Bleeding the Brakes

There's nothing worse than having a pedal that just drops to the floor when your trying to stop. The usual cause aside from a dodgy master cylinder or leaking brake pipe is trapped air.

To remove this air you must bleed the lines.....

How does one do this? Well there are bleed nipples on the calipers and in rear drums the wheel cylinders.

The bleed nipples are loosened with an 8mm spanner.

Here's a picture of the front bleed nipple.....



And the rear.....



There are 2 ways to do this, the 2-man method or pop to Halfords and buy an Easibleed Kit. Also a litre of DOT 4 should be enough to fully renew the fluid and have a wee bit spare.

The 1-Man Easibleed Method

So you need your 1-man Easibleed Kit with a suitably low pressure tyre or another man, a jar, with some new fluid in it, a length of hose and your 8mm spanner.

The Easibleed Kit replenishes the old fluid with new so no worries there.

Here's the Easibleed Kit.



Attach the kit to the tyre, and then make sure the cap's a good seal. Also make sure it has fluid in it, then go round each nipple in turn bleeding any air out. When nice fresh fluid comes out with no bubbles, close the nipple.

The 2-Man Method

Get the other man into the drivers seat and make sure he can hear you. Also if you can remove the old fluid from the reservoir with a turkey baster or something then put in new stuff, it saves time.

Fit the spanner to the bleed nipple, and then fit the hose to the nipple. Put the hose into the jar and make sure there's a wee bit of fluid in it (this is there to make air bubbles easy to see and prevent air being sucked back up accidentally). Make sure the reservoir is full with new fluid.

Here's a picture of the hose into the jar on the rear caliper:



Tell the brake pedal man to slowly press the brake pedal down, whilst you open the bleed nipple when he reaches the bottom tell him to let you know but to keep the pedal pressed. Close the nipple then he can come off the pedal.

Do this until all the air bubbles are away and new fluid can be seen coming from the pipe. It's usually easy to tell because the old fluid will be dark and the new stuff light.

Here's a picture for comparison, old oil on the left, new oil on the right.



Do this to all the corners and the pedal should be nice and solid.

The bleeding order for ABS/Non-ABS cars is as follows;

Non ABS
Right-hand rear, left-hand front, left-hand rear and right-hand front.

ABS
Left-hand front, right-hand front, left-hand rear and right-hand rear.

Before you run out with spanners twirling there's something you should know.

The bleed nipples can be troublesome.

They have a habit of snapping off so you cannot loosen them to bleed the brakes.

So what to do? Well wire brush the rubbish and rust away from around the nipple (a dousing of WD-40 then leaving it an hour helps). Clout the end of the nipple with a hammer, then stick an 8mm socket of it and hit the end of that.

Try to loosen the nipple - if it's a no go then try tightening it slightly. If it's not going to move then get a blowtorch on it. Wait for it to go cherry red then let it cool in the air. Try again.

When tightening the nipples back up don't go over board as you will strip the threads. This is more of a problem on rear calipers.

Thanks to JB for the helpful photos.