Thread: Brake bleeding problem..HELP!

Originally Posted by Dayne

I have just replaced the full brake linings and pistons on my 2.25ltr 109". I bled the rear brakes first. Good pedal.

Then the fun replaced the front pistons and pads and brake hoses. Now the pedal is soft and pressure goes quickly. When bleeding the front brakes, all the air was out. I think, I read their is a special way to bleed them. Could this be the problem?

The front brakes has a piston at the top and bottom of the shoes. The master cylinder has no booster. and worked fine before changing the brakes.

I have read that you should take off the backing plate and bleed it off the car to allow the air to get out. Laying it flat. (Seems like to much work, I would think it wouldn't be that hard.)

Any ideas.... Thanks

I understand there is a squence that the brakes should be bled. Do I understand you correctly when you said that you repaired the rear, then bled the system, then you repaired the fronts.

If this is the case then you may have introduced air into the rear again.

Might want to try a full bleed again, but follwing the sequence in which they should be done. Sorry I don't have that info - but I am sure somebody will have.

Originally Posted by Dayne

I have just replaced the full brake linings and pistons on my 2.25ltr 109". I bled the rear brakes first. Good pedal.

Then the fun replaced the front pistons and pads and brake hoses. Now the pedal is soft and pressure goes quickly. When bleeding the front brakes, all the air was out. I think, I read their is a special way to bleed them. Could this be the problem?

The front brakes has a piston at the top and bottom of the shoes. The master cylinder has no booster. and worked fine before changing the brakes.

I have read that you should take off the backing plate and bleed it off the car to allow the air to get out. Laying it flat. (Seems like to much work, I would think it wouldn't be that hard.)

Any ideas.... Thanks

A trick I learned years ago (current age 53 and reducing) grab a length of clear plastic hose just the right size to snug over the bleed nipple. drop tother end of into clear glass jar, bottle etc and bleed to buggery. If you think you have all the air out, bleed once more, brake fluid is much cheaper than a Panel Beaters bill.

Hope this helps.

regards shorty943.

1. Clamp off all hoses - this should give you rock solid pedal. If not bleed by loosening the union on the M/C, and if necessary the three way junction on the chassis.

2. release the back hose. Bleed the rear brakes, starting at the LH side. reclamp the hose to make sure there is no confusion.

3. release and bleed the LH front brake, starting with the lower cylinder. reclamp the hose to make sure there is no confusion.

4. release and bleed the RH front brake. release the other clamps, and adjust brakes, should now be OK.

Note:- If having problems bleeding the front cylinders in particular, remove the drums, back off the adjusters completely and clamp the shoes towards each other so as to completely push the pistons in. This minimises the volume of the cylinder and makes bleeding easier.

When bleeding, make sure that there is no possibility of getting air back in through the bleed screw. the way I have done this is to use a length of hose with a one way valve available from any auto shop for the purpose. A more elaborate setup is one that has it feeding into a container. One I have used has a sealed container with another hose out - you can apply a vacuum from an (scrupulously clean) oil syringe to bleed using suction.

As a last resort you can reverse bleed using a syringe to force fluid into the bleed nipple.

I might add I have never had to go beyond clamping back the shoes on my 109, and usually have no problems at all - the other methods though I have had to use bleeding the clutch on the 110!

John

yes, have to agree with JD, pushing the pistons right back in makes all the difference in the world, no where for the air to hide. this was the only way i could bleed the brakes in my first s11a 109 i had, worked 1st time!!

Originally Posted by Dayne

I have just replaced the full brake linings and pistons on my 2.25ltr 109". I bled the rear brakes first. Good pedal.

Then the fun replaced the front pistons and pads and brake hoses. Now the pedal is soft and pressure goes quickly. When bleeding the front brakes, all the air was out. I think, I read their is a special way to bleed them. Could this be the problem?

The front brakes has a piston at the top and bottom of the shoes. The master cylinder has no booster. and worked fine before changing the brakes.

I have read that you should take off the backing plate and bleed it off the car to allow the air to get out. Laying it flat. (Seems like to much work, I would think it wouldn't be that hard.)

Any ideas.... Thanks

Start bleeding at the furthest wheel cylinder from the Master Cylinder and work your way back to the closest, get someone to pump the brakes and hold pressure on the pedal while you crack open the bleed nipple (usually the passenger side rear wheel), the brake pedal will travel to the floor, hold it there till you tighten the bleed nipple, repeat until no air, just a steady flow of fluid appears, close nipple and move to next (should be drivers side rear wheel). Keep the Master Cylinder topped up, DO NOT let master Cylinder run dry or get too low, brake fluid washes off easily (detergent) easily, so dont worry about making a mess, if you follow JD's method use the Proper Clamps for clamping off brake hoses, normal locking or vice grips will damage old hoses, Regards Frank.

Agree with above. Do not be tempted to clamp hoses with vice grips or similar.

In desparation I have used 2 spoons (back to back) between vice grips to clamp hoses. Works nicely and doesn't destroy the hose.

Originally Posted by shorty943

A trick I learned years ago (current age 53 and reducing) grab a length of clear plastic hose just the right size to snug over the bleed nipple. drop tother end of into clear glass jar, bottle etc and bleed to buggery. If you think you have all the air out, bleed once more, brake fluid is much cheaper than a Panel Beaters bill.

Hope this helps.

regards shorty943.

As above but use 1 metre of tube and an old coffee jar with lid so that with the hose inserted into the lid you can place the jar on the top of the mudguard so that you can just open a nipple at a time and pump till you see all the bubbles escape and there is no need to pump, pump bleed.
I put a new m/cylinder in my rangie and had all 8 nipples fully bled in about 15 minutes on my own.

All of the above with one final trick.
Get someone to depress the brake pedal slowly as you do up the bleed screw. That eliminates the possibility of air getting past the threads.