Brake issues

Hi All,

I've been changing my disks and pads this weekend, and as part of changing the pads, i wound the calipers back - using the g-cramp method.

However, after getting everything back together, no resistance on the brake pedal, rear brakes seem to be fine, but nothing on the fronts - any ideas what the issue might be? Servo or master cylinder?

I think the a piston is seized in one of the calipers, but the other should work ok?

Thanks in advance.

JoelC said:

Hi All,

I've been changing my disks and pads this weekend, and as part of changing the pads, i wound the calipers back - using the g-cramp method.

However, after getting everything back together, no resistance on the brake pedal, rear brakes seem to be fine, but nothing on the fronts - any ideas what the issue might be? Servo or master cylinder?

I think the a piston is seized in one of the calipers, but the other should work ok?

Thanks in advance.

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When you say no resistance on the brake pedal, do you mean the pedal goes straight to the floor?

Al2O3 said:

When you say no resistance on the brake pedal, do you mean the pedal goes straight to the floor?

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Feels like it, there is some resistance - but that is just the resistance of the springs in the pedal. Weird this is the back brakes seem to work ok, but there is definitely no hard bite as I would expect.

JoelC said:

Feels like it, there is some resistance - but that is just the resistance of the springs in the pedal. Weird this is the back brakes seem to work ok, but there is definitely no hard bite as I would expect.

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master cylinder has 2 parts one for rear one for front, try bleeding if it doesnt work youve inverted a master cylinder seal and it will need replacing

So you have a solid brake pedal? Your Landy slows down, but not that well so you think it's just the rear brakes that are working?

Al2O3 said:

So you have a solid brake pedal? Your Landy slows down, but not that well so you think it's just the rear brakes that are working?

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No, the opposite - at the moment it’s up on axle stands - there is no bite at all, I think @jamesmartin is right, besides which - the reservoir is pretty manky so i’ve ordered a replacement unit.

Thanks.

JoelC said:

No, the opposite - at the moment it’s up on axle stands - there is no bite at all, I think @jamesmartin is right, besides which - the reservoir is pretty manky so i’ve ordered a replacement unit.

Thanks.

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Ha. ha, he's rarely wrong.

Right, so new master cylinder fitted. Now the pedal goes straight to the floor first time, but if I pump it a couple of times I get bite, but then if I leave it, and press it again, it goes back to the floor and I have to pump it again.

I’ve bled the **** out of the system and I can’t see any air coming out - if I jiggle the bleed screw, I can get air bubbles coming out, but I think they are being drawn in the the via the bleed screw. Pumping the pedal I get fluid with not bubbles.

Any tips?

Yeah, is someone helping you bleed the system? Are you sure you are not drawing in air?

Having to do it on my billy-o at the moment. I bought an easy bleed kit which helps.

I am fairly sure there is air being pulled in somewhere, I just don’t know where. I’ve checked every joint and union.

Only other thing is if the new master cylinder is garbage. It’s an allmakes one

Given up for the day - started raining. However here are the symptoms:

Bleed the system, so there is no air coming out of the calipers, with the pedal pushed to the floor.
Pedal is soft and goes to the floor, pump a couple of times, and pedal goes hard, give it a few seconds and pedal goes to the floor again
If i crack off the bleed nipple on the front calipers, I get small air bubbles coming out - they look to me as if air is being drawn in, rears are fine, no air bubbles at all

I've checked all unions - cleaned off with break cleaner and checked for weeping, all seem good. I'e ordered some new flexi's, but i don't think its that. The calipers are brand new (allmakes) as well as disks and pads.

Stuck on finding either a leak or what I'm missing.

Perhaps a pressurised eazibleed is what you need to get good fresh fluid thru the system completely.

Cheers

neilly said:

Perhaps a pressurised eazibleed is what you need to get good fresh fluid thru the system completely.

Cheers

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I've done that, run at least 5l of fluid though the system with the EZ Bleed kit, but I still have air bubbles, so it must be drawing in air somewhere.

OK, Sorry, when you said you were pumping the brakes I assumed you were manually pumping as well to bleed the brakes.

Cheers

Get someone to work the pedal. You bleed it the old way and you get to see if there are any leaks when the pressure is on.

Anyone know what the pitch on a flexi brake hose is? I know its M10, but all i can find is course threads. Any idea where stocks them that might have them locally, screwfix seem to be all course thread nuts.

crc1487 is the number

I had a similar issue. Turned out to be a shagged caliper, 2 pistons where seized and the caliper was drawing in air from somewhere.

Changed both and pedal is perfect

jamesmartin said:

crc1487 is the number

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Thanks James - I can't find anywhere locally that stocks them, going to have a trip round the local nut and bolt merchants tomorrow and see what i can find

I would say a better choice would be one of the motor factors. Eurocarparts or similar , or even pop down the local car repair / garage and ask them.

Cheers