 2, 2018 by brumster

[Guest James24785]

There hopefully shouldn't be anything wrong with it, as it was fine beforehand. All I've done is removed the front two calipers and emptied the lines

[Bob Tucker]

Ive helped on a couple of Hoods that had this problem.

In both cases the brake pipes were fitted along the top of the tunnel, ie higher than the calipers.

Both were solved by putting the rear of the car on high axle stands, then using an easy bleed

as well as manual pumping. Its a bit of a faff, but you wont be doing it every week.

[Guest James24785]

Think you're onto something there, Bob. The brake lines run exactly where you say! I'll lift the rear and give it another go tonight

[cb750]

I must be lucky with my car (it's not a superspec though). My pipework runs inside the top side rail of the monocoque body so it's well above all 4 calipers and I've never had trouble bleeding the brakes. I probably will now I've said that!