Leaking cylinder?

Series tree · Jun 21, 2020

So I'm getting near to the end with my land rover finally! After renewing the whole braking system I decided to purchase a vaccum pump to ease bleeding, I found I only had to crack the bleeder valve 1/4 of a turn and no more otherwise air entered through the threads. Upon trying the brakes I still wasn't happy with them and the lack of complete firmness. I noticed that the front right caliper was not holding any pressure when operating the vaccum pump ( this surely must mean air is able to be sucked in) I clamped the pipe and it felt 80% there of what I would expect in firmness. Confused as the cylinder Is brand new, only old thing is the rubber pipe. What do you guys think I'm half tempted to just let the garage do it,, I've been under the vehicle for too many weekends now

tottot · Jun 21, 2020

Replace the flexi pipe and try again.

Webley1991 · Jun 21, 2020

I have found in the past that putting a smear of red rubber grease around the the bleed screw threads stops air leaking around them when bleeding the brakes.

It should also help stop the bleed screw seizing up through corrosion. This can be a problem with alloy cylinders and steel bleed screws. The brake fluid left in the screw after bleeding also attracts moisture which doesn't help.

Mark Frewin · Jun 21, 2020

Plus one for changing the flexible pipe. I used a Gunson Ezibleed on my series makes bleeding brakes very easy.

Colthebrummie · Jun 22, 2020

Try wedgingthe brake pedal hard down with a hammer or summat and leave it for 24 hours.

Col

Mark Frewin · Jun 22, 2020

If using a vac pump on the brake line it may be possible that you are drawing fluid the wrong way through the rubber seal (they are made for one direction of force.)
The reason for suggesting the Gunson Ezibleed is that there is constant pressure forced against the cylinder in the right direction keeping the air out while you open and shut the bleed nipple. No chance of air going back in.

Series tree · Jun 22, 2020

Do I then resume bleeding after the leaving something on the pedal all night? Yeah I will see what difference changing flexi pipe makes as there is obviously a reason that this cylinder is not holding a vaccum, thanks for the reply gents

Mark Frewin · Jun 22, 2020

The normal reason for changing the flexipipe is that the materials break down and when you operate the brake the flexi balloons and you effectively loose pressure/force resulting in a soft pedal. If the flexi was drawing in air with the vac pump then you would see a leak of fluid when operating the brake pedal. I would definitely get an Ezibleed system. Bleed under pressure they are only about £25 I've had mine years

Colthebrummie · Jun 23, 2020

Wedging the pedal down provides a lot of pressure in the system which sometimes forces any remaining air bubbles back up to the reservoir. Some people don't believe in it but it worked a treat on my series 3 and I've been doing it since the 70's. Doesn't always work but often as a last resort, it does. It does need to left wedged down for at least 24 hours.

Col

Leaking cylinder?

Series tree

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tottot

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Webley1991

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Mark Frewin

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Colthebrummie

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Mark Frewin

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Series tree

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Mark Frewin

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Colthebrummie

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