bleeding brakes

[shedrool83]

Having issues bleeding the brakes on my b4 cab project.
I have swapped the mc and bled it ,bled all the calipers twice and the pedel is still going to the floor.

I saw a thread relating to the brake bias valve on the rear beam needing a 6mm bit put in somewhere but don't know if i did it in the right place or not.

anyone got any ideas this is really getting to me now after two hours and 3l of brake fluid.

Btw i have been doing the two person method of pedal down open bled nipple,close nipple pedal up and repeat.

[quattromnc]

Sounds like either there's a leak somewhere, or the master cylinder seals have gone. Even with poorly bled brakes there should be some resistance at the bottom, if you've put that much through, that points to a problem not just bad bleeding.

[shedrool83]

Sounds like either there's a leak somewhere, or the master cylinder seals have gone. Even with poorly bled brakes there should be some resistance at the bottom, if you've put that much through, that points to a problem not just bad bleeding.

I am getting resistance at the bottom of the pedal and if i pump the pedal it is going hard. I replaced the master cylinder for a new one that came with the car when i bought it .

[quattromnc]

Ok, what method are you using? Pressure bleeder, or by foot? It may be worth changing method?

Also could it be the wrong MC?

[diesel des]

Try slackening the pipes at the master cylinder and bleeding it first.

Sent from my LG-H955 using Tapatalk

[Monkeymagic]

Also try bleeding with engine running.

[shedrool83]

Using the foot method . i bled the master cylinder first after fitting it and i looks to be the right one although a cheap version .

[steve briance]

I've just had a major success after a thread on brake bleeding suggested bleeding the calipers with them unbolted from the carriers.

I was having spongey pedal issues which improved when pedal pumped and when i had a further look at my rear calipers - the bleed nipples were not uppermost and therefore would never be able to expel all air bubbles no matter how much fluid passed through or bleeding technique used. Any air in the system would always make its way past the bleed nipple and stay there.

I removed the rear calipers, held them nipples uppermost and bled out some more bubbles and, lo and behold it was job done.

Weirdly my calipers seemed to have the fluid hose going in to the upper most hole which you might think meant the nipples and hoses were the wrong way round, i thought that but there was no way the hose was going to reach the other hole without some nasty bending.

[shedrool83]

I've just had a major success after a thread on brake bleeding suggested bleeding the calipers with them unbolted from the carriers.

I was having spongey pedal issues which improved when pedal pumped and when i had a further look at my rear calipers - the bleed nipples were not uppermost and therefore would never be able to expel all air bubbles no matter how much fluid passed through or bleeding technique used. Any air in the system would always make its way past the bleed nipple and stay there.

I removed the rear calipers, held them nipples uppermost and bled out some more bubbles and, lo and behold it was job done.

Weirdly my calipers seemed to have the fluid hose going in to the upper most hole which you might think meant the nipples and hoses were the wrong way round, i thought that but there was no way the hose was going to reach the other hole without some nasty bending.

i'll give that a try . I did notice the nipples on the rear are about the middle of the calipers.

[steve briance]

def worth a try then. Mine were in the middle and it looked like that would leave a tiny part of the piston slightly beyond the nipple. It wasn't much but i still got a few bubbles and my pedal was a lot better afterwards. I had bought and tried a sealey VS820 pressure bleeder which was great but was never going to solve my problem but it did make the whole thing really easy on your own and it didn't involve letting your spare tyre down and using it as a source of pressure!

[diesel des]

Any pictures of the offending calipers? Are the original?

Sent from my LG-H955 using Tapatalk

[shedrool83]

Any pictures of the offending calipers? Are the original?

Sent from my LG-H955 using Tapatalk

only pic i have atm.I will take a better one of the nipple later today.

[shedrool83]

Removed the caliper as suggested and bled again using a sealey vs020 and now have a pedal . Cars on axle stands atm so no idea how it will brake when driving but fingers cross .

Thanks for the input help alot .

[steve briance]

Sounds encouraging!