34 replies to this topic

[nollyd]

i had similar problem,pleeeease be sure to get them right before taking it out on road,i had low pedal but after a pump it seemed ok,my problem was air getting in thru the rubber on the rear cylinder,only noticed when a pool of brake fluid appeared on factory carpark,no brakes at all.i bled my brakes the old fashioned way,three pumps,hold down,release nipple while pedal down,tighten nipple and release pedal.repeated loads of times at each corner.my brake pedal at almost top now.but where brakes are concerned check and check again.then check again.hope this helps.

[dklawson]

Check the rear for adjustment!!

 

+1 on that  !!!

 

Generally when the pedal is low on the first pump and higher on the second pump the shoes are not adjusted properly.  Proper rear brake adjustment does not mean the elevated wheel spins freely.  Jack up a rear wheel and release the parking brake.  Adjust the rear brakes until they lock up, then loosen them one click at a time until the wheel can be spun by hand and stop within 1 revolution.  You should hear a bit of rubbing of the shoes on the drum.

[cal844]

My 1275 was fine, then a few weeks ago had a long pedal... Adjust the rear 1 turn a side and its good to go!!

[mini_mad69]

Rear brakes are adjusted, wheel does around 1/2 to 1 turn when spun dragging in the shoes.

Just bled it at 40 psi with the eazi bleed and still no joy at all. pump pedal and get pressure, leave it for 5 seconds and it goes to the floor again. Pumping it and then holding pressure the pedal stays firm.

[cal844]

DONT use the eezibleed, it will close the PRV

[KernowCooper]

I have seen a escort with similar where the seals were tight and drawing the pistons back into the caliper, get someone to pump the pedal up hard and observe the pads/pistons from the front and see if the pistons are being overly drawn back.

 

In fact I had the exact same with my mates GSXR 1000

Edited by KernowCooper, 23 May 2014 - 08:16 PM.

[dklawson]

I re-read (skimmed) the previous posts to review what you have tried.

 

Until you mentioned the ez-bleed I am not sure we spent any time discussing how you were trying to bleed the brakes.  Let's spend a moment talking about other methods of bleeding and what each can do.

 

Rapid Pump:

Some people like to pump the brakes in rapid succession 3 or 4 times and then hold the pedal firmly to the floor.  An assistant then opens the bleed nipple (with tube attached) so the trapped fluid spurts out into a catch jar.  The method has been used for decades and if the air is already in a wheel cylinder or caliper this method can work the air out of the system.  This method doesn't work well if the system has been drained completely and it does not work well if there is a rear subframe mounted proportioning valve.  In a totally dry/empty system this method can take a while to move fluid back into all the pipes, hoses, and cylinders.  Where a proportioning valve is fitted this method can cause the valve to close without moving any fluid to the rear wheel cylinders. 

 

Two Person Flush:

This method also involves a bit of tubing, a catch jar and two people but the method is slower.  One person works the pedal in the car, the other opens and closes the bleed nipple as follows.

At the wheel the first person opens the bleed nipple 1/2 turn, then call "Down" to their assistant.  The assistant SLOWLY depresses the brake pedal until it reaches the floor then hold the pedal in place.  With the pedal down, they call "Down" to the person at the wheel.  The person at the wheel closes the bleed nipple and calls "Up" to the assistant who slowly lets the pedal back up to its rest position.  With the pedal up the assistant calls "Up" back to the person at the wheel.  The process then repeats over and over until no bubbles are seen moving through the tubing attached to the nipple.  The reservoir must be checked often to insure it does not go empty.

 

This method moves any/all old fluid out of the system.  It also slowly pushes air down the lines and through the valves and cylinders until the system is full of fluid and no air.  It still has the drawback that if you push the pedal too quickly the proportioning valve can close.  With slow pedal pumps the method generally works to completely flush and bleed the system regardless of whether it had been completely empty or not.

 

Gravity:

Some people who use the two methods above like to move the largest portion of the air through the system by gravity bleeding.  As its name implies, there is little to be done.  A drain tube is connected to one of the bleed nipples and the nipple opened wide (at least 1/2 turn).  The reservoir is topped up and the person goes away or waits patiently nearby.  Over time the fluid will flow down the lines pushing the air ahead of it.  Once the fluid is moving out of the bleed nipple without too many bubbles, one of the two methods above is performed to complete the bleeding process.

 

I am not a big fan of vacuum or pressure bleeding but to each his own.  Pressure bleeders seem to work well for some but my cars have proportioning valves which can close off with a pressure bleeder the same way they close off with rapid pump bleeding.

[mini_mad69]

Tried all meathods except vacuum bleeding.

 

I've always used my eazibleed without any issues before. This is the same setup the car was using 3 years ago, just with new lines and rebuilt calipers and rear wheel cylinders.

 

I think I may have to try a new master cylinder.

[dklawson]

I suppose the seals in the master could be worn enough that some fluid leaks by until the skirts on its seals are pushed against the bore.  I do have one additional suggestion before you pull the master to work on it.

 

Assume for a moment that there may be someplace between each caliper/cylinder and the master where air might be trapped.  Though messy, crack each fitting open sequentially between the master and the wheels.  Start at the master, disconnect each hard pipe and pump the pedal enough to see fluid come out, then tighten the fitting again.  Move down the line to the next fitting/junction and do the same.  By the time you reach the wheels you should have allowed any trapped air to escape, particularly for the lines to the rear wheels.  If this fails to address the problem... perhaps it will be time to work on the MC.

[mini_mad69]

I started doing that, but only on the front as it was only the front brakes not working.

 

I just took my master cylinder off, and the seals seem fine and the bore is smooth.

 

Out of ideas now.

[cal844]

Does it have the valve thing on the bulk head?

[mini_mad69]

Yes it has the "valve thing" on the bulkhead.

 

I have also tried without it.

[mini_mad69]

Something to mention, is now I'm using my easibleed at a higher pressure. I've noticed, If I hook up the easibleed, bleed out the brakes. I have a great solid pedal! excactly where I'd want it!

This is leading me to think back to my previous theory of the pistons retracting to much in the calipers? The easibleed could possibly pushing the pistons out a little and then holding them there? So when pushing the pedal the pistons are in the right place?

[Alex_B]

Something to mention, is now I'm using my easibleed at a higher pressure. I've noticed, If I hook up the easibleed, bleed out the brakes. I have a great solid pedal! excactly where I'd want it!

This is leading me to think back to my previous theory of the pistons retracting to much in the calipers? The easibleed could possibly pushing the pistons out a little and then holding them there? So when pushing the pedal the pistons are in the right place?

When you do this, do you mean when you have bled the system and the eezibleed is still pressurising the lines or after bleeding is done you disconnect the eezilbleed and the pedal is firm? 

 

[mini_mad69]

System is still pressurised with eezibleed.

 

There is also some drag on the wheels when spinning them. When taking the eezibleed off again, there is no drag at all, the wheels spin and spin and spin.

 

 

How far should the pistons retract when letting off the brakes? I took the pads out to see if there was any slack betweern the pads and the discs all good.

 

I ran the car, in gear, pumped the brakes and ran the car with the brakes on to try and get some heat into the brakes to see if that would free them up and get a pedal. No change.