Jump to content

Recommended Posts

Anyone come across this problem before?

Been trying to fix a problem with rusty rear brake discs... so bought a new (Lucas) Master Brake Cylinder. After reading around this forum and others, it seems the best way to "prepare" the MBC for installation, is to pre-bleed it in a vice - before installing to vehicle.

It's the first time I've tried this....

After 2 hours of trying (in the vice) ... using brand new DOT 4 fluid - I gave up. See photo! I'd rigged up a closed loop system... and allowed up to 30 minutes between pumping sessions - to allow any trapped air to "Rise".

For the love of god... I could not get the rear brake circuit free of air bubbles... I've now sent it back for a replacement. The front circuit was perfect - nice clear, bubble free, fluid flowing around the loop...

Is there some trick I'm missing?


Share this post

Link to post
Share on other sites

Sent the (new) Lucas Master Brake Cylinder back to Paddocks for a replacement. 3 weeks later... a new one arrived... (this week).

With the new one, I followed the same process - i.e. bled it in a vice - with a continous loop setup on both front/rear outlets. This time, no bubbles on either circuit. Thank f**k for that.

So... that's 2 Lucas MBCs in a row I've bought that were defective - both on the rear circuit...

"Top tip": When installing an MBC, bleed it in a vice first so you can ensure it works properly. In my case I had no idea the rear brake circuit wasn't working properly - only evidence was rusty rear discs.

Hopefully this one will last a few years!

Share this post

Link to post
Share on other sites

Good advice there, I think a lot of us take it for granted that because it is new it will be perfect.

I always used to bench test my new glow plugs before fitting, you would be surprised how many are dead before they are even fitted to the engine!!!

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy