Replacing brake bleed valve

[james250]

I need to replace one of my brake bleed valves which does't allow fluid to be drained because somehow the rubber cap came off and its just seized up with dirt. I purchased a new valve which is cheap anyway. Question is to replace it should i have someone press on the brake gently and let fluid come out as i'm unscrewing it and then while pedal is still pressed quickly put the new valve in?

[johnatg]

Don't press the brake pedal whilst you change the nipple - that just guarantees that you lose more fluid. It is worth clamping the hose if you can do so without damaging it - that really needs a purpose made clamp. Just unscrew the nipple and screw the new one in as quickly as possible. Then you will need to bleed the brakes in the normal way as you are bound to have lost some fluid and let some air into the system.

These things are just nipples - there is no valve involved.

[jumbojake]

agreed .. clamp, bleed and wipe... just be careful getting the old one out, especially if you fear it is seized. you don't want to snap it off in the caliper (I did that once on an old Renault (oops)

[steve2006]

A good overnight soak in penetrating fluid, use a short good quality single hex ring spanner and work the nipple in and out when it does start to turn. A little blowtorch heat may also help.

[Britprius]

You can buy a set of bleed nipples with a one way valve built in. This makes bleeding very easy, and a one man job.
The the bleed nipple is slacked off, but a spring loaded one way valve built in stops fluid escaping, but more importantly stops air entering the system.
Pushing the brake peddle opens the valve by light pressure in the system allowing fluid, and any air in the system out. The valve then closes as the pressure drops, and you take your foot off the brake peddle air cannot be drawn back into the system. So pumping the peddle a few times "making sure there is enough fluid in the reservoir"  then tightening the bleed nipple is all that's required to bleed the system. No pipes, bottles, helping hands, or pumps required.

Unless you have a hybrid then it's a different ball game.

John.  

[Howplum]

1 hour ago, Britprius said:

You can buy a set of bleed nipples with a one way valve built in.

Really! That sounds great. Where?

Anyway, yes, great care is needed in removing the old nipple. If the hexagon is close to the caliper then there is a greater chance of success than if the hexagon is near the open end.

[Britprius]

50 minutes ago, Howplum said:

Really! That sounds great. Where?

Anyway, yes, great care is needed in removing the old nipple. If the hexagon is close to the caliper then there is a greater chance of success than if the hexagon is near the open end.

Your local car parts shop should have them or through eBay. Be sure you get the correct thread for your car.

John.

[jumbojake]

I think this is the type you refer too .. I'll certainly be on the look out for some

Flyer_Entlueftungsventil.pdf

https://www.louis-moto.co.uk/artikel/stahlbus-bleeder-valve-with-banjo-bolt/10002823?filter_article_number=10002823#description