Brake Pedal goes to floor everything new !! :(

[dan_sando88]

Hi Guys.

like most delicas my brakes weren't great but still worked so I thought it was time to change the pads, easy hassle free you say, I wish. changed the pads no problems there, bleed the system, sweet. check the pedal.... squishes to the floor! wtf. So check all the brakes and re-bleed.. still the same. OK must be the master cylinder. luckily I have a parts van so I swap the cylinder over.... re-bleeed and still spongy pedal!! and weak brakes. Ok strange coincidence but maybe the new fluid dislodged something in the old cylinders. take it in and get a new one, install, bleed again and STILL THE SAME PROBLEM! i have bled literally litres through the lines and checked for leaks everywhere and nothing! pedal is hard and feels good when the car is off but just sinks to the floor when can is on.

So does anyone have any suggestions or clues to what might be happening. The only thing I haven't replaced is the booster, but I thought the pedal would be hard if it wasn't working.

I'm taking it into a shop shortly if I can't sort this.

Cheers. Dan

[jessef]

how did you bleed it?

try with the engine on and start from the rear left (passenger side), then rear right (driver's side), then front left and lastly front right. That's the correct order. If done in a different order, air pockets can develop and cause exactly what you are describing.

I'm assuming the fluid level remains at the top and does not move when the pedal gets depressed? Or does the fluid level go down?

[dan_sando88]

how did you bleed it?

try with the engine on and start from the rear left (passenger side), then rear right (driver's side), then front left and lastly front right. That's the correct order. If done in a different order, air pockets can develop and cause exactly what you are describing.

I'm assuming the fluid level remains at the top and does not move when the pedal gets depressed? Or does the fluid level go down?

I bled from back to front with the car off. interesting! I have never heard of bleeding with the car on. I only have one bleed point on the back though (back driver) on the drum. I will give this a go thanks.

yeah fluid remains the same.

Thanks

[rezdiver]

did you pump the brakes while bleeding or let it gravity bleed?

[dan_sando88]

did you pump the brakes while bleeding or let it gravity bleed?

pumped the brakes while bleeding with the engine off.

[rezdiver]

using the pump method did you have 2 people doing this or just by your self.

not sure if you are aware of this but, using the pumping method you need a person on the pedal and fluid top up duty while the other person is underneath at the bleed nipple. open nipple, press pedal to the floor, close nipple release pedal and repeat. otherwise everytime you pump and release with an open nipple you suck air back in through the nipple. and it takes forever to do a proper job.

i just redid my brakes on my l300 and i used the gravity method, no pumping, open nipple and just sit there watching the grass grow while you slowly keep the reservoir topped off. once in a while you may need to give it a pump if the bubbles are going around a corner and fluid level does not drop but over all the fluid should drop on its own and drain by gravity. if you do pump release the pedal very slowly so as not to draw any air back up. i had lines full of air and it took a 1 litre bottle to do the bleed. rear brakes you may have to pump a couple of times more but front brakes they should just free flow slowly. i left the engine off.

[alti2d]

Not 100% sure about doing this with the brakes, but when a bled my clutch line I set up a partially filled container underneath the bleed nipple. I then ran a hose from the nipple to the container and made sure it stayed below the level of the fluid. I was able to pump the clutch, top the reservoir and easily bleed the line.

Again, I'm no expert, but it's better than watching the grass grow

[dan_sando88]

I did it with a helper pumping and topping up the fluid as I controlled the bleed nipple. working from furthest away to closest to the brake. total mystery It's in the shop now and even they are having trouble sourcing the problem. Very interested to find out what the problem is.

thanks for the help guys.

Dan.

[jessef]

well if you check all the lines, all the calipers and connections AND master cylinder for leaks and found none AND when you press the pedal/it sinks down yet the fluid does not move, points to air pockets still trapped in your system or the booster (air/fluid leaking in/out of it).

[jessef]

well if you check all the lines, all the calipers and connections AND master cylinder for leaks and found none AND when you press the pedal/it sinks down yet the fluid does not move, points to air pockets still trapped in your system or the booster (air/fluid leaking in/out of it).

[dan_sando88]

cars been in the shop for 2 days now and getting all the flexi lines replaced incase of bulging, mechanic is stumped everything has been tested.

[drrod]

Hard to imagine that the lines suddenly went bad. Brakes worked before the pad change and bleed now they don't. Call me crazy but I would not be thinking that your lines are "bulging".
I would bet on air somewhere in the system. Good luck with your search. Let us know what you find.
Rod

[dan_sando88]

so after 3 days and a nice big bill I now have brakes again. All the flexy brake lines were replaced and the whole system reflushed and all is good. I hate expensive, unexpected problems!!

[rezdiver]

did they tell you what the problem was?

[dan_sando88]

did they tell you what the problem was?

I don't think they found out what the problem actually was but whatever they replaced fixed it..