Bleeding brakes after master cylinder emptied?

[knicko]

Have just overhauled front and rear brakes and having removed the calipers, I have let the master cylinder drain. The colour of the brake fluid at the caliper ends was black and grotty, so good opportunity to drain it off.

Now that I have refitted everything, I am conscious that the bleeding will take a bit more work.

I know about bleeding the load sensing valve unit as well as all four calipers, but will I need to also bleed the MC and perhaps the ABS unit too? If so, do I just bleed from the unions that are at the highest point on these two units, or is there a particular way that they need to be bled?

 

[flint]

There have been a few posts on this recently, but basically the main thing is to keep the master cylinder topped up and bleed as normal.

 

[knicko]

There have been a few posts on this recently, but basically the main thing is to keep the master cylinder topped up and bleed as normal.

Bit late for that...MC already run dry. That's why I wanted to know what to do about bleeding more than just the calipers.

 

[flint]

Yes, I understood that. Just make sure that the mc is kept topped up while bleeding. Have you already bled it and have problems ?

 

[knicko]

Yes, I understood that. Just make sure that the mc is kept topped up while bleeding. Have you already bled it and have problems ?

No mate, I don't really know how to actually bleed the MC. It doesn't have a bleed nipple so I assume I can get pedal pressed while I loosen one of the unions?
Also is the ABS unit likely to need bleeding?

 

[StarCruiser]

The only thing I can add here is what others have said on other threads. That is to put a bock of wood (or similar) under the brake pedal so that the usual pedal travel is not exceeded and the seals don't get pushed into the crud zone within the MC.

 

[flint]

Here's one fairly recent thread where it got discussed : https://www.landcruiserclub.net/community/threads/bleeding-brakes-with-abs.146201/#post-1419264

You should be ok with just normal bleeding at the calipers, might take a couple of goes, but....keep the mc topped up.

 

[StarCruiser]

Don't know if it applies or helps but on the Smart I was advised to have the engine running while doing the bleeding and as usual start with the longest run of brake pipe. I assumed the engine was needed to be running for the ABS.

 

[knicko]

Thanks guys. Did loosen the unions at MC and ABS unit in the end and no air trapped actually. Rest of the bleeding went ok and happy with the result.
Only thing that was a pain was that I treated myself to new bleed nipples all round but these are proving to be a pain to seat properly and I am nervous about pinching them up any tighter. I might put the old ones back in!