Brake Bleeding

[tomallen_2003]

I have been playing around with the brakes a lot. I been using an eazi bleed system and now i have done it all and bled the brakes so that there is no air coming through. Done it 3 times. When i put my foot on the brakes though it is all spongy and can push the pedal all the way down. I was chatting to someone who thinks there is an air lock some where. Anybody got any other ideas?

[macdonald.dm]

Re: Brake Bleeding

Hi Tom.

As far as I know, if there is any air still trapped in your system it should have the effect of making the brakes 'spongy', but should NOT be the cause of the pedal being capable of being pushed to the floor (unless they are REALLY spongy!)

Does it feel like: spongy to the press, but pedal only travels, say, half way, but if you THEN keep pressure on the pedal, it gradually sinks to the floor? If so, I think this points to worn piston washers/bore in the master cylinder (presuming there's no actual leak).

[macdonald.dm]

Re: Brake Bleeding

Or, if you've rebuilt the master cylinder, piston washers fitted the wrong way around...

[tomallen_2003]

Re: Brake Bleeding

Hi donnie

It is spongy but all the way to the floor in one movement which is a bit strange. My master cylinder has 3 outputs one to the rear and then two to the front, the only other possible thing, which I very much doubt, is my master cylinder doesnt displace enough fluid as i have put bigger front brakes on it.

[dogoncrazy]

Re: Brake Bleeding

Tom
This is a real stab in the dark but how are you bleeding the brakes? - one at a time or other method.
With a Marina based dual circuit I seem to remember that you had to do Nearside front and the offside rear[only one bleed nipple at back] at the same time , then the offside front on its own. This was because of the way the circuits were split.
Some master cylinders split the circuits diagonally and others front and rear, so I would suggest that you follow the procedure as per the donor unless of course you are doing that already

[tomallen_2003]

Re: Brake Bleeding

Cheers alan. Mine is a bit of a bitsa but the all the brakes are triumph. The cylinder has one outlet to the rear which has a splitter then an individual outlet to each of the front calipers. I have been bleeding the two rear first then front nearside then front offside. The idea was to do the ones furthest from the cylinder first. I will try your idea of varying the sequence and also have a look in the book. Many thanks

[b_caswell]

Re: Brake Bleeding

Hi Tom, First try pumping the pedal then hold it down if it still creeps to the floor the master cyl is letting by.(on the little seal that is at the end of the piston.) Before rebleeding adjust the back brakes up tight to take out any slack in the wheel cyls. Another thing to check is that the pistons on the front calipers are working on both sides of each disc. If a piston is stuck the opposite one will push(bend) the disc away giving a spongy feel.
Try bleeding by pumping up the system and holding the pedal while a helper then opens the bleed nipple. Then close the nipple with the pedal down then repeat, Start with the closest wheel first then go round the car and do the closest wheel again last. Also make sure none of the brake hoses are bulging under pressure.

[lil_red_roadster]

Re: Brake Bleeding

...and its always worth making sure the caliper bleed nipples are at the top...i.e. above the fluid inlet...otherwise you can get exactly the symptoms you describe.