Brake bleeding - air lock?

[RussG]

Hi,
I’ve fitted ZRX1100 brakes to my project so the whole set up is new, its filled with fluid, no air being pumped through but the lever still goes back to the handle bar. Thinking I must have an airlock? Does anyone have any suggestions as to how I might progress? I’ve used an Easybleed so far with the capture pot placed above the calipers.

Thanks Russ

[warren3200gt]

Have you got a bleed nipple by the lever to bleed the reservoir to mc?

[RussG]

No, I don’t

[RussG]

To “mc”?

[warren3200gt]

Master cylinder

[marmck]

Pump lever until you get a firm pull , don't let it go tie wrap in this position turn bars so master cylinder is level & take top off ,place clean rag on top for safety. Leave for 4 or 5 hours ,loosely put master cylinder top back on & remove tie wrap ,then repeat process & leave overnight

[BAFF1960]

Hi.
Back bleed with a syringe from the caplipers alternating between sides. This is a trick used in a/c maintenance. They have long torturous routing and it always works.

[deka]

Hi.
Back bleed with a syringe from the caplipers alternating between sides. This is a trick used in a/c maintenance. They have long torturous routing and it always works.

Second that, you still need to build pressure up with a few pulls on the leaver but backfilling is the best way to go and ensures yhou push the air in the direction it really wants to travel

[Philippe]

Hi RussG

are you using the original brake line distributor where the stoplamp contact is screwed in?
If so, unscrew the two bolts with which it's attached to the lower yoke and turn it so that the air, perhaps trapped inside, can escape towards the master cylinder.
An other cause might be that the tiny small hole in the master cylinder is closed, it doesn't take much to constipate it; use a 0,3 mm drill to get it free. If it's constipated and you free it, you'll see a lot of air bubbles coming out of the small hole as well from out of the "bigger" hole in the master cylinder.
Good luck with it!
GrtZ
Philippe

[RussG]

Thanks guys, lots of good advice, I’ll let you know how I get on, poorly Mum sitting this weekend though…

[RussG]

So, did it all and still no change. When I back bleed it fills the reservoir, did with the lever on and out. When I bleed normally I just get fluid, checked the hole and they’re clear. Really scratching my head now
Tried to add pics but can’t work it out. Any more ideas what could be wrong? All components are new btw

[floydsz1]

Presumably the mastercylinder is the correct bore size for the calipers

[compo z1r]

if u deffo have no air in system and no pressure the fluid is over riding the seals if u have rebuilt check seals are put in correct way if not get a rebuild kit and start again about it really

[RussG]

How do you tell if the master cylinder is the correct size? I’ve never seen them advertised by size …

[compo z1r]

How do you tell if the master cylinder is the correct size? I’ve never seen them advertised by size …

never had a rex but looks like standard 5/8ths