20 replies to this topic

[cal844]

To aid bleeding I usually slightly over adjust the rear brakes so they are constantly dragging. Then you might need to bleed each union individually along each pipe to chase the air out

[imack]

Clamp all four flexi hoses at the same time and the pedal should be rock hard.
Don't do this if you're using braided hoses though.
If the pedals high and hard you're problems at one or more of the cylinders or calipers, if pedal is still poor problems at master cylinder, limit valve or air in the pipes between the two.
Gravity bleeding always works well for me.

[grahama]

Will try that this weekend. Can you explain gravity bleeding please, been mentioned a couple of times but can’t see it forcing air out !!

Have googled gravity bleeding, need some tubing lol.

Thanks

Edited by grahama, 12 October 2018 - 10:29 AM.

[expat_cat]

I changed to using Eezi-bleed as the older methods also have their shortcomings.  I would expect eezi-bleed to have worked for you, but some questions if I may:

 

When you bled the brakes, you said you got air out.  Do you get air out when you do another session (i.e. after you have tried the brakes)?  If you do get more bubbles, is that immediately, or after a fair bit of fluid has passed?

Do you get Air bubbles at more than one brake?

 

Asking the above to try to determine if the problem is at the "top" of the system or maybe at the caliper or wheel cylinder.

 

You mention a rebuilt MS.  Did you do that?  Don't mean to be picky, but could you have got any seals the wrong way round?  Was the MS bore really nice and clean?

[maccers]

I've installed a few sets of single piston Cooper S calipers on 2 of my cars and one set on a mates. The thing I found really helped was to remove the brake pads and insert the same size plywood of a lesser thickness, probably half the thickness of a new pad. This should allow the pistons to pop out, you'll see this, so you know the actual pistons are working. I dont know the exact technical reason behind why I works, assume by doing this as much of the caliper body is flooded with fluid to drive out any air bubbles. 

 

I have used a one way valve before, in the absence of any one else to help me, and used the pedal pump method. For existing "wet" systems where I am just replacing the fluid every other year the pressurized Ezi Bleed works fine. 

 

Gravity bleeding, not sure if this is the same as "venturi" bleeding where you leave the nipple open and let the fluid bleed out naturally. This has only every worked on an old Yamaha YZF1000R where the brake master is directly above the caliper so has maximum gravity assistance.

 

Good luck! 

[grahama]

Hi all,

 

Still got a pedal after leaving it for three days pressurised so no leaks I feel.  I have also gravity bled the lines this time and no air coming out at all.

 

I now have to put immense pressure on the pedal to get neat the pedal stop which must be a good thing.  I do feel that the pedal is lower than I wanted, but its does seem to be working.  (the car wont move when pressed lol). 

 

What I'm going to have to do is keep an eye on it and re bleed occasionally to see if any air has moved if trapped.

 

Many thanks for all the input, 

 

Graham